Ramblings on the Future of Humanity

Technologies for Asteroid Capture into Earth Orbit

2011-07-07T07:51:00.001-04:00

The following is my presentation “Technologies for Asteroid Capture into Earth Orbit” given at the International Space Development Conference in Huntsville, Alabama, on May 19, 2011.

The focus of this presentation is on a specific technical approach which enables us to capture an asteroid using essentially current technologies; the missions, tools, and complications of that approach; and then some asteroid selection criteria and a few specific asteroid capture opportunities.

Using the asteroid 99942 Apophis, I outline a possible capture mission, its requirements, and a timeline.

So why capture an asteroid? The main reason is to gain convenient access to its resources. Even a relatively resource-poor low-iron, low-metal LL chondrite contains 20% iron, significant quantities of water and other volatiles in the form of minerals such as clays, and oxygen to burn.

The asteroid Apophis (likely one of those LL chondrites) contains enough materials to construct about 150 five-gigawatt solar power satellites at 25,000 tons of steel and silicon each, plus Kalpana One style habitats for 100,000 people, all shielded by the slag remaining after iron is smelted out of asteroid ore. The oxygen freed from iron compounds during smelting amounts to well over a million tons more than is needed for the habitats, valuable fuel mass for ion thrusters to move the habitats and solar power satellites into their chosen orbits and to spin them up.

Of course, a space habitat providing food, water, oxygen, fuel, construction supplies, gravity, radiation shielding, and skilled human workers situated above much of the Earth’s gravity well is an ideal platform from which to continue the exploration and exploitation of space.

And we should not forget that placing an asteroid into a stable Earth orbit prevents it from colliding with the Earth.

So, how do we capture an asteroid? Even a tiny one masses millions of tons, and we don’t yet have the technologies to manhandle them and put them wherever we want. Luckily, we don’t have to. When a spaceship or asteroid passes close to a planet or large moon, its orbit is changed, sometimes dramatically.

In principle, the Earth can impart a delta-V of up to 60km/s to an asteroid in orbit around the Sun, although in practice the limits are a small fraction of this. More importantly, small changes in the position or timing of an existing close approach are enormously magnified.

We aren’t limited to the Earth, in that close encounters to other planets might be used to alter an asteroid such that it passes close to the Earth at a later time where its orbit can be further tuned by the Earth’ gravitational field.

A point I’d like to emphasize: In my opinion, gravitational slingshots are as much art as engineering, especially when considering the variations involved in multiple slingshots around one or more bodies. The people who dreamed up the Cassini and Messenger missions are both geniuses and artists, and I have every confidence that they can find suitable mission plans to capture any potentially hazardous asteroid into Earth orbit, although the missions may be very long and complex thanks to a shortage of appropriate close encounters and/or the need for significant changes to the asteroid’s orbital parameters.

When selecting an asteroid for a potential capture, the most important consideration is simply the proximity of an asteroid’s orbit to a useful keyhole through which the orbital engineers can design a capture mission in a reasonable timeframe.

The second consideration is the size of the asteroid. Bigger is not better when a 1 kilometer asteroid masses fifty times as much as Apophis, and thus requires a fifty-fold increase in the product of mission time and fuel mass. On the other end, a small 120m LL asteroid massing 2 million tons (and relatively poor in useful metals and volatiles) still has sufficient materials to build a single small Kalpana One style habitat for 8,000 colonists plus a dozen 5 gigawatt SPSs. Thus I view 120 meters as the smallest asteroid worthy of (first) capture, since it is barely large enough to build a permanent habitat rotating at 3rpm for Earth-normal gravity and with adequate radiation and meteoroid shielding.

Another consideration is the V-infinity of the asteroid, because slower asteroids are easier to move a distance large enough to make a significant difference in the slingshot.

The potential magnitude of a gravity assist is also constrained by how close to the center of the Earth the asteroid passes – and I think it’s important to keep it out of the lithosphere. Also, for a rubble pile we don’t want to pass closer than the Roche limit or the asteroid may be torn apart by tidal effects, much as Jupiter’s tide tore the comet Shoemaker-Levy into 20 fragments. The actual Roche limit depends upon density, but is likely to be of the order of 20,000 kilometers for a rubble pile asteroid passing near the Earth, and perhaps 5,000 kilometers for the Moon.

One might think that the composition of an asteroid would be the number 1 criteria, but in reality most asteroids should be quite valuable (see Mining the Sky by John S. Lewis). A common carbonaceous chondrite might contain 25% nickel-iron mostly in the form of metal grains, 10% water, and several percent carbon plus everything else needed for life in space. But even a lowly LL chondrite will work.

The last consideration here is the opportunity for intercept missions. We need to modify an asteroid’s orbit when it is easy, some months or years before the targeted close approach. This is difficult for a high-inclination or long-period asteroid because it might only approach closely enough to the Earth for low-delta-V intercept missions once every ten or a hundred years. But an asteroid with a two-year period might present suitable launch windows every two years. Also, for asteroids with periods close to a year and with low inclinations, there may be two launch windows per year as the asteroid passes inside and then outside the Earth’s orbit.

This table presents some possible asteroid capture candidates as of 25-APR-2011, all brighter than 24^th magnitude and expected to pass within 120 Earth radii in the next 50 years. Some of these may be eliminated by further refinement of their orbital parameters, while others can likely be added as new asteroids are discovered, or as orbits are corrected for known ones.

The entries on this table were gleaned from the Near Earth Object Close Approach database. The various tables, databases, and lists at the NASA web site are inconsistent, sometimes even on the same page. For example, the orbit visualization tool often has significantly different closest approaches than the “close approach” data on the same page.

A side note: Many asteroids have only been observed over a few days, resulting in large uncertainties in their orbital parameters. The shapes, diameters, and masses of most asteroids are estimated, not known. Diameters are estimated from an asteroid’s brightness and distance. But we can’t measure the actual albedo, and observations at multiple wavelengths are used to judge the asteroid class, and from that a typical reflectivity, and from that a formula results in an estimate of the diameter, and assuming an average density, we calculate the mass. This process has extremely large error bars. In April of 2010, radar imaging resolved the asteroid YU55. Previous estimates were that its diameter was 140 meters and its mass 4Mt. The actual measurement revealed a diameter of 400 meters and an estimated mass of 87Mt, a 22 fold mass increase.

Let’s consider these asteroids.

Apophis is fairly well characterized, although it may not be an LL chondrite, and may therefore have a different albedo, diameter, and mass. As a candidate for Earth-orbit capture, it has the advantages of passing quite close, and relatively slowly, plus launch windows occur in Aprils and Octobers near close approaches, suitable for a 1, 1.5, 2, or 2.5 year mission. It masses 27 million tons, roughly twelve times larger than the minimum useful capture size.

2001 WN5 is a bit on the large side, but it may pass about halfway between the Earth and Moon in 2028 which offers an opportunity to adjust its subsequent Earth approaches in 2037 and 2046. But being more than 20 times as large as Apophis means a lot of fuel is required, so 2001 WN5 will have to wait for a later, poorer opportunity, probably with a robotic mission.

2005 YU55 is three times as massive as Apophis, and approaches Earth, Venus, and Mars, giving multiple possibilities for gravity assists. Next year it will pass about 20% closer than the Moon’s orbit, but it won’t be that close again for quite a while. It makes frequent approaches, about every 11 years, with relatively close approaches in April of 2021, 2032, 2043 (etc), and in November of 2022, 2033, 2044 (etc). We can likely tune one close approach to allow a closer approach 11 years later that can lead to a capture 11 years after that.

1999 AN10 is a large (50x Apophis), fast, and dangerous asteroid which will pass about as close as the Moon in 2027. It is large enough to build 7,500 5-Gigawatt Solar Power Satellites, or to house 2 million people in a 2 mile diameter habitat. Actually, we can solve Earth’s energy problem for the next thousand years AND build a habitat for one million people, with materials to spare. While it is difficult to capture, it should be worth the effort.

2009 WM1 is only half the size of Apophis, and should be easy to capture some fifty years from now at its next close approach.

Lastly, 1999 RQ36 is 7 times the size of Apophis and passes 1.2 Lunar distances from the Earth in 2060. It, too, won’t be easy to capture, but is also worth the effort.

I’d like to point out that every one of these asteroids were placed into their current orbits by a slingshot around the Earth, a fact clear at a glance at the orbital simulation on the NASA web site. One of the principles of orbital mechanics is that an orbiting body (in a 2-body system) will always return to the altitude and velocity vector of its last orbit change. Ignoring hyperbolic orbits, one near Earth pass means more, until the body collides with the Earth or is deflected away by another planet.

Note, too, that capturing Apophis in 2029 would provide ample fuel to capture those big asteroids a few decades later.

But it seems that nothing is ever simple. Part of the problem is that we don’t really know much about asteroids. Many of them appear to be rubble piles, and in some cases these spin so rapidly that their shape is constrained by their spin, yielding flying-saucer shapes. Others are contact binaries which might be exceptionally awkward to manipulate. We have more options with solid bodies, but we can’t plan on that.

So how do we apply thrust? Two ways come to mind: dock and push, or use a gravity tractor to pull. Gravity tractors can only apply tiny amounts of thrust, but that might work, especially on longer missions. It would also help to dangle heavier components such as nuclear reactors and fuel as close as possible to the asteroid, with the thrusters some distance away so they can aim off to the side without much loss of thrust efficiency. But a 1,700 ton mass dangling 170 meters from the center of Apophis would be needed to apply the necessary delta-V over a 10 month period. Gravity tractors generally require very long missions.

We can dock with an asteroid and push against it in a traditional way, but there are complications due to microgravity and asteroid rotation. It is possible that a number of cables could be looped around the asteroid to hold the tugship securely in place. Even then, a spinning asteroid means that thrust can only be applied during a fraction of each rotation, wasting thrust and fuel to the extent that the applied thrust isn’t directed in the correct vector.

Let’s consider a specific example. The asteroid Apophis will approach Earth to within 30,000 kilometers on April 13, 2029, significantly inside the orbits of our geostationary satellites. If we do nothing, the Earth’s gravity will slingshot Apophis into a new orbit as it deflects it by about 28 degrees and boosts its velocity by 3.04 km/s. The result of this is that Apophis changes from a 0.89 year period Aten class asteroid orbiting mostly inside the Earth’s orbit to an Apollo class asteroid with a 1.167 year period and an orbit mostly outside of the Earth’s. I should point out that we don’t yet know with any degree of certainty exactly what the resulting orbit will be, because tiny changes in the position of closest approach have a huge impact on the resulting orbit. The period I’m quoting here corresponds to the keyhole that targets an Earth impact in 2036.

My main point is that delaying Apophis’ arrival at the Earth’s orbit by changing its velocity by only 10 cm/s results in a 1.5 km/s reduction in delta-V - a velocity gain of a factor of 15,000. I chose that particular slingshot because it results in a semi-major axis of exactly 1 au, with a period of 1 year. I used a program named GravitySimulator by Tony Dunn to model several Apophis orbit variations, and simultaneously to gain a true appreciation of the art and genius needed to find useful orbits.

The Tisserand criterion indicates that it’s possible to change Apophis’ eccentricity to zero at the same time, although that would result in an inclination of about 10.5 degrees, and requires a much larger delta-V. In any case, what we really want is not a near-Earth orbit, but rather a subsequent low-speed slingshot around the Moon to remove excess velocity and drop the asteroid into Earth orbit. That may require some finesse and multiple slingshots, but I’m confident it can be done. Look at the success of Cassini, Messenger, and other missions that have relied on gravity assist slingshots to achieve what once was considered impossible for our current technology.

We still need to give Apophis that 10 cm/s nudge. I don’t suggest abrupt changes from nuclear bombs or high-velocity impacts, partly because we need finesse to fine-tune the orbit, and that’s best done by the equivalent of titration. We need a tugship, a long-mission, highly fuel-efficient spacecraft to gradually move the asteroid into a new orbit.

Magnetoplasmadynamic or VASIMR thrusters are likely the best choice to apply delta-V, as their high exhaust velocities reduce the total fuel mass needed, they can generate significant levels of thrust, and they should be able to achieve sufficiently high reliability.

Of course, we need to push or pull the asteroid, which isn’t simple, partly because they are rotating, undoubtedly along an inconvenient axis. And they have enormous angular momentum which we can’t simply cancel. This means we’ll either have to dock – not land – at an appropriate location and thrust a fraction of the time, or use a gravity or magnetic tractor approach which might limit us to lower thrusts and longer missions.

Note that ion thrusters take copious amounts of energy. 25 megawatts can be generated by a 300 by 300 meter solar array, or by a single compact nuclear module available commercially. We do have a lot of experience with high-power nuclear modules in submarines and aircraft carriers, so that’s an option I personally lean toward, but politics may dictate a less proven approach. Also, working fluids and cooling grids need to be addressed for nuclear or for solar dynamic electric generation.

Given an appropriate power supply, we still need enough time and fuel to move an asteroid. So how much do we need?

From our mission-time derived flight plan, we compute the needed delta-V, and conservation of momentum allows us to compute the needed momentum change and the product of fuel mass times exhaust velocity. The asteroid’s mass is a given, but we can choose to some extent our mission time, and thus the needed delta-V. Double the mission time, halve the delta-V.

Note that doubling the exhaust velocity quadruples the needed energy (100 times the energy is needed for 10x velocity for a given amount of fuel). But doubling Vex also halves the fuel mass required, so the net effect is doubling the required power for a given thrust duration. At a specific impulse of 5000, consuming 55 tons of fuel over a 10 month period requires 5 megawatts of continuous power.

With a lot of energy, we don’t need much fuel at all. These numbers are all well within our technological capabilities. Of course, additional fuel will be needed to deliver the tugship and its load of fuel to the asteroid, but again, the numbers are within our capabilities. We can do this.

However, remember that Apophis is rotating and we may only be able to apply thrust half of the time. This doubles the thrust and power required.

I’m proposing a mission with two main phases and a three-year (or so) timeframe.

The first phase is to launch the necessary components and assemble them in orbit, some time in 2027.

The actual deep-space phase begins with a lunar slingshot for intercept injection in October of 2027, and docking with Apophis some 5 months later. This requires 3 km/s of delta-V, and about 15 tons of fuel.

We would grapple Apophis, and apply 400 Newtons of thrust (enough to deliver 1.0 cm/s/month of acceleration) for half of every 30-hour day. Ten months of thrust consumes 55 tons of fuel. Then there is a three-month coast until the slingshot.

The major slingshot must occur on April 13, 2029. The goal is to change Apophis’ orbit to achieve a lunar slingshot 1 year later to capture the asteroid into Earth orbit. Note that the initial thrust moves Apophis further from the Earth, and the subsequent lunar slingshot is necessarily even further out.

I want to talk briefly about that tugship.

It must support an extended deep-space mission, providing everything the crew needs to thrive. My supplies estimate assumes ammonia provides hydrogen for carbon dioxide recycling, and food to be dehydrated.

My mission plan requires 55 tons of fuel to change the asteroid’s orbit, plus 15 tons for the intercept and docking, plus contingencies. I’d suggest at least 100 tons total, perhaps more. Note that if properly oriented, the fuel can provide significant radiation shielding during the trip to Apophis, and then the asteroid itself provides even more, especially if the crew quarters can be partially buried.

We need to apply 200 newtons of thrust continuously for 10 months, or double that for half of the time. We’d need to double the power as well, 10 megawatts total. A 200 meter square array of 25% efficient solar cells generates 12 megawatts, the extra needed since ion thrusters aren’t 100% efficient.

Lastly, we need some way to grab hold of the rotating asteroid. I suggest using 6 harpoons with 1-km lines launched around Apophis, the ends retrieved and securely tied to the tugship. This would function as an effective net and friction applies sufficient traction to apply thrust even at high angles of attack. We could break several of the lines and still hold on. Note that this is a good example of where people can easily accomplish a task which might be nearly impossible for an automated system.

This project plan assumes a separate launch of a construction shack housing six or more workers for several months.

Their job is to assemble all of the components, as I’d expect at least 5 launches of 50+ tons each are required.

-Two launches for the solar panels and supporting structures – total 100 tons

-Two launches for the fuel and thruster assemblies – another 100 tons

-One launch for the tugship (crew quarters) itself

-The construction shack is a sixth launch, and the assembly crews, mission crew, and supplies are likely two more man-rated launches. Note I’m assuming the assembly crew is launched early, and the mission crew at the last minute, because the deep-space mission already requires a very long time. The number of people in each is an estimate, of course. While 6 workers may suffice to assemble the tugship during a two month project, double the people would simplify training, ease workloads, and provide significant redundancy.

-Likewise with the deep-space mission crew. Two people may be able to handle the workload, but that is cutting it close. I’d suggest four at a minimum, and six is better.

Continued research tops the list of the several logical next steps we should take. NASA is ideally suited for several of these, and the continuing search for potentially hazardous asteroids identifies the same candidate asteroids as a search for potentially capturable ones.

We do need to address several legal issues, which pose a serious problem for Western civilization private enterprise. Key among this is the right to own and exploit objects in space. If a person or company does not have the right to exploit space-based resources, they can have no incentive to acquire them, and the future of humanity in space is effectively dead.

We must also address the liability of moving asteroids. Certainly this should be done with the utmost care and intense oversight tempered with some sense of practicality. For example, the adjustment to Apophis orbit that I propose appears to pass through the 2036 impact keyhole. Does that mean we must move the orbit out and around that keyhole, or simply that we use reliable, even redundant systems, and closely monitor to track the potential need for additional intervention? I’m afraid that science and logic may have little to do with the outcome of that discussion.

We need to design and build a tugship using thruster and power technologies available in an appropriate timeframe. Of course, that research is an excellent task for NASA’s Marshall Space Flight Center. I think the biggest challenge here might be in supporting deep-space, long-term missions with the human crews I believe are necessary to get the job done.

The bottom line is that we CAN capture asteroids into Earth orbit, thanks to the amplification of delta-V due to gravitational slingshots.

There are several candidate asteroids today, and there will be more tomorrow. Also, I did not look for opportunities where the asteroid close approach was to Venus, or Mars, or Mercury, and there is every chance that good candidates exist although longer missions (and an extra slingshot or two) would be required.

The most important consideration to me is that capturing an asteroid such as Apophis places millions of tons of raw materials into Earth orbit where we need them to build solar power satellites, permanent orbiting habitats, and to advance humanity’s exploration and further exploitation of the vast resources of space.

Lastly, we should never forget that capturing a potentially hazardous asteroid converts a dangerous threat into a resource of immense value.

President Obama needs a grand goal for NASA and the nation in the next decades, one comparable to Kennedy’s “We choose to go to the moon in this decade.” I believe that capturing Apophis into Earth orbit is such a grand goal, with benefits to global energy and warming (via those solar power satellites), and to space exploration, and to permanent, self-sustaining habitats in space. And it removes a threat to the Earth.

If you agree that we need a space-faring humanity and that exploiting asteroids is key, if you agree that sending cheap solar energy to Earth simultaneously helps humanity and reduces global warming, if you agree that we should act to prevent asteroid impacts on the Earth, then please share the word. Follow this link (Project Apophis) and tell President Obama that he holds the key to the future of humanity in space, that capturing Apophis is feasible, affordable, solves many problems in a single step, and is a Grand Goal worthy of his – and this nation’s – focus. Thank you.

A Project Plan for Space Based Solar Power

2011-02-22T19:21:00.001-05:00

OVERVIEW OF A SPACE BASED SOLAR POWER PROJECT

In my post, Space Based Solar Power, I present an overview of SBSP and its value to humanity. I also propose the use of asteroids for raw materials to reduce the cost to profitable levels. Still, the construction of the first Solar Power Satellite (SPS) is special, as we must incur all of the up-front (bootstrap) costs in addition to building the SPS itself. I will demonstrate that it still can be a profitable venture. However, this project plan targets the initial construction of a dozen SPS’s, because the slag by-product of that much steel is the correct mass of shielding needed for a Kalpana-One style habitat for the workers (see my post, designing a space habitat).

The approach I recommend is to capture an asteroid (see Asteroid Capture into Earth Orbit) and use its resources to produce the steel and other materials needed to construct and operate a constellation of SPS’s.

This approach has a relatively high up-front investment and results in a relatively low per-SPS cost. The project has many phases:

Research & Development
Capture a suitable asteroid into Earth orbit
Launch Mining & Manufacturing Tools
Launch Construction Shacks & Workers
Construct & Deploy the SPS(s)
Construct the Kalpana-One style Habitat(s)
Repeat 5-6 as long as asteroid resources remain

For the purposes of this post, I make several assumptions:

we have chosen the asteroid 99942 Apophis, which also locks us into a 2029 timeline (project start in 2027, launch capture mission in early 2028).
use of SpaceX’s Falcon 9 Heavy launch vehicle (announced with pricing, but not yet built, yet alone flown).
pricing in 2011 dollars which must be adjusted for inflation.
Worker launch costs initially average $24M/person, but in a 2031 timeframe human-rated transports will be built for the Falcon 9 Heavy (or eventually Falcon X Heavy) that can transport 30 to 100 people per launch into LEO at a price of $1,000,000 per ton (also per person).
I ignore in-space worker salaries (small compared to launch costs)
For income, I only consider Solar Power Satellites, ignoring tourism, the sales/rentals of housing and retail space, sales of propellants to outside parties, product placement, tie-ins, naming rights, or any other potential revenue sources.

RESEARCH & DEVELOPMENT

It may be an unreal oversimplification, but I will ignore the R&D costs for this project although they are large and unknown. I believe that NASA, the various governments, and the network of universities should bear this cost as part of their normal operations (supported by tuitions, taxes, and donations), although the more directed research will be borne by the corporations that will profit from the sales of related equipment and supplies. Known areas of research & development include:

Heavy lift launch vehicles
Space taxies / trucks (using ion thrusters to cheaply change orbits and to capture the asteroid)
Long-term life support (recycling & farming in space)
Zero Gravity Mining, Smelting, Refining, and Manufacturing (note need to recycle reagents and to capture and utilize bi-products such as CO2).
Manufacturing Solar Photovoltaic Panels from asteroid materials
High-efficiency Muilti-Gigawatt Microwave Transmitters / Receivers
Large-scale in-space construction techniques (of SPS and habitats) with limited resources

CAPTURE A SUITABLE ASTEROID

How to capture an asteroid is largely covered by my previous post, Asteroid Capture into Earth Orbit, and a future post will detail the components of the capture project, including a proposed project breakdown of the needed components, launches, delta-v budgets, and a project timeline.

The Asteroid Capture Project begins in 2027 with construction (in orbit) of a space tug. The tugship launch from LEO to intercept Apophis occurs in April of 2028, and the final Lunar slingshot of Apophis effecting capture into Earth orbit occurs 18 months later, in October of 2029. These dates are driven by orbital dynamics.

A simplified overview of the Apophis Capture Project (using current or near-term launch vehicles) is:

Launch tugship, fuel, solar panels to LEO: total 150 tons, needs 5 Falcon 9 Heavy launches ($500M); cost of tugship, etc. another $1.5B. This cost is lower than many space-based projects because of the extensive use of modular components assembled by humans in space(reducing the need for first-time perfection).
Launch in-orbit assembly crew: 1 @ $100M, probably another $1B for training, tools, supplies, support staff.
Launch mission crew & supplies: 1 @ $100M
Intercept mission uses ion thrusters and a lunar slingshot to enter Apophis intercept trajectory in April 2028.
2 months to intercept; 3 months of thrust to change Apophis orbit; 1 month of contingency; 6 months of coasting. After the slingshot around the Earth in April of 2029 there is another 6 months of coasting (with likely trajectory tweaking) before the final drop into Earth orbit via a Lunar slingshot in October, 2029. Capture Mission duration is a little over 18 months; with recycling of water & oxygen, 600 days of food & water & hydrogen (to recycle CO2) for a crew of 4 masses four tons; a similar mass is needed for the associated equipment (triply redundant).

Total capture cost: $3.2B (ignoring R&D and ground support costs).

LAUNCH MINING & MANUFACTURING TOOLS

This is a big unknown, in that we don’t yet know how to best do mining, smelting, refining, and manufacturing in space (microgravity, necessity to recycle & save everything) from asteroid resources. We can make good guesses, however. Also, the facilities should grow over time, but the initial launches should suffice for starting manufacturing, especially since we are largely launching tools to make tools. After the initial launches, most of the needed additional equipment will be manufactured in space. These launches would begin in 2029; I expect the tugship will be used to transport these components from LEO to the asteroid now in Highly Eccentric Earth Orbit.

Solar Power generator: 1 launch, $200M
Mining facility (ore movers, grinders, separators): 2 launches, $400M
Solar smelter, gas collection & refining, metal purification: 5 launches, $1B
Steel production: 5 launches, $1B
Rolling mill (girders, rods, sheet metal): 3 launches, $600M
Finished metal product plant (nuts, bolts, rivets, connectors, pipes, tanks, etc.): 2 launches, $400M
Silicon refinery, solar panel manufacturing (3 launches, $600M)
Slag processing, shaping, rock wool production, & slag handling (1 launch, $200M)

Total estimate is $4.4B for equipment and 22 launches, and this phase begins in 2029, ends in early 2030.

LAUNCH INITIAL WORKERS & THEIR CONSTRUCTION SHACKS

The initial workforce for all of the mining & manufacturing equipment, even assuming significant automation, is considerable. I estimate 36 workers, needing 6 launches using Falcon 9’s and Dragon X capsules (total $600M) just to get started. Each crew member will likely require a ton or more of life support equipment and supplies.

The Construction Shacks are the living quarters, recycling equipment, supplies, and solar panels for the initial mining and manufacturing workforce, intended to be buried beneath asteroid regolith for radiation and meteorite shielding (alternately regolith may be bagged and packed around the shacks). This will need to be repeated as the workforce grows (until a permanent habitat is at least partially completed).

The Falcon 9 payload faring may be equipped to house up to 12, with room for supplies and equipment. Three of these would provide adequate housing and first-year supplies for the initial 36 workers, at a cost of $600M bringing the total cost to $1.2B ($33M/person).

Subsequent workers initially have similar high launch and support costs, ramping down to $15M per-person as capacity grows to produce living quarters, water, and oxygen in space. When the interim habitat is ready and larger capacity people launchers (32 workers/launch) become available, per-worker launch costs should plummet to roughly $3M per person (in 2031), and as low as $1M per worker in subsequent years (with use of dedicated people-carrying spacecraft ferrying 100 workers into space per launch). Note that a 1 ton per worker mass allowance includes some essentials that cannot be easily fabricated in space, such as high-efficiency LEDs for the farms, some fertilizers, and medical supplies.

The workforce & construction shack launches could begin in late 2029.

This initial 36 worker contingent will be sufficient to prove the feasibility of mining, refining, and manufacturing in space, but will be inadequate to achieve sufficient volumes of production for a timely project completion.

A ramp up to 500 workers during 2030 should result in a steel production rate of roughly 100 tons per day, which in turn allows construction of the habitat pressure shell plus containers for the volatiles (oxygen, CO2, and H2O) in one year. At this point (an interim habitat consisting only of a spinning pressurized shell with partial radiation shielding), many of the workers can work without pressure suits, gravity prevents long-term health problems of zero-G living, and in-space production of food can begin.

Doubling the population and production annually allows the first SPS to be completed by the end of 2031 (when steel production is 200 tons per day, comparable to a small mill on Earth). 2032 should see 2 more SPS’s completed, and 2033 results in 4 more and completion of the habitat structure (with room for 8,000). By the end of 2033 the habitat capacity is reached, and the associated manufacturing facilities should be capable of building 8 SPS’s per year. Remember, it takes all of the slag associated with building the first 12 SPS’s to fully shield the habitat, which occurs during 2034. By the end of 2034, the first permanent habitat (8,000 person capacity) is complete, along with 15 Solar Power Satellites.

The total worker cost through completion of the first SPS and the habitat shell would be $15B (by the end of 2031, a total of 1,500 workers). Adding 2,000 more workers in 2032 and 4,000 more workers in 2033 would cost only another $6B.

This analysis has ignored the cost of salaries for space workers (and the cost of ground support). One reason to ignore the salaries is that they are insignificant compared to launch and equipment cost in the early years.

Another reason to ignore them is that portions of each “salary” may be offset: workers may be charged for rent (or purchase of a condo), for food, water, recycling, even oxygen. The cost of living is very high in space, and salaries should reflect that, but the net cost of a worker is difficult to estimate. Many of the readers of this blog would likely volunteer to work for little more than the right to permanently live in space and be a part of humanity’s spacefaring future – I know I would. Very few of the workers would view these orbiting factories and habitats as temporary jobs and expect to return to Earth in a few years, especially if they were afforded the opportunity to buy a home and raise a family in the habitat.

CONSTRUCT & DEPLOY THE SPS

The construction of a Solar Power satellite requires multiple components, most of which will need to be built in orbit. For more details, see Solar Power Satellite Design Considerations. The components are:

Solar Panels (from high-grade silicon, in thin sheets such as commonly manufactured today)
Steel structures to frame and aim the panels.
Steel structures and motors to maintain alignment of the panels with the sun, and the antenna with the target Earth station.
Microwave transmitting antenna
Microwave transmitter
Shield mass to protect the electronics from meteorite damage.
Fuel to insert the SPS into the target geosynchronous orbit

I expect that the motors and electronics (including the microwave transmitter) will be launched from Earth, for which I’ve budgeted $200M per SPS.

A considerable amount of fuel is needed to move each newly constructed SPS from the near-Lunar location of its birth and insert it into an appropriate geostationary orbit. The total delta-V needed is roughly 2 km/s, the total mass is 25,000 tons, and even using 5,000 ISP VASIMR ion thrusters, 1,000 tons of fuel is needed. Luckily, that is a tiny fraction of the 15,000 tons of oxygen produced as a by-product of the smelting of iron ore into steel for each SPS. Also luckily, we’ll have a lot of power available, so the time required for this orbit change is limited largely by the number of ion thrusters (and thus the fuel flow rate) we wish to dedicate to this task. We’ll have plenty of oxygen to spare, so our ion thrusters should be optimized for this most available rocket fuel.

Each SPS will require a matching ground receiving station consisting of a large (10+ kilometer) rectenna plus power conversion and distribution. These costs are only a guess, but I’d estimate that $1B each is more than enough. I have not included this portion of the per-SPS cost in my summary, as this cost would be born by the receiving local electric utility.

CONSTRUCT THE HABITAT

Another post details the Design of a minimum Kalpana-One style Habitat: a 100-meter radius cylinder, 130 meters wide, spinning at 3rpm for 1G along the outer rim, lined with 3 meters of slag which provides excellent shielding against radiation and meteorites.

The outer pressure shell is built using average strength (easily welded) steel plates nearly 1 inch thick, and masses approximately 28,000 tons. Completed first, once spun up it provides a shirt-sleeve environment with gravity, boosting the productivity and health of the workers.

Over time, blocks of slag are brought inside to line the exterior walls, and interior structures are built as housing, workspaces, and farmland. Most of the volume is left open to eventually become a 12 acre cylindrical park. The core will be available as a low-gravity industrial and research space. Agriculture space (primarily for crops) is more than 5.5 million square feet; residential space is over 2.5 million square feet, there is 1.5 million square feet of offices / light industrial and a million square feet of storage and overhead space. The total internal structures including the outer 15 meters along the endcaps and perhaps 6 stories of rooms lining the cylinder rim, plus a 40 meter diameter core structure, masses 126,000 tons (a generous allowance). This is less tonnage than an Oasis Class Cruise Ship (225,000 tons carrying 8,000 passengers and crew) yet much more spacious.

Power (6 kw/inhabitant or 50 megawatts total) is provided by solar panels lining the exterior surface of one endcap, plus a ring extending 100+ meters beyond the cylinder (effectively a 425-meter diameter solar panel array). Additional power needed for exterior factories (such as the smelter) is included in their structures and allowances. The spin axis of the habitat points to the sun, requiring a massive gyroscope at the center of the habitat to slowly precess the spin axis at one revolution per year.

Speaking of spin, it takes a lot of fuel and energy to spin up the habitat to 3rpm: about 1150 tons of fuel (oxygen) at an ISP of 5,000. Using 25 megawatts (half of the habitat’s available power), the spin up takes nearly 2 years. However, the empty shell (no shield mass) spins up very quickly; the majority of the energy is needed to maintain the spin as roughly a million tons of shield mass is gradually added to the habitat’s periphery.

Once complete, this habitat houses 8,000 workers / colonists, and provides all life-support needs. All of the steel (154,000 tons) and shield mass (1,600,000 tons of slag) are from the asteroid, along with the oxygen, water, and carbon needed for the life support system. The known components to be launched from Earth include the LED’s and other light sources for the farms and interior (see Lighting our Space Habitats), various electronics, seeds, and perhaps 50 kilograms of nitrogen (per inhabitant) needed as fertilizer.

There are no additional launch or equipment costs not included elsewhere (possibly excluding the ion thrusters needed for spin-up).

REPEAT

This project is an eight-year plan (5 years to the first SPS) culminating in the deployment of a permanent, self-sustaining habitat with a population of 8,000 and fifteen 5-gigawatt Solar Power Satellites in geostationary Earth orbit. By completion, the project will have consumed approximately 10% of Apophis, leaving 90% available to build additional habitats and Solar Power Satellites.

The capacity will be in place to build additional Solar Power Satellites at the rate of 8 per year, but note that demand is much higher: current global electric demand would need 400 five-gigawatt SPS’s to fill, and total projected energy demand might require more than 4,000 by 2050 (most energy is used for heating, generally by burning fossil fuels). Apophis alone has sufficient resources to build up to 150 Solar Power Satellites (while building 10 habitats accommodating 8,000 people each), but in the long run additional asteroids will be needed.

We should build additional habitats, including larger ones, as part of an ongoing project. We’ll likely need a “mining town” for each asteroid we capture, and an SPS construction / maintenance habitat just outside of geostationary orbit, and even a large habitat in low Earth orbit (as low as possible without serious atmospheric drag) as an Earth to LEO launch target and tourist destination. Good arguments can be made for additional habitats in various Lagrange points such as L5, and for transition orbits such as LEO to Geostationary, or to the Lagrange points. There may even be a 3:1 Lunar synchronous stable Earth orbit that visits L3, L4, and L5 in succession, 9.1 days apart – an ideal platform from which to host interplanetary missions, including to Mars.

SUMMARY

It all sounds time consuming and expensive: $22.8 Billion before that first SPS is operational. But remember, in 2032 that first SPS will generate $1.3B in cash flow (at a wholesale price of $0.03/kwh), in 2033 the 3 deployed SPS’s generate another $3.9B, in 2034 the 7 deployed SPS’s generate $9.1B, and subsequently the 15 SPS’s generate nearly $20B/year. The steel production rate is 800 tons per day, allowing 8 or more additional SPS’s to be built each year. The peak cash outlay is $25B with all investment repaid in 2035 – and huge net profits after that.

Even considering only that first SPS, the total cost is comparable to the $5 billion per gigawatt that my local power company may spend on a nuclear power plant, without any need for radioactive waste disposal or refueling, and without quite as much local objection to the installation.

Yes, I’ve been accused of being an optimist. Yes, it is likely to take longer than this project plan, due to unforeseen setbacks. Yes, I’ve ignored the cost of money in this analysis. I’ve even ignored the cost of bringing all these workers back to Earth (assuming they’d want to return). But even if it takes another year or two before breakeven, even if the costs might run 20% (or 100%) higher, even if you factor in the up-front R&D costs, even if you add a generous salary for every in-space worker plus free room & board, it is still a wildly profitable venture.

And did I mention that Apophis has enough raw materials to repeat this project another nine times, at a fraction of the cost each (and completely funded by free cash flow)?

Is there an entrepreneur listening that likes the sound of $200 Billion per year of free cash flow for a measly $30 billion investment? And with the bonus of earning a permanent place in the history books as the party responsible for bootstrapping humanity’s move into the Solar System?!

Solar Power Satellite Design Considerations

2011-01-29T18:59:00.001-05:00

The major considerations driving solar power satellite design decisions are:

location (geostationary, LEO, other)
energy delivery method to Earth
solar panel photovoltaic versus turbine generator (efficiency/cost tradeoff)
size of an SPS (dimensions, mass, power)

LOCATION

Most studies recommend a geostationary orbit for Solar Power Satellites. This choice simplifies designs, and is the only choice that can deliver continuous power from a single SPS – the others require a constellation of satellites with any given ground station receiving power from a sequence of satellites. The disadvantages are that a relatively large transmitting antenna is required, and it takes more energy to reach those geostationary orbits.

Another disadvantage is that it is inefficient to deliver power to high latitudes; multiple satellites with Molniya orbits are one possible alternative.

An SPS constellation in medium Earth orbit has been proposed, because of the lower cost to launch from Earth and the smaller size of the transmitting antenna. The disadvantages are that both the transmitting and receiving antennas may need to be dynamically aimed, plus the “dark” time due to passing through the Earth’s shadow is much greater, requiring still more satellites to deliver continuous power.

The remainder of this post will focus on geostationary locations, which have been studied more thoroughly.

MICROWAVE ENERGY DELIVERY TO EARTH

The minimum size of an SPS is driven by the size of the energy transmitter and the Earthside receiving station. While several alternatives have been considered, the best option appears to be beaming microwaves to Earth receiving stations from geosynchronous orbit. To achieve sufficiently narrow beams that arrive at sufficiently low energy densities (so as not to cook anything in their path), we’ll need a transmitting antenna one kilometer wide.

The receiving station is larger at 10 kilometers east-to-west and as long north-to-south as necessary to appear circular from the SPS (a 10 kilometer circle at the equator, a 10 by 15 kilometer oval at 30 degrees latitude, 10 by 20 kilometers at 45 degrees latitude, perhaps 10 by 30 kilometers at 60 degrees). Note that 60 degrees latitude is approximately the limit of feasibility due to both the size of the receiving array and the amount of atmosphere that must be traversed. Luckily, this supports serving the vast majority of the global population, excluding only the Artic regions, Alaska (U.S.A.), northern Canada, and the European Nordic countries and northern Russia. Note that St. Petersburg (Russia), Helsinki (Finland), Stockholm (Sweden), and Oslo (Norway) are near the limits of servable destinations.

An Earth-side energy density of 23 mW/cm² (chosen as safe for all life forms) equates to 5 gigawatts as a minimum power limit near the equator and proportionally more at higher latitudes. Building smaller SPS systems can be done, but the antenna arrays would not be smaller (or cheaper), and thus would be less cost-effective. Note that some sources suggest a minimum size of 4 gigawatts. In any event, at 2.45 Ghz (the highest frequency with negligible absorption by rain, snow, clouds, and people), a one-kilometer transmitter could not possibly focus higher intensities upon the Earth, making this a safe and non-military technology.

The likely technology for the receiving station is a rectenna array, a network of many simple wires with diodes. It can be deployed above cropland (and herds of cattle, even forests) with only minor loss of productivity of the farm. Receiver losses will be of the order of 10%, much less than typical long distance power transmission.

A side point: direct-to-home power transmission is perfectly feasible. A home rooftop rectenna could easily capture 5 or 10 kilowatts of power, several times the average household demand. The problem is all the power wasted between rooftops, including undesirable electric currents induced in most metals and wiring. But perhaps this is not a problem in a military environment, where an energy beam could be directed to the conflict zone, not as a weapon, but for providing electrical power wherever needed. This also has direct military applications: SPS powered drones could fly indefinitely.

HOW BIG IS A SOLAR POWER SATELLITE?

So how big is the SPS itself? That depends critically on the efficiency of solar energy capture and thus the technology used. There are two likely technologies: solar cells (photovoltaic) and solar dynamic (mirrors and gas or steam turbine powered generators). Both methods take advantage of the near-constant sunlight (only shadowed by the Earth for a few total hours near midnight twice a year, and never for more than 75 minutes at a time) – a net 99% availability. Also, the intensity of solar energy in space is greater than on the Earth’s surface due to the lack of air to absorb energy. About 950w/m² strikes the Earth’s surface at noon on the equator on a clear day, while in orbit the solar energy density is 1367w/m² all of the time.

Solar Photovoltaic versus Solar Dynamic

Solar cells vary hugely in cost and efficiency. Common cells convert about 10% of the incoming energy to electricity. But modern cells convert 20% (thin film) to 40% (optimized) of the incoming energy. Caltech claimed to achieve 85% in a highly experimental demonstration in March of 2010. We don’t know what technology will be the most cost-efficient. Note that 25% efficiency implies a 4km by 4km photovoltaic array would generate 5 gigawatts in orbit, although it would take a 4.25km square array to deliver 5 gigawatts to the Earth assuming an 80% efficiency in the transmitter / receiver.

Solar dynamic may be more efficient, as large, low-cost mirror arrays focus the sun’s heat on a boiler driving a turbine electric generator. The mirrors are relatively inexpensive, and the cost will be dominated by the need to remove the waste heat using large cooling arrays. But the efficiencies are quite high, typically 40% to 50% (potentially even higher, depending upon the fluid used). Ordinary steam turbines can achieve 40% efficiency. Hybrid designs with a gas turbine followed by a steam turbine can achieve 60% or higher efficiency. The problem with solar dynamic is that moving parts imply mechanical failures. These units would likely require a nearby crew for maintenance – something easily provided from a space-based habitat. Note that at 60% efficiency, a circular mirror of 2.8 km diameter (or a 2.5 km square array) is sufficient for a 5 gigawatt SPS.

Solar dynamic has other advantages: lightweight flexible mirrors (such as ordinary aluminum foil) are not significantly affected by radiation, ultraviolet light, or micrometeor punctures. Disadvantages include that the turbines and generators are heavy, high-tech components that may have to be launched from the Earth. Also, the working fluid in the gas/steam turbines may not be cheaply available. The only gas available in large quantities is oxygen, which is very corrosive to many metal surfaces, at least until we capture the resources of a live or extinct comet which is likely to contain enormous quantities of water and ammonia.

PHYSICAL SIZE OF A SOLAR POWER SATELLITE

Using assumptions listed above, the width of an SPS might range from 2.5km to 4.25km, or as large as 6.75km if we use the cheapest solar cell technologies. But 4.25km looks like a reasonable target. Note that at geosync orbital distances, these would be as visible as the larger planets, and easily resolved with binoculars. Once hundreds were in orbit, they would appear as an arc of lights to anyone who looked up on a clear night.

There is also a nearby 1.0km microwave transmitting antenna, visible using binoculars. One problem is that the solar cells must always point at the sun while the transmitting antenna must always point to the Earth side receiving station. Proposed solutions include:

use the same structure with phased array techniques to steer the beam (always pointed at the sun), difficult for certain orientations;
use separate structures with some connecting mechanism that rotates one or both arrays;
use a smaller integrated array of a 1km transmitter (always pointing to the Earth) backed by a (fixed) 1km photovoltaic array, and a separate large mirror to track the sun and focus its light on the back of the transmitter. While appealing in several respects, this does have its own problems: dissipating roughly 15kw of waste heat per square meter, which implies a blackbody temperature of 240^oC if there is no additional radiating surface (it couldn’t be a manned structure, and would have to cool off prior to maintenance). The mirror and the transceiver would have different orbits – one would require constant adjustments. Lastly, it would be difficult to focus sufficient light on the transceiver near local noon each day. But some clever engineer may find a solution to all these problems.

MASS OF A SOLAR POWER SATELLITE

Using modestly optimistic assumptions for solar photovoltaic panels, supporting structure, power collection, and for the microwave transmitter and its own antenna, I estimate a total mass of 25,000 tons for a five-gigawatt SPS. Early estimates were closer to five times higher, and some optimists currently estimate that thin film panels would weigh one-fifth as much, although a supporting structure and the transmitter must also be considered. Note that if the solar panel array is 4km on a side, then 1.0 kg/m² of panels, structure, and wiring results in a total mass of 16,000 tons, leaving the remainder of my mass allowance for the transmitter, its antenna, and other support structures.

A 1.0kg/m² mass allowance solar cells, wiring, and structure seems like a significant challenge, requiring a substrate similar to a sheet of paper in thickness. Note that a silicon wafer sliced 1.0mm thick weighs 2.3kg/m². However, the typical thickness of photovoltaic silicon wafers today is only a tenth that, and thus weighs 0.23kg/m2, leaving adequate allowance for structural components and wiring.

When using the resources of an asteroid to build the Solar Power Satellite, the mass of the photovoltaic panels is only a minor concern, as there is more than enough silicon and iron in even a small asteroid to build them as crudely as desired. Indeed, using a convenient asteroid allows the construction of large and inefficient but presumably simple and reliable solar power satellites. The final technology choice may be one of minimum labor costs or total time-to-market. Those tradeoffs are not simple, because using a less efficient technology (that is simpler to produce) implies a significantly larger structure with more materials and thus more time and effort to build.

But by using an asteroid for raw materials, we at least have choices to make beyond “is it even feasible?” Launch costs of people and tools to bootstrap the process will be high enough as it is, but having the cheap and convenient asteroidal resources in orbit where we need them gives us the flexibility to try not just one approach, but several approaches and learn which is the best way to deliver clean and cheap energy to the inhabitants of Earth.

Space-Based Solar Power

2011-01-23T10:08:00.001-05:00

Many people have written pages, papers, even entire books on the subject of Space Based Solar Power. Certainly many of the authors are better qualified than I am. What my posts add to the mix is the cost reduction and simplicity gained by using an asteroid captured into Earth orbit for the bulk of the materials.

Also, some of my sources are more recent than many older papers – which makes a huge difference. For example, my earlier posts used a figure of 125,000 tons for a 4 gigawatt SPS, based upon references quoting 20,000 tons per gigawatt, plus structure and the transmitter. But more recent sources propose a very lightweight design requiring only 1,000 tons per gigawatt – a 20-fold reduction. For these posts, I’ll be using an intermediate figure of 5,000 tons per gigawatt, or a total of 25,000 tons for a 5 gigawatt SPS (measuring 4 km on a side).

Even with current high launch costs, at least one company believes they can build a cost-effective SBSP system using all Earth-sourced materials. I don’t see how, since fifty to a hundred or more 100-ton payload launches would be required. But the people with their money on the line have put more thought into justifying the ROI, and I wish them well.

More commonly, pundits believe that Lunar materials (typically using a launch-rail system to lower the cost of launching materials from the Moon) might reduce the total cost to an acceptable level for as few as 50 to 100 SPSs (to amortize the costs of landing a great deal of equipment and people on the Moon).

Asteroidal resources are much more readily available, and several sources have proposed robotic mining missions to various asteroids (chosen for a low net delta-V, especially for returning material to Earth orbit). Some proposals return raw material to Earth orbit for processing; others return materials processed to some degree (such as iron). Robotic missions are often assumed to eliminate life-support and radiation shielding costs.

Note that a 100-meter radius Kalpana One style habitat (housing and feeding up to 8,000 residents) can be built from a single 120-meter asteroid, along with 12 five-gigawatt Solar Power Satellites, using the slag from iron smelting as radiation shielding.

My proposal (see Capturing an Asteroid) is to use gravitational slingshot maneuvers (around the Earth, the Moon, or even Mars or Venus when appropriate) to capture one or more asteroids into Highly Eccentric Earth Orbit (HEEO), then to launch the tools needed to mine the asteroid, smelt it into valuable materials, and build the SPS network in orbit. Of course, this is simply a logical extension of the proposals to return asteroid raw materials to Earth orbit. I propose to send the whole asteroid (which we can do given the extraordinary special circumstance of an existing close approach of an asteroid).

This approach requires large numbers of people in space, because people are good at problem solving. Using robotic approaches requires that the engineers anticipate all possible contingencies, and, speaking as an experienced computer programmer, I absolutely guarantee that we will never succeed at anticipating every possibility.

But people are resourceful, and their ingenuity will solve all of the little problems, and likely the big ones that crop up, as well. The number of people needed is huge, because each SPS is itself huge (kilometers wide), and there is a lot of work required. We’ll need to smelt ore into steel at impressive rates (but typical of a foundry on Earth). We’ll need to form that steel into plates, girders, pipes, tanks, cables, etc.. We’ll also need tables, and chairs, and sinks, and toilets. It’s expensive to bring those things up from Earth.

We’ll need to use part of that steel (and much of the slag) to build habitats for space workers (see Designing a Space Habitat). We’ll need to produce magnesium for mirrors (assuming turbine-driven electric generators) or silicon for solar voltaic cells (or both – we won’t know what is best until we try). We’ll need to weld or bolt all the pieces together into immense structures, and then maintain them (because parts fail, regardless of how well-built they are). We are likely speaking of thousands of people to build that first SPS, and thousands more to build and maintain a network of them.

Carbonaceous chondrite asteroids and extinct comets certainly contain everything needed. These comprise at least 75% of all asteroids, although they are relatively rare among Earth-crossing ones. However, any undifferentiated asteroid (such as ordinary chondrites) should suffice. All of these contain vast quantities of iron, oxygen, and magnesium. Most asteroids will contain small but significant quantities of carbon and hydrogen, easily extracted by simple heating. The asteroids to avoid are those from parent bodies that melted and differentiated, since that would isolate most metals into an iron core, and deplete the volatiles, leaving ore as poor and dry as moon rocks.

HOWEVER, there are significant ground-based costs to consider as well. In addition to building an SPS with a microwave transmitter to deliver power to an Earth station, we must build that ground station, which (in principle) is easy and low-tech, but is still large (and thus expensive, partly because of land-use costs), plus we must build the power distribution network to get the electricity to the consumer. I do not have a good handle on this cost, which I am certain will vary tremendously from site to site, as it should be much cheaper where land is cheap (and power is not needed), and will be much more expensive close to major cities where the power is needed but land is expensive plus there is always resistance to putting the receiving rectenna in our back yards.

Note that the receiver may typically require an oval roughly three miles wide and six long, but it is sparse and may be placed over a farm with little impact on crops or livestock below. It may also be place in a forest just above the treetops, where it would not even be all that visible. As a very rough estimate, I will assume that the ground-side costs will equal the in-orbit costs per SPS, although I will also plan that all of the up-front capital costs are for the SPS itself (a simplistic approach that ignores the cost of lawyers and politicians).

My next post will discuss specific design considerations for a Solar Power Satellite.

Economics of Solar Power Satellites

2011-01-21T10:52:00.001-05:00

Reading my local paper yesterday, I learned that the cost of building new, modern, nuclear power plants was much higher than I had thought. The Jacksonville Electric Authority (JEA) is considering a 20% share of a new 2 Gigawatt plant – at a cost of $2 Billion. The total cost of the plant is $10 Billion – or $5 Billion per gigawatt.

This seems horribly expensive, but the resulting steady, cheap, zero-carbon electricity apparently makes the capital investment worth while.

The cost is indeed high, which is good news for Space Based Solar Power: it may be possible to profitably launch the components directly from Earth to build a Solar Power Satellite (just barely).

But as I have argued in previous posts, there is a much less expensive way to build Solar Power Satellites: build them in orbit using asteroids which provide all the raw materials we need (just add tools and workers).

As a side benefit of great importance to most of the readers of this blog, my plan requires the building of permanent orbiting space habitats, self-sufficient, rotating for gravity, and using the slag from iron smelting as radiation shielding – a topic I’ve discussed before.

My next several posts will discuss various aspects of Space Based Solar Power built using asteroid materials, from some high-level design considerations to construction techniques and ultimately to revenue generation and return on investment.

I am more convinced than ever that we can expand humanity into space using ground-based profit motive, with benefits of lower energy costs, near-zero carbon emissions, and, did I mention, HUGE PROFITS?

Asteroid Capture into Earth Orbit

2010-06-03T20:14:00.001-04:00

(This long post is the presentation I delivered at the International Space Development Conference in Chicago on May 30, 2010. Links to additional information have been added, and overhead slides have been deleted.)

Why capture an asteroid? The main reason is to gain convenient access to its resources. Even a relatively resource-poor low-iron, low-metal LL chondrite contains 20% iron, significant quantities of water and other volatiles in the form of minerals such as clays, and oxygen to burn. And the best place to have those resources is in Earth orbit where they will have the greatest value. I will show how an investment of perhaps $20B will result in a trillion dollars worth of resources – a fifty-fold gain, with tremendous benefits for all of humanity humanity.

For example, the asteroid Apophis (likely one of those LL chondrites) contains enough materials to construct about 125 five-gigawatt solar power satellites at 25,000 tons of steel each, plus Kalpana One style habitats for 100,000 people. The slag remaining after iron is smelted out of asteroid ore works nicely as the radiation shield, of which we’ll need 200 tons per person. The oxygen freed from iron compounds during reduction (1 ton of oxygen per 3 tons of iron) amounts to well over a million tons more than is needed for our habitats, and I expect we’ll use that oxygen as fuel mass for ion thrusters to move the habitats and solar power satellites into their chosen orbits.

Kalpana One style habitats are basically stubby cylinders spinning for gravity, with outer hulls containing 10 tons of radiation shield per square meter to provide protection against radiation and meteoroids similar to what we have on the surface of the Earth (which, not coincidentally has 10 tons of atmosphere above every square meter).

Of course, a space habitat providing food, water, oxygen, fuel, construction supplies, gravity, radiation shielding, and skilled human workers and situated above much of the Earth’s gravity well is an ideal platform from which to continue the exploration and exploitation of space.

And we should not forget that placing an asteroid into a stable Earth orbit prevents it from colliding with the Earth. In the long run, I believe that humanity will view Earth-crossing, potentially hazardous asteroids as low-hanging fruit, and each future discovery of an asteroid on a possible collision path will be followed by a gold-rush style race culminating in another new moon for our planet. Of course, each of these new moons will be somewhat temporary, as we convert its resources into more and larger habitats, solar power satellites, and other, perhaps undreamed of tools for the advancement and protection of humanity.

So, how do we capture an asteroid? Even a tiny one masses millions of tons, and we don’t yet have the technologies to manhandle them and put them wherever we want. Luckily, we don’t have to. When a spaceship or asteroid passes close to a planet or large moon, its orbit is changed, sometimes dramatically.

In principle, a slingshot around the Earth can impart a delta-V of up to 60 km/s to an asteroid in orbit around the Sun, although in practice the limits are a small fraction of this. More importantly, very small changes in the position or timing of an existing close approach are enormously magnified.

If we can adjust the asteroid’s orbit such that it makes a subsequent close approach to the Moon with a relatively low velocity, the resulting slingshot can drop that asteroid into a highly eccentric Earth orbit. The Moon can (in principle) remove up to 2 km/s of velocity relative to the Earth (although less is easier). Note that dropping the velocity of an asteroid to about .25 km/s (tangential) near the Moon’s orbit would result in an orbital period of about 9 days with perigee inside the geostationary orbits.

Let’s consider a specific example. The asteroid Apophis will approach Earth to within 30,000 kilometers on April 13, 2029, significantly inside the orbits of our geostationary satellites. If we do nothing, the Earth’s gravity will slingshot Apophis into a new orbit as it deflects it by about 28 degrees and boosts its velocity by 2.66 km/s. The result of this is that Apophis changes from a 0.89 year period Aten class asteroid orbiting mostly inside the Earth’s orbit to an Apollo class asteroid with a 1.167 year period and an orbit mostly outside of the Earth’s. I should point out that we don’t yet know with any degree of certainty exactly what the resulting orbit will be, because tiny changes in the position of closest approach have a huge impact on the resulting orbit. The period I’m quoting here corresponds to the keyhole that targets an Earth impact in 2036.

My main point is that delaying Apophis’ arrival at the Earth’s orbit by changing its velocity by only 7.5 cm/s for six months results in a 1.4 km/s reduction in delta-V - a velocity gain of a factor of 20,000. I chose that particular slingshot because it results in a semi-major axis of 1 au, with a period of 1 year (and somewhat ahead of the Earth in its orbit). I used a program named GravitySimulator by Tony Dunn to model several Apophis orbit variations, and simultaneously to gain a true appreciation of the art and genius needed to find useful orbits.

The Tisserand criterion indicates that it’s possible to change Apophis’ eccentricity to zero at the same time, although that would result in an inclination of about 10.5 degrees. In any case, what we really want is not a near-Earth orbit, but rather a subsequent slingshot around the Moon to remove excess velocity and drop the asteroid into a true Earth orbit. That may require some finesse and multiple slingshots, but I’m confident it can be done. Look at the success of Cassini and Messenger and all the other missions that have relied on gravity assist slingshots to achieve what once was considered impossible for our current technology.

We still need to give Apophis that 7.5 cm/s nudge. I don’t suggest abrupt changes from nuclear bombs or high-velocity impacts, partly because we need finesse to fine-tune the orbit, and that’s best done by the equivalent of titration. We need a tugship, a long-mission, highly fuel-efficient spacecraft to gradually move the asteroid into a new orbit.

Robotic missions may make a lot of sense in the future, because asteroid orbit changes are necessarily long-term missions. But until we figure out how to do it from actual experience, I think the ingenuity of real humans is needed to figure out what really works, out there in space, on the job. But manned missions have problems, too, largely revolving around the life support needs of fragile humans who need oxygen, water, and food to survive.

Ion thrusters such as VASIMR engines are likely the best choice to apply delta-V, as their high exhaust velocities reduce the total fuel mass needed, and they should be able to achieve sufficiently high reliability.

Of course, we need to push or pull the asteroid, which isn’t simple, partly because they are rotating, undoubtedly along an inconvenient axis. And they have enormous angular momentum which we can’t simply cancel. This means we’ll either have to dock – not land – at an appropriate location and thrust a fraction of the time, or use a gravity tractor approach which might limit us to lower thrusts and longer missions.

In addition, ion thrusters take copious amounts of energy. 25 megawatts can be generated by a 300 by 300 meter solar array, or by a single compact nuclear module available commercially. We do have a lot of experience with high-power nuclear modules in submarines and aircraft carriers, so that’s an option I personally lean toward, but politics may dictate a less proven approach.

Given an appropriate power supply, we still need enough time and fuel to move an asteroid.

So how much fuel do we need? As a first approximation, we can pick a specific keyhole, which targets a change in position at a future time. From the mission lead time, we easily compute the needed asteroid delta-V, and conservation of momentum allows us to compute the needed momentum change - the product of fuel mass times exhaust velocity. The asteroid’s mass and the needed delta-S (for this example) are givens, but we can choose to some extent our mission time.

Note that doubling the exhaust velocity quadruples the needed energy; 100 times the energy is needed for 10x velocity.

Let’s look at our Apophis example. That 200 second delay over a six month mission requires a fuel mass that varies by a factor of ten depending upon the exhaust velocity. With a lot of energy, we don’t need much fuel at all, barely 4 tons. With a specific impulse of 5,000, we only need 41 tons. These numbers are all well within our technological capabilities. Of course, additional fuel will be needed to deliver the tugship and its load of fuel to the asteroid, but again, the numbers are within our capabilities. We can do this!

But it seems that nothing is ever simple. Part of the problem is that we don’t really know much about asteroids. Many of them appear to be rubble piles, and in some cases these spin so rapidly that their shape is constrained by their spin, yielding flying-saucer shapes. Others are contact binaries which might be exceptionally awkward to manipulate. We have more options with solid bodies, but we can’t plan on that.

So how do we apply thrust? Two ways come to mind, dock and push, or use a gravity tractor to pull. Gravity tractors can only apply tiny amounts of thrust, but that might work best, especially on longer missions. It would also help to dangle heavier components such as nuclear reactors and fuel as close as possible to the asteroid, with the thrusters some distance away so they can aim off to the side without much loss of thrust efficiency.

There are other complications. As I mentioned before, gravity assists are hugely complex computations and the solutions are driven as much by creativity and imagination as by brute force calculations. There are many potential asteroid candidates, potentially multiple bodies to slingshot past, and multiple slingshots may be needed, as with the Cassini and Messenger missions.

At this point we don’t know enough about any of the potentially capturable asteroids, especially regarding their orbital parameters. Position uncertainties for most potential impacts for objects in the Potentially Hazardous Object database are in the tens of thousands of Earth radii once we go out twenty or more years. The uncertainties are not just due to the usual suspects of position and velocity, because things like albedo and asteroid spin have significant impacts over long periods. We would certainly need to know the true present course of an asteroid before undertaking any deflection efforts, accurately enough to eliminate any reasonable near-term possibility of an Earth impact. However, I believe that any deflection mission with a significant net reduction in impact probability over the next hundred (or thousand) years may be acceptable.

We’ll also need to address problems of mining, refining, and manufacturing in zero-gravity which may require entirely novel approaches. This is another area where human ingenuity will be vital, as I don’t think we’ll know what the problems and solutions are until we try something that doesn’t work the first time.

The last complication I’ll mention is that this is largely a bootstrap effort, with most of the costs up-front and the benefits and profits significantly in the future. But I’m optimistic, and I believe that an investment of as little as $20 billion, as described in The Economics of Life In Space, will result in annual revenue of about 1.3 billion dollars (wholesale electricity at $0.03/kwh) for each of the 125 SPSs we could build from Apophis. After building the first few solar power satellites, the revenue stream becomes self-sustaining with no additional investment required, although the population and infrastructure in space would continue to grow.

Lets discuss some of the selection criteria for choosing asteroids for potential capture into Earth orbit.

The most important consideration is simply the proximity of an asteroid’s orbit to a useful keyhole through which the orbital engineers can design a capture mission in a reasonable timeframe.

The second consideration is the size of the asteroid. Bigger is not better when a 1 kilometer asteroid masses fifty times as much as Apophis, and thus requires a fifty-fold increase in the product of mission time and fuel mass. On the other end, a small 120 meter LL asteroid massing 2 million tons (and relatively poor in useful metals and volatiles) still has sufficient materials to build a single small Kalpana style habitat for 8,000 colonists plus twelve 5-gigawatt SPSs, and requires one tenth the fuel (all else being equal). Thus I view 120 meters as the smallest asteroid worthy of capture, since it is barely large enough to build a permanent habitat rotating at 3rpm for Earth-normal gravity and with adequate radiation and meteoroid shielding. We will need at least that many miners, steel-workers, welders, SPS construction workers, and support personnel such as farmers to build the infrastructure and solar power satellites.

Another consideration is the V-infinity of the asteroid, because slower asteroids are easier to move a distance large enough to make a significant difference in the slingshot, and less asteroid delta-V will be needed.

The potential magnitude of a gravity assist is also constrained by how close to the center of the Earth the asteroid passes – and I think it’s important to keep it out of the lithosphere. Worse, for a rubble pile we don’t want to pass closer than the Roche limit or the asteroid may be torn apart by tidal effects, much as Jupiter’s tide tore the comet Shoemaker-Levy into 20 fragments. The actual Roche limit depends upon density, but is likely to be of the order of 20,000 kilometers for a rubble pile asteroid near the Earth, and perhaps 5,000 kilometers for the Moon.

One might think that the composition of an asteroid would be the number 1 criteria, but in reality most asteroids should be quite valuable. Of course, a common carbonaceous chondrite might contain 25% nickel-iron mostly in the form of metal grains, 10% or more water, and several percent carbon plus everything else needed for life in space. But even a lowly LL chondrite will work.

The last consideration here is the opportunities for intercept missions. We need to modify an asteroids orbit when it is easy, some months or even years before the targeted close approach. This is difficult for a high-inclination long-period asteroid because it might only approach closely enough to the Earth for low-delta-V intercept missions once every ten or a hundred years. But an asteroid with a two-year period might present suitable launch windows every two years. Also, for asteroids with low inclinations, there may be two launch windows in a year as the asteroid passes inside and then outside the Earth’s orbit.

This table presents some possible candidates as of mid May. Some of these will be eliminated by further refinement of their orbital parameters, while others can likely be added as additional asteroids are discovered, or as orbits are corrected for known ones.

The entries on this table were gleaned from the Near Earth Object Close Approach database. Note that the various tables, databases, and lists at the NASA web site are inconsistent, sometimes even on the same page. For example, the orbit visualization tool often has significantly different closest approaches than the “close approach” data on the same page.

A side note: Many asteroids have only been observed over a few days, resulting in large uncertainties in their orbital parameters. The shapes, diameters, and masses of most asteroids are estimated, not known. Diameters are estimated from an asteroid’s brightness, distance, and albedo. But we can’t measure the actual albedo, and observations at multiple wavelengths are used to judge the asteroid class, and from that a typical reflectivity, and from that a formula results in an estimate of the diameter, and assuming an average density, we calculate the mass. This process has very large error bars. In April, radar imaging resolved the asteroid YU55. Previous estimates were that it’s diameter was 140 meters and its mass 4 million tons. The actual measurement revealed a diameter of 400 meters and an estimated mass of 87 million tons, a 20x mass increase.

Lets consider these asteroids.

Apophis is fairly well characterized and has a very close approach on 13-Apr-2029, although it may not be an LL chondrite after all, and may therefore have a different albedo, diameter (currently 270m), and mass (currently 27 Mt - million tons). As a candidate for Earth-orbit capture, it has the advantages of passing quite close (4.6 Earth radii), and relatively slowly (V-infinity of 5.87 km/s), plus a launch window occurs each April 13^th near the close approaches and is thus suitable for a one-year mission. Missions to improve our knowledge can be launched in 2013 and 2021.

2007 RY19 is noted as having possible very close approaches in some databases, but not in others, and the error bars are very large. The best opportunity may be 03-Dec-2024. Its mass (1.8Mt) makes it easy to move, and intercept missions can be launched every 7 years or so.

2001 WN5 is a bit on the large side at 646 Mt, but it will pass about halfway between the Earth and Moon in 26-Jun-2028, which may offer an opportunity to adjust its subsequent orbit that we shouldn’t pass up, even if the actual capture couldn’t happen for a decade or two more. This asteroid is large enough to build thousands of SPSs and habitats for at least 2 million people.

At 87 megatons, 2005 YU55 is three times as massive as Apophis, and approaches Earth, Venus, and Mars, giving multiple possibilities for gravity assists. Next year it will pass about 20% closer than the Moon’s orbit, but it won’t be that close again for quite a while (depending upon its new orbit after the Earth slingshot). In its present orbit, it makes frequent approaches, about every 5 years.

2006 WB is a small asteroid that won’t pass very closely (nearly 2.5 lunar distances) on 26-Nov-2024, but it is small, and we can possibly adjust its orbit for subsequent passes. Note that its mass is poorly constrained, with different databases estimating its mass differently by a factor of four, from 0.5 Mt to 3.0 Mt.

1994 WR12 also approaches Mercury and passes Earth every 2 years in a nearly 3:2 synchronous orbit. Its next close approach is on 26-Nov-2021, and it has a perfect size at 2 megatons (120 meter diameter) making this an early practice possibility for changing an asteroid orbit. It doesn’t pass very closely at all, however, coming no closer in 2021 than 8 times the Moon’s distance.

I’d like to point out that every one of these asteroids were placed into their current orbits by a slingshot around the Earth, a fact clear at a glance at the orbital simulation on the NASA web site. One of the principles of orbital mechanics is that an orbiting body (in a 2-body system) will always return to the location and velocity vector of its last orbit change. Ignoring hyperbolic orbits, one near Earth pass means more, until the body collides with the Earth or is deflected away by another planet.

A legitimate question to ask is, will NASA undertake an effort such as capturing an asteroid into Earth orbit? Personally, I think it’s unlikely, because (at least as I have envisioned it) this is a commercial endeavor. Certainly NASA would not build solar power satellites, although we can task NASA with related aspects of human habitation in space, including habitat design, launch vehicles and tugships, farming, space operations, and other research projects that advance humanity into the Solar System. We might even get NASA to capture an asteroid into Earth orbit as one way to avoid a future Earth impact. I strongly encourage this, as NASA is an excellent organization to make sure the orbital capture is done right (if expensively), and then NASA could sell the exploitation rights to private enterprise and recoup all mission expenses.

China does not face the same political constraints and the Chinese government could easily choose to capture an asteroid and build habitats and solar power satellites.

The United Arab Emirates certainly has the funds to capture an asteroid and build a fleet of solar power satellites. And actually, I can’t envision a more appropriate use for the oil wealth they’ve accumulated. While they haven’t demonstrated the technologies to execute such a mission themselves, they could certainly fund it, buying themselves the resources to build that fleet of solar power satellites, and converting the dwindling stream of oil revenue into a growing stream of solar energy revenue.

Capturing and exploiting an asteroid such as Apophis can be done by private enterprise. I estimated the required investment as about $20 billion, which is certainly within the capabilities of the largest companies. And the prospect of a revenue stream of $150 billion per year should excite their CFOs.

Ignoring the profit motive for a moment, we should also consider that there are other possible reasons to invest in space habitats, specifically: to promote a way of life. There are many churches with the capacity to fund this effort, yielding a platform in the heavens, and a starting point to go forth and multiply. Certainly the resources available in the asteroids and comets dwarf to insignificance the Earth’s resources, so in the long term, the only thing that counts is that move into space.

And whether NASA, China, the UAE, private enterprise, or even some other organization steps forward to undertake this mission, capturing an asteroid is an incredible prize, as is the building of a the first large permanent colony in space -- accomplishments which will permanently record its founders in the history books.

Continued research tops the list of the several logical next steps we should take. NASA is ideally suited for several of these, and the continuing search for potentially hazardous objects identifies the same candidate asteroids as a search for potentially captureable ones. We need much better knowledge of their orbits, size, and composition; we need to explore slingshot opportunities; and we need to seriously advance our ability to move permanently into space via closed-loop recycling of everything.

We also need to address several legal issues, which pose a serious problem for Western civilization private enterprise. Key among this is the right to own and exploit objects in space. If a person or company does not have the right to exploit space-based resources, they can have no incentive to acquire them, and the future of humanity in space is effectively dead.

We must also address the liability of moving asteroids. Certainly this should be done with the utmost care and intense oversight tempered with some sense of practicality. For example, the example adjustment to Apophis orbit that I propose here appears to pass through the 2036 impact keyhole. Does that mean we must move the orbit out and around that keyhole, or simply that we use reliable, even redundant systems, and closely monitor to track the potential need for additional intervention? I’m afraid that science and logic may have little to do with the outcome of that discussion.

Someone needs to design and build a tugship using thruster and power technologies available in an appropriate timeframe. I think the biggest challenge here might be in supporting deep-space, long-term missions with the human crews I think are necessary to get the job done.

Lastly, we should refine the cost estimates for space based solar power from in-orbit asteroid resources and using a variety of technologies, although this is certainly a commercial endeavor.

The bottom line is that we CAN capture asteroids into Earth orbit, thanks to the amplification of delta-V due to gravitational slingshots.

There are several candidate asteroids today, and there will be more tomorrow. Also, I did not look for opportunities where the asteroid close approach was to Venus, or Mars, or Mercury (let along Jupiter), and there is every chance that many more good candidates exist, although longer missions would be required.

Lastly, we should never forget that capturing a potentially hazardous asteroid converts a dangerous threat into a resource of immense value.

My personal web page, www.StephenDCovey.com, gives too much information on my background and other ventures. But it also contains link called “Project Apophis” which very briefly summarizes this presentation, and concludes with a call to action via a link to the Office of the Whitehouse.

President Obama needs a grand goal for NASA and the nation in the next decades, one comparable to Kennedy’s “We choose to go to the moon in this decade.” I believe that capturing Apophis into Earth orbit is such a grand goal, with benefits to global energy and warming (via those solar power satellites), and to space exploration, and to permanent, self-sustaining habitats in space. And it removes a threat to the Earth.

If you agree that we need a space-faring humanity and that exploiting asteroids is key, if you agree that sending cheap solar energy to Earth simultaneously helps humanity and reduces global warming, and if you agree that we should act to prevent asteroid impacts on the Earth, then please share the word. Follow that link and tell President Obama that he holds the key to the future of humanity in space, that capturing Apophis is feasible, affordable, solves many problems in a single step, and is a Grand Goal worthy of his – and this nation’s – focus. Thank you.

The Economics of Life In Space

2010-03-13T14:49:00.001-05:00

For mankind to move into Space, it must be

Affordable in the short term
Profitable in the mid term
Self-sustaining in the long term

Each of these should be analyzed in more detail, even if they are self-evident to the optimists among us. Even the definition of short, mid, and long term are subject to discussion, but for these purposes the points above are self-defining.

The long term will begin when Earthbound civilization is no longer necessary for a space faring humanity. By not necessary, I don’t mean not useful: I expect that the cradle of mankind will always be an important part of humanity’s heritage. But at some point the continued expansion of humanity will no longer depend upon Earth resources. This has happened to every expansion of humanity (or a branch of civilization) at some point or another. For example, when Europeans colonized the Americas, the new territories may have initially profited by sending goods to the home country and depended upon tools and technologies created there, but eventually the continued expansion of the frontier no longer depended upon the Motherland. This may take longer (perhaps much longer) in space than on Earth, because the environment is hostile, a high level of technology is needed to survive there, and technological civilizations are complex. It may take tens of thousands of people living in space, or it may take tens of millions to replicate all of our technology. But it will happen.

The mid term will be the period when Earth profits from investments in space, and in some sense this will be a Golden Age of immense profits, rapid growth, unbridled enthusiasm and optimism. Many people have proposed many different potential sources of profit, but two stand out: tourism and Solar Power Satellites (SPSs).

Space Tourism is perhaps an indirect Earth profit generator. As long as launch costs are high (even as cheap as $500/pound), it will only be affordable by the wealthy. But most of the expenses are Earth-bound, and every million dollars spent on Space Tourism will contribute perhaps $2.5M to the Earth’s economy, supporting 25 to 50 families on Earth. Remember, you can’t spend money in space; every dollar spent on the space program is ultimately spent on Earth, and will continue to be until a space civilization can thrive on its own.

Space-Based Solar Power (SBSP) would directly benefit civilization on Earth, in multiple ways. Not only through stable, low-cost, zero pollution electric power, but also since the construction of Solar Power Satellites and the construction of Earth receiving stations would stimulate the Earth’s economy. Note that SBSP can provide cheap power to remote areas, including many of the poorest nations on Earth. Note that, as with space tourism, every dollar spent on SBSP (both construction and operation) is a dollar spent on Earth. The fact that a large-scale SBSP network would be enormously profitable for some corporations or nations in no way reduces its value to the Earth’s economy. And low-cost reliable power directly contributes to the wealth of the recipient. In a sense, reducing the use of fossil fuels (and the resulting global warming) is only an indirect benefit of SBSP.

Also note that SBSP would be expensive to build and launch from Earth; it will likely be affordable only when we can use space-based resources to build Solar Power Satellites (see my post, Capturing Apophis). But once built, Earth’s civilization benefits for the indefinite future.

The short term is the period – however long – when Earthbound civilization must invest in space. This includes the period when we are beginning to build a network of Solar Power Satellites, or space habitats for living, or space hotels for tourism. While any long-term space-based habitat is likely to produce its own power, food, water, and oxygen (recycling wastes in a closed cycle), most other needs must be met using tools and technologies imported from Earth, including LED’s for lighting the farms, computers, communication equipment, high-technology space suits, VASIMR rocket motors, vitamins, pharmaceuticals, medical equipment. The list is endless, although the relative need and value tails off rather quickly.

More importantly, the Short Term is the period while the costs of launching people, tools, and bootstrap resources into space exceed the profit derived from space-based enterprises, primarily SBSP. But the cost of bootstrapping a space-based civilization is an investment, pure and simple, yielding enormous profits for those clever and resourceful enough to make that investment.

The revenue from a single SPS is of the order of $1 Billion per year, suggesting that an investment of even $100 Billion to build and deploy a hundred SPS’s would be wildly profitable. Yet it would cost a fraction of that to capture an asteroid such as Apophis into Earth orbit, and to launch sufficient people and tools to turn that asteroid into a habitat and a factory to build Solar Power Satellites. Note that Apophis is too small to build more than about a dozen SPSs (assuming half of its mass is reserved for habitats). Yet it is more than large enough to bootstrap the process and support the ongoing space-based resources needed to capture additional asteroids to build thousands of SPSs and habitats for millions of people.

Let’s estimate some numbers:

$2 Billion: Commercialize the technologies to capture an asteroid (large-scale VASIMR, long-duration space flight)
$2 Billion: Launch the capture equipment and team. This will result in the capture of an asteroid such as Apophis into a highly-eccentric Earth orbit after a period of a year or two.
$2 Billion: Develop the processes and tools needed to mine, smelt, and process asteroid material into steel, oxygen, and hopefully CO2 and water. Other valuable materials are a bi-product. There are many unknowns, including the raw materials themselves, and zero-gravity smelting, and recycling of effluent gases such as carbon dioxide. Nothing should be vented / wasted.
$2 Billion: Launch the solar smelters, mining equipment, and tools to process iron ore into steel plates, girders, cables, etc.. Part of this is launching a small fleet of VASIMR tugs, fueled by excess oxygen from the smelters and using solar power for energy, to boost cargo and people from LEO to the HEEO of the captured asteroid. To a degree, this is launching the tools to build the tools to build the tools….
$2 Billion: Launch the people and habitat resources (LED lights for farms, solar panels for power, initial supplies of oxygen, food, and water, pumps and recycling equipment, ….)

Okay, so I used nice round numbers to get the total cost around $10 Billion. It may even be accurate to within a factor of two. In reality, I’d expect on-going costs of continuing launches of additional people and resources, perhaps $2 Billion per year for the 5 years I expect it would take to build the infrastructure and that first Solar Power Satellite, but then you get another one built every year, and the continuing influx of people and resources builds additional SPSs every year after that.

My expected cost to get that first habitat and first solar power satellite operational is of the order of $20 Billion. But then the investment starts to multiply, and by the time you’ve invested $30 Billion, you’d have 30 Solar Power Satellites in production and your investment ROI is 100% per year (ignoring ground-based costs of receiving and distributing the power, which might be as much as another billion per satellite). Actually, by the time you have two SPSs (ignoring ground costs) or four SPSs (assuming $1B/satellite in ground costs) in operation the operation is self-sustaining and doesn’t require additional capital investments, yet the profits continue to grow.

Assuming the chosen asteroid is Apophis (but see A Choice of Asteroids), the first $10 billion would be spent by 2030, the first SPS operational in 2035 (after spending another $10 Billion), and the entire operation is wildly profitable by 2040 (by which time you’ve invested $30 Billion but your satellites are earning you $30B/year). It sounds like a great investment for my IRA.

A lot of research is needed, and a lot of talent. We need to solve these problems:

Farming in Space (total closed-system recycling)
micro-gravity mining
zero-gravity smelting of ores using recycled reducing agents and probably direct solar power
zero-gravity refining (separation of metals, slags, and effluent gases into valuable component parts)
zero-gravity rapid capture and separation of gases from iron and steel production (we can’t afford to waste that carbon dioxide).
zero-gravity metal forming (turning steel into girders, rods, plates, cables, etc.)
Welding of large structures in space.
Low-cost, human-friendly space suits (ie, skin suits) for hard-working people.
VASIMR (or similar rocket technologies) to use the excess oxygen from the production of iron as a rocket fuel for in-orbit shuttles and to capture asteroids. Oxygen is the primary bi-product of steel production from ore (other than slag, and assuming recycling of carbon), with a ton of oxygen freed for every three tons of iron produced. Thus the 75,000 tons of steel needed for a habitat for the first 8,000 people yields 25,000 tons of oxygen. Building each 180,000 ton SPS (4 km on a side) yields 60,000 tons of excess oxygen. That’s a lot of rocket fuel.
Low-cost launch to LEO. Part of this may be the economy of scale, as very large heavy-lift rockets are much cheaper per ton to orbit than smaller rockets. I believe this entire operation is highly profitable and sustainable if the launch cost to LEO is $1 million per ton or less. While NASA and the Space Shuttle (or its proposed replacements) can’t approach this cost, commercial private-sector efforts can. And the scale of this project is large enough to justify those investments.

There are a myriad other problems to be solved, but most of them are engineering efforts, not R&D projects. They will still require a lot of talented people, and many more people will be needed to work in space – thousands of them, of every persuasion. Miners. Steel workers. Welders. Electricians. Plumbers. Mechanics. Farmers (lots of farmers). Doctors and nurses. Pharmacists. Cooks. Wait staff. Bartenders. Construction workers. Janitors. Barbers and cosmetologists. Massage therapists. Truck drivers & bus drivers (but we’ll call them space ship pilots). Clerks. Accountants. I suspect a lot of movies might be made in space, so add actors and all those people listed in the credits for your favorite movie. And where lots of people go, families happen. So we’ll also need day care workers. Teachers. Playgrounds. Schools. Police. We might even need a manager or two. Counselors. And a divorce lawyer.

If you have a skill, you’re probably needed in space. Welcome to the future.

I Hope I’m Wrong …

2010-02-26T14:02:00.001-05:00

I’ve argued that the future of humanity necessarily involves a future in space. There, we won’t have the room restrictions, resource restrictions, and catastrophe likelihoods that we’ll have so long as we’re confined to the surface of a single planet. There, a single nuclear, or nanotech, or biotech mistake won’t wipe us all out in the blink of an eye.

But to bootstrap into a space-faring civilization takes a huge commitment. Space travel (at least from the surface of the Earth)takes a LOT of energy, which (on average) we don't have to spare. Space travel (and bootstrapping our future) also takes money, which we also (on average) don't have to spare.

One key point of my proposed "space faring future" is that we will need fusion energy, which potentially solves the energy problem. We aren't there, yet, but there is hope. Out as far as the Asteroid Belt, solar energy can handle our needs, but in the very long term (think a thousand years) we’ll need to expand beyond there.

A second key point is that a future in space for humanity is not likely to involve a lot of travel to and from planetary surfaces. Landing deep in a gravity well and launching into space from deep in a gravity well is extremely expensive. I also don't believe that we will colonize Mars or even our moon to any great degree - there's just very little value in that, and a great deal of expense.

That's why I expect that humanity's future will be asteroid and comet based. Comets (and carbonaceous asteroids) provide all of the raw materials (including hydrogen and deuterium for fusion power) that we might need for a space-based civilization, in a readily accessible form. It is relatively cheap and easy to land/take-off from their negligible gravity wells.

However, to get there in the first place (especially with enough infrastructure to build a high-tech industrialized society) will take a lot of energy, which we aren't likely to have to spare until we perfect fusion energy.

I have another very important point, which I haven’t elaborated on the past, largely because it is too depressing.

I don't believe that the USA will be a significant part of humanity's future. We have too many well-meaning people who think our wealth should be spent in other ways, such as feeding the poor, burying excess carbon dioxide, low-income housing, building giant levees around all of our low-lying coastal cities, and (most importantly) preserving the status quo. They want to preserve what we have, or restore what we had, instead of building the future.

I believe that humanity's move into a space-based civilization will be funded by either extremely wealthy dictatorships (think oil sheiks) or other dictatorships that care more about results than about their people or damaging the environment - think China.

You see, we have more than enough wealth to create a comet-based space faring civilization. We could do it now IF we didn't mind launching large nuclear reactors into space (a nuclear submarine is quite similar to a spaceship, a nuclear-powered aircraft carrier could carry more than enough infrastructure and people to colonize an asteroid).

We don't have the needed wealth or energy ON AVERAGE. But there are people (or countries or companies or churches) that have enough wealth that, should they so choose, they could bootstrap the process, and in that way insure their own place in history.

It WILL happen. At least I hope it will - the alternative is likely to be the more-or-less slow demise of humanity, as our per-capita energy falls, as our per-capita wealth averages globally, as billions of people starve and technology fails.

The status-quo is not an option. In an ideal world, we would find a way to raise the global per-capita wealth to something like what we currently enjoy in western civilization (likely making US much wealthier than at present). In an ideal world, we would find a way to do that while reducing humanity's impact on our global ecology (sounds impossible to me). In an ideal world, we would find ways to feed our burgeoning population while leaving most of the world's natural resources untouched (some people argue that we have no right to take the food that sustains the other carnivores of the world, such as sharks, wolves, crocodiles, hyenas, etc.). Other people would argue that it is more important to preserve the endangered spotted sand flea than to build power plants, factories, or housing.

I don't think it is likely to happen in our current society. We have too many people who want to globally average our wealth, too many people more concerned with reducing our impact on the world than on building our future, too many people more focused on taking the wealth of others than on creating their own wealth.

The status quo is likely to lead to a greatly reduced impact of humanity on the global ecology. That will automatically happen when civilization fails and billions starve and we are reduced to a few tens of millions of people living on the edge of starvation in a non-technological world. The remainder of the world (non-human) is likely to recover quite nicely (perhaps minus a few thousand species that have or will die out because of our impact).

At some point in the future, SOME dictator will decide to move HIS society into space, "screw the masses". It WILL happen, and that dictator will thus insure his place in history. The USA is likely to be a small reference in a footnote about a failed civilization, otherwise forgotten.

My personal attitudes (I'm normally a perpetual optimist) and beliefs (I'm intelligent enough to see that there are extremely serious problems in the world) are in conflict. I see that we DO have the resources, but not the will to expend them, and our excess resources are dwindling.

It would cost us a few billion to capture an asteroid, a few billion more to turn it into a factory for Solar Power Satellites (helping the Earth below), a few billion more to create permanent habitats in orbit. The total expenditures ($10B-$20B for this one project) would be less than we spend annually on pet food, or cosmetics. We spend 10 times this on gasoline every year to fuel our bad driving habits and oversized cars. The largest source of wasted wealth may be our excess expenditures on health care: The USA spends DOUBLE the dollars per person on health care than do the 2 dozen counties with better health care (as measured by their longer average life spans). This is a waste of roughly $600 billion, of which perhaps 20% is due to malpractice insurance and procedures instituted only to prevent malpractice claims (not medically necessary). A tiny fraction of this ANNUAL expense would fund humanity’s future in space.

There are so many solutions that we don’t have the will to implement. High-density urban living. Public transportation. Electric cars. Health care without waste. Eating more vegetables and less beef. Recycling (really, we just need less of a wasteful attitude as represented by our use of disposable packaging). Solar power. Geothermal power. Travelling-Wave nuclear reactors (that consume radioactive waste).

Question: What do YOU believe are the long-term goals of civilization? What SHOULD we spend our wealth on?

Lighting our Space Habitats

2009-11-18T15:38:00.001-05:00

In previous posts (Designing a Space Habitat and Farming in Space) I’ve argued that we do not want to use “natural sunlight” to illuminate our habitat and grow our crops. There are three primary reasons:

Simplicity: We must have radiation (and meteor) shielding of about 10 tons per square meter of surface. A complex chevron array of mirrors would be needed to reflect light around this shield, plus mirrors would need active positioning to track the sun. Joints between windows, shield, and structure would be subject to thermal cycling, introducing failure points.
Room: We don’t have enough surface area to position our farms on the inner surface of our habitat where reflected sunlight could be most easily directed. Artificial lighting allows growing crops in rooms with very low ceilings, supporting 5 to 10 times the population in the same size structure.
Thermal Efficiency: Natural sunlight is largely heat, and heat dissipation is the primary limiting factor in the size and population density of a large space habitat. Every watt admitted or generated in the interior must be radiated away. The interior will be warmer than the blackbody radiating temperature of the exterior.

There are other considerations as well. Much of natural sunlight is not photo-synthetically active radiation (PAR). Plants appear green because they reflect this wavelength of light and do not utilize it (chlorophyll has absorption peaks in the red and blue regions of the spectrum). From an energy efficiency standpoint, natural sunlight is relatively poor (worse when considering infrared and ultraviolet which comprise 55% of the sun’s energy flux). Only 1%-2% of solar energy is converted into biomass by plants, compared to 8%-16% of the energy of optimized LED light sources (C4 plants - including crops such as wheat, corn, rice, barley, oats, and sugarcane - have higher efficiency than C3 plants).

Sources for this information offer a wide variety of opinions. For LED lighting, see the research articles at LED Grow Lights Outlet. For sulfur microwave lights, see MacLennan et al. For a discussion of photosynthetic efficiency, see R.J.Bradbury.

Using available information on LED grow lights, optimal plant growth is achieved using approximately 72 PAR watts per square meter. As indicated in my earlier post Farming in Space, we should conservatively allocate 64 square meters per person to maintain a good (largely vegetarian) diet. This equates to 4600 watts per person to grow crops.

We’ll need additional illumination. According to The Engineering Toolbox, direct sunlight provides over 100,000 lux, and full daylight 10,000 lux. An overcast day (1000 lux) is equivalent to the needed light level in a store or a detail-intensive workspace. A normal work (office) environment may only require 500 lux, and home illumination and classrooms only 250 lux. Hallways are even less, perhaps 100 lux. A reasonable average is about 500 lux, which requires 250 watts of white light for my proposed habitat space of 50 square meters per person (ignoring the farms and central park).

The central park area requires much more light – enough to grow plants, and the park will need a white light spectrum. In addition to recreation, the park will grow fruit and nut trees. We have a lot of space to be brightly illuminated, about 10 square meters per person at 10,000-20,000 lux (half of the time), requiring an average of 350-700 watts per person (assuming doped sulfur microwave lamps).

One last point: contrary to current public opinion, I predict that the lights in a permanent space colony will provide moderate (non-zero) levels of ultra-violet light. During exposure to sunlight (containing UV light), human skin produces large amounts of vitamin D, a nutrient vital to health. See the non-profit Vitamin D Council for additional information about the value of this vitamin. “Current research has implicated vitamin D deficiency as a major factor in the pathology of at least 17 varieties of cancer as well as heart disease, stroke, hypertension, autoimmune diseases, diabetes, depression, chronic pain, osteoarthritis, osteoporosis, muscle weakness, muscle wasting, birth defects, periodontal disease, and more.” Vitamin D deficiency may only be the most obvious result of a lack of full-spectrum light in our lives.

Humans evolved to require gravity, and sunlight, and a varied diet. Until we learn otherwise, we need to replicate the conditions of life on Earth very closely in our new homes in space.

Farming in Space

2009-11-06T11:06:00.001-05:00

In previous posts I’ve described plans for space habitats which include allowances and techniques for the closed system recycling we will need to establish self-sustaining life in space.

This post describes in some detail just what is needed, and where I found the information. Fundamentally, we will need to provide recycling for nearly everything in space.

Humans breathe oxygen which is plentiful in the form of oxides and silicates, but rare as the free element in space. We each need a bit less than a kilogram of oxygen per day (0.83kg on average, more under high work loads). Note that processes such as smelting metallic ores use heat and a reducing agents such as carbon to turn metal oxides into the metal plus oxides such as CO2. Green plants turn the CO2 into carbon (or carbohydrates), freeing the oxygen, and the carbon can be fed as raw material into the smelter. The only net products of smelting are metal (such as iron) and oxygen.

Humans consume water for drinking, food growth and preparation, cleaning, even entertainment. Since hydrogen is in short supply (until we can gather and use the resources of a comet, in which case we’ll have more than enough to throw away), we’ll need to carefully recycle water. Each human drinks or eats about 2.6 kg of water daily; more is needed for hygiene and growing crops, a lot more.

Working humans need to eat, on average, about 2500 Calories per day (some estimates suggest 2000, my wife’s diet suggests 1500). This can be provided by about 540 grams (dry weight) of food (50g protein, 70g fats, 420 carbohydrates).

The total consumption of a human is about 4 kilograms of oxygen, water, and food per day, and it should come as no surprise that that the same human produces 4 kilograms of waste (in the form of carbon dioxide, exhaled water, sweat, urine, and feces) per day.

Also unsurprising is that green plants (such as algae) can take those 4 kg of wastes and produce the needed food and oxygen with only the addition of energy in the form of light.

The complications arise from the need for a balanced, nutritious, and tasty diet containing all of the essential amino acids and fatty acids, and from the fact that we do not digest all portions of plants. Cellulose (fiber) is undigestible, and we don’t even attempt to eat most of the plant material of a crop (stems, roots, leaves, bark).

The ecosystem we create in space must be perfectly balanced. When plants produce food for us to eat, they simultaneously produce the exact amount of oxygen needed to metabolize that food. But they also produce those stems, roots, leaves, etc., and excess oxygen to match. All of that extra plant matter must be fed to some other animals (such as rabbits or goats), or to fungi, or to bacteria, or burned. The excess CO2 must be captured and fed back to the growing plants of the next crop, because we don’t exhale enough CO2 to feed the plants, only enough to grow the food we ate – a fraction of the total plant material.

Note that we can meet all of our dietary needs by growing a variety of algae such as blue-green algae including spirulina, and chlorella.

Somewhat surprising is how little water is needed to grow adequate volumes of algae – as little as 6 to 10 liters per person. This is due to the extremely high growth rates of alga under optimal conditions.

However, an algae diet is not only boring, it doesn’t taste good. It is likely to only be used for long space missions where space and payload is at a premium, and even then at least 4 varieties must be cultivated to meet our dietary requirements.

Whether we are growing alga or traditional crops, much of human waste is not readily usable as fertilizer. Portions are, and some bacteria excel at producing nitrates out of urea and ammonia. But much solid waste cannot be so easily processed. Luckily, a technique is available to solve the problem: a Supercritical Water Oxidizer applies high pressure, modest temperatures, and oxygen to burn the carbohydrates to water and CO2, freeing nitrates and mineral salts in the process. This is called the Zimmerman Process.

The process boils down to:

feed CO2 and light to growing plants
harvest human-edible feedstuffs
feed much of the rest to animals such as rabbits, goats, and chickens, as well as vegetarian fish such as tilapia.
burn the rest of the plant matter to produce CO2 and ash (which is fertilizer)
feed food byproducts (and table scraps) to animals such as chickens or pigs (which when harvested produce still more byproducts)
use that Supercritical Water Oxidizer on animal and human wastes to convert them back into CO2 and fertilizers for the plants.
Condense water out of the air for drinking, and recycle irrigation water (which holds excess fertilizers) for plants.

Remember, as we are growing crops we need to feed them extra CO2 (much more than humans exhale), and store the excess oxygen they produce; we’ll restore the balance when we burn the crop residues and wastes. The “burning” doesn’t have to be an open fire. Feeding crop residues to goats counts as burning, as does using the plant matter as a reducing agent in the production of iron – both produce CO2 and free the water in the carbohydrates.

What crops should we grow? In general, dwarf varieties of grains, beans, and vegetables will satisfy most of our needs. We’ll have bread and pasta from wheat, rice, soybeans, oatmeal, lettuce, tomatoes, melons, potatoes, sweet potatoes, onions, herbs, etc.. I’m sure we’ll grow strawberries and other fruits, and eventually our parks will also serve as a source for nuts and fruits such as apples. I’m also quite certain we’ll grow grapes for wine, barley and hops for beer, coffee, and tea. Some human appetites insist on being satisfied.

That does leave the question of space. Just how big must our farm be? According to T.A. Heppenheimer’s excellent book Colonies in Space, the answer is derived from existing studies and experiments in high-intensity farming. Using dwarf varieties that have also been selected for short planting-to-harvest times, using interplanting (sowing the next crop before the current one is harvested), and optimizing CO2, water, light, and humidity, Heppenheimer calculates that 60 acres of farmland will support ten thousand people. This is only about 25 square meters per person.

I propose to average less than half that efficiency and allocate 64 square meters per person to include space for crop tending, to support a greater variety of foods, and to allow some extras to feed goats (for milk, cheese, and meat), rabbits (for meat), and chickens (for eggs and meat). Note that crops don’t require high ceilings; a single meter is good enough (on average), yielding a volume requirement of 64 cubic meters per person. This is less than the 100 cubic meters per person of living space I recommend in Designing a Space Habitat, where I also recommend about 33 cubic meters of workspace volume and an equivalent amount of overhead.

In that previous post, I assumed that 3 levels of living space would be allocated for the farms, but that may not be the best option. Rather, the farms are the primary source of waste heat. All that light energy ends up as heat and must be dissipated. The end caps of our cylinder expose a great deal of surface, so it makes the most sense to place our primary heat sources – the farms - adjacent to them. Using 8 meters along both end caps as our farms provides 64 cubic meters per person, independent of the size of our habitat (as long as we use the Kalpana geometry). Many plants need little gravity, indeed aquaculture (raising algae and fish) may require none, and these may be placed near the center. I expect that we’ll place livestock near the outer rim, as their needs for gravity are likely to mirror our own.

A future post will describe the lighting needs of the crops, and the technologies we’ll use to provide it.

Designing a Space Habitat

2009-10-29T18:41:00.001-04:00

A range of designs have been proposed for space habitats. Some appear to be mostly artistic concepts, others are much more serious. They include:

(From Wikipedia http://en.wikipedia.org/wiki/Space_habitat)

Bernal sphere - "Island One", a spherical habitat for about 20,000 people.
Stanford torus - A larger alternative to "Island One."
O'Neill cylinder - "Island Three", the largest design.
Lewis One^[4] A cylinder of radius 250m with a non rotating radiation shielding. The shielding protects the micro-gravity industrial space, too. The rotating part is 450 long and has several inner cylinders. Some of them are used for agriculture.
Kalpana One, revised^[5]A short cylinder with 250 m radius and 325 m length. The radiation shielding is 10 t/m² and rotates. It has several inner cylinders for agriculture and recreation.

There are other well-known structures from science fiction literature, including

Rama (a 20x50km rotating cylinder) from Arthur C. Clarke’s novel, Rendezvous With Rama
Space Station V (from the movie 2001: A Space Odyssey)
Babylon 5

Of these, the most complete design is “Kalpana One, Revised,” which properly accounts for issues such as shielding and rotational stability. Most designs presume that it is best to provide windows to admit natural sunlight, but there are many reasons to prefer artificial light sources, primarily involving heat, but also the need for shielding. For adequate shielding from radiation and meteors, the outer walls of the habitat must mass about ten tons per square meter. While transparent quartz windows could be built of this thickness, most designs involving natural sunlight use mirrors to deflect sunlight around shields of stone. But the admitted heat is the real problem (discussed below).

In my previous posts, including Our First Colonies In Space, Life in an Asteroid, and Our Homes, the Comets, I assumed that we would tunnel into asteroids and comets, enclose and spin them for gravity if they were small enough, or build spinning structures inside them if they were too large.

But while writing a sequel to my short story Apophis 2029, I realized that the best choice was simply to build one or more space habitats from the raw materials of the asteroids and comets. I came to this conclusion because of considerations for effective use of space, the stresses of spinning large objects for gravity, and (most importantly) thermal dissipation.

People consume energy in their homes, workplaces, and travel. Much more important, food requires a large amount of energy in the form of light for growing crops. After extensive research on plant needs, high-intensity farming, and lighting technologies, I concluded that the minimum light levels needed requires 4 kilowatts of very-high-efficiency LED lights to grow the food for one person (assuming a primarily vegetarian diet – you need more to grow additional crops for livestock). Add to that the per-capita electric consumption in the U.S.A. of about 1.5 kilowatts, add a little more for contingencies, and I realized we need to plan on 6 kilowatts of energy consumption for every human aboard the habitat.

That’s not too bad, especially considering that readily available solar power can easily provide such levels and at a modest cost.

But energy consumption turns into heat, and heat must be radiated away. The bottom line is that we must allot 19 square meters per person of surface area assuming black body radiation at a temperature of 0 degrees C. It does not help to plant little radiators all over the surface, as they interfere with each other. All that matters is the apparent size of the habitat from a distance, and how closely it approaches the ideals of a black body radiator. Of course, we could use active cooling to heat radiators to much higher temperatures while cooling the interior, but I prefer passive techniques so that a failure of the cooling system doesn’t rapidly result in cooking the inhabitants.

There goes my idea that a million people could thrive in a cubic kilometer of comet. There is plenty of room, more than enough materials. Unfortunately, their waste heat would rapidly boil their home away.

Also, solar light has a large content of heat – and that excess, too, must be radiated away. Sunlight is not energy efficient for growing crops in a thermos bottle (which is what a habitat in space effectively is).

So, my revised plan calls for 20 square meters of surface per person. Also, to provide radiation and meteor shielding equivalent to the Earth’s surface requires 10 tons of shielding per square meter of surface – and thus 200 tons of shield mass per person (regolith is fine, slag works well and is dense, ice is best as long as it doesn’t boil away). But the needed surface area and shield mass per person are constants.

My earlier thoughts on structure did not consider rotational stability, and the folks that designed Kalpana One came up with some very strong arguments that a spinning cylinder is best, and that the width of the cylinder should be 1.3 times the radius. Thus, a cylinder of radius 100 meters (spinning at 3 rpm for 1 G gravity along the outer rim) should be 130 meters wide. That gives a 1-G living area of a little over 80,000 square meters, a total surface area of over 144,000 square meters, and thus a maximum population of 7,200. This structure provides 11.25 square meters (121 square feet) per person of 1-G living space. Is that enough?

It’s comparable to the space provided (per person) in many hotel rooms and cruise ships. But few couples want to live in a 242 square foot efficiency for long, although 28 sm (300 sf) studio apartments are common in many expensive cities.

There is no need to live only on the outer 1-G surface. Assuming 3-meter intervals, the next level up provides 97% of a G. Surely that is adequate. And now we have 22.5 square meters per person of available living space, equivalent to 450 square feet per couple – or 900 square feet for a family of 4. A third living level raises the per-person space to over 33 square meters – 675 sf per couple – 1350 sf for a family of four. Not spacious, but certainly comfortable.

Humans need space for living, working, and of course for growing food. We must allot some space for office space, work space, schools. A single level should suffice (11 square meters per person), partly because some people will work in the farms, or in their homes, or outside the habitat entirely (such as in the mines, the smelters, the steel mills, the solar power satellites, etc.).

Each person requires approximately 64 cubic meters for crops, but crops don’t require 3-meter ceilings. Allocating 2 levels for agriculture may be tight, but 3 levels is more than enough and provides some excess capacity for the production of meat, milk, and eggs.

We need a little more space for overhead: storage, aisles, conduits for air, water, sewage. So we add an 8th level for good measure. That still leaves an interior cylinder with a radius of 75 meters as a park or recreation area. It has 3/4ths of a G of gravity. The opposite side is more than 500 feet overhead – it will feel spacious enough, and 15+ acres of playgrounds, hiking paths, trees, and grass will provide a little bit of Earth in space.

But there’s no need to leave the end caps – the walls of our cylinder – as bare metal. We should build offices, low-gravity facilities (perhaps hospitals), hotels, etc. along those walls. Allocating 15 meters of depth along each end-cap for such purposes still leaves a hundred-meter-wide park, now with only 12 acres of usable space, 100 meters wide by 470 meters around. The lowest level of the end caps is a perfect place for shops and restaurants.

The above ramble describes the capacity of a 100-meter radius cylinder, spinning at 3 rpm to provide Earth-normal gravity. This spin rate is often considered the maximum for a rotating space habitat, as most people (but not all) can adjust to it. More people can adjust to 2 rpm, and essentially everyone has no problem with 1 rpm. So how much room do we get with these and larger structures? Can they be built?

This table shows the size, possible population, and mass (in kilotons or kT) of the external steel shell, the internal steel infrastructure, and the shield (total mass of steel shell plus rock). Note that once the steel shell reaches a mass of 10 tons per square meter, additional shielding is not needed. For a reference point, the total mass of steel in a modern aircraft carrier is about 60,000 tons, about 20% less than the smallest habitat. The dimensions given are of the habitable volume; the outer walls are assumed to be an extra 5 meters in thickness to provide the volume needed to contain the shield mass (but that extra external area raises the maximum population as well). The thickness of the outer steel shell is also given, in meters, and it ranges from 3cm (1.2 inches) in the 100 meter cylinder to 1.31 meters (4 feet) in the largest. The table also shows the percentage of the asteroid Apophis needed to build this structure, or alternatively the minimum size of a rocky asteroid large enough to build it. *Note that the largest structure would require a nickel-iron asteroid, as there is no rocky shield mass needed.

RPM	3.0	2.5	2.0	1.5	1.0	0.8	0.4
Radius	100	143	224	398	895	1,590	4,621
Width	130	186	291	517	1,163	2,067	6,007
Population	8,087	16,010	38,005	117,491	585,398	1,839,804	15,457,797
Central Park	100	156	261	487	1,133	2,037	5,977
Ceiling	150	236	397	745	1,739	3,131	9,191
Acres	12	29	80	281	1,529	4,949	42,625
Steel Shell (kT)	38	105	385	2,092	23,258	129,560	3,154,722
(thickness)	0.03	0.04	0.06	0.11	0.25	0.45	1.31
Steel Structure (kT)	36	71	168	519	2,584	8,117	68,166
Shield (kT)	1,580	3,096	7,216	21,406	93,822	238,401	0
Total Mass (kT)	1,653	3,273	7,769	24,018	119,664	376,078	3,222,888
% Apophis (27 mT)	6.12%	12.12%	28.78%	88.95%	443.20%	1392.88%	11936.62%
min.asteroid	107	134	179	260	445	651	924*

It is clear that Apophis contains enough raw materials to build habitats supporting 125,000 colonists in up to 16 structures. It is interesting that a 1-kilometer nickel-iron asteroid (of which there are approximately 50,000 in the main belt) provides enough iron that (adding the resources of a small carbonaceous chondrite for carbon, oxygen, and water) a 9x6 kilometer cylinder could be built, supporting over 15 million people. Still larger structures may be constructed; steel has adequate tensile strength for structures large enough to support a billion people, but they become wildly inefficient, requiring nearly 10 times the steel per person.

I plan additional posts providing details on farming in space, on solar power satellites, and on the economics of life in space. It is clear that space habitats are feasible, and that commerce based upon tourism and the construction and maintenance of solar power satellites can pay for it. The obstacles are the difficulty of the bootstrap process:

capturing an asteroid such as Apophis into Earth orbit
Launching the tools to mine the riches of the asteroid, the tools to smelt its ores into steel and other valuable materials, the tools to shape that steel into the plates, beams, and girders needed to build things
Launching the people to make it possible with enough consumables to get past the bootstrap.
Designing and implementing closed-system recycling facilities capable of efficiently converting human wastes (and crop residues) into food, oxygen, and water.

Once enough infrastructure is in place, the colony should not need the addition of oxygen, water, food, or structural materials. High tech tools will be needed, including whatever is needed to construct solar cells, but the raw materials would already be in place. The Earth will export technology, tools, vitamins, pharmaceuticals, and people. In exchange, the Earth will receive bountiful energy from the Sun, with zero carbon footprint.

But that, too, will take time, energy, and especially people. In the long run, the demand for people in orbit is likely to exceed our capabilities of putting them there. And that, too, is the subject of a future post.

A Choice of Asteroids

2009-10-23T20:02:00.001-04:00

I began researching this post believing that Apophis (with its April 13, 2029 close approach) was our best opportunity to capture the resources of an asteroid for humanity and the space program.

Soon I realized that the selections are bountiful (or frightening, depending upon your point of view).

NASA maintains several valuable web sites and services, including

the Potentially Hazardous Object list (over a thousand) at http://neo.jpl.nasa.gov/orbits/ (where you can display an orbit animation)
the Small Body Database Browser at http://ssd.jpl.nasa.gov/sbdb.cgi which lists 3,000+ comets and 400,000+ asteroids
the Near Earth Object Program at http://neo.jpl.nasa.gov/
The Sentry Risk Table at http://neo.jpl.nasa.gov/risk/ listing PHOs in order of threat. Apophis is currently #4, not based upon 2029 or 2036 but the 2068 approach.

As I described in my post Capturing Apophis, these objects are far too large for us to simply man-handle. We must use finesse, or more precisely, we must use the gravitational influence of a body such as the Earth to do most of the work for us. We can nudge small to medium size bodies a bit given months or years of head start. So, we need objects that pass close by, perhaps within the orbit of the Moon.

Plus, I’m interested in objects we can capture in my lifetime.

Here is a list of potential asteroids. Their distance of closest approach is given in Earth radii (1 Er = 6400 km). For reference, the Moon averages 60 Er (Earth radii) away. This list is in order of close approach date.

2005 YU55 passes at 25 Er on 8-Nov-2011. It’s 120 meters across, masses 3 million tons. I wish it passed later – it would make a wonderful practice asteroid but we’re not likely to be able to launch a deflection mission in time.
2008 UV99 passes at 7.16 Er on 30-Mar-2019, is 400 meters wide and masses 87 million tons.
2001 FB90 passes at 13 Er on 24-Mar-2021, is 349 meters wide and masses 58 million tons.
2007 RY19 passes within 0.89 Er on 12-Mar-2024, is 110 meters wide, masses 1.8 million tons.
2001 CA21 passes at 6.41 Er on 9-Oct-2025, is 677 meters wide and masses 422 million tons.
2001 WN5 passes at 37.5 Er on 26-Jun-2028, is 780 meters wide, massing 646 million tons.
Apophis 99942 passes at 5.86 Er on 13-Apr-2029, is 270 meters across and masses at least 25 million tons.
2007 FT3 passes at 22 Er on 03-Oct-2030, is 340 meters wide, masses 54 million tons.
2009 UN3 passes at 19 Er away on 09-Feb-2032, is 919 meters wide massing just over a billion tons.

Note that the sizes are estimates based upon the apparent brightness of the asteroid. None of these have been imaged and measured. The masses are estimates based upon a spherical body of that size with a density of 2.6 tons per cubic meter (partly porous). A solid body would mass more, nickel-iron much more.

This list is not exhaustive, and some of these asteroids may be moving too fast (or not have suitable advance rendezvous orbits) for our purposes. But all 9 of these pass close enough to the Earth that their subsequent orbits are changed by the Earth’s gravity, and a relatively small nudge can be used to control a gravitational slingshot and choose its subsequent path. Some may require multiple slingshots and many elapsed years before they can be parked in a suitable orbit, but even the smallest of these (2007 RY19 at 1.8 million tons) contains enough resources to pay for the effort many times over.

There are many other asteroids from which to choose. A number of asteroids are in horseshoe or spiral orbits near the Earth, and may make suitable low delta-V rendezvous targets. Many more are easier to reach (in terms of required delta-V) than the surface of the Moon. Some of these are nickel-iron asteroids, others may be extinct comets containing huge amounts of ice. One estimate is that 6% of asteroids may be extinct comets.

We need better observations of all of the above objects. If one were a carbonaceous chondrite or an extinct comet, its value would be immensely greater due to the high content of carbon and water – the stuff of life. If one was nickel-iron then that, too, would have extra value. But all asteroids have great value once they’ve been captured into a stable Earth orbit, as all of them contain oxygen, silicon, magnesium, and iron.

Clearly, we don’t need to fight over these trillion-dollar resources. There are enough potentially valuable asteroids to share.

Recipe for a Space Habitat

2009-10-15T18:23:00.001-04:00

To build permanent habitats for people to live in space will require several needs to be addressed:

Living space providing adequate room plus radiation and meteor protection
Gravity or its equivalent
Oxygen to breathe
Water to drink
Food to eat
Something profitable to justify life in space

Luckily, some of these are easily addressed, as certain asteroids have all the resources we need, including the majority of the asteroids in the belt – the carbonaceous chondrites.

STEP 1: Capture an asteroid into a useful orbit. The next great opportunity is the asteroid Apophis 99942, which will be in a location suitable for capture in 2029. See my post, Capturing Apophis for details. The good news is that Apophis contains 50 million tons of resources, including 10 million tons of iron, 15 million tons of oxygen, 12 million tons of magnesium, and perhaps 8 million tons of silicon. The bad news is that we presently believe that Apophis is an LL Chondrite, low in volatiles including water, carbon, and nitrogen, also relatively low in calcium, aluminum, and titanium. Available carbon is likely less than 0.2%, water less than 1%. Still, half of these values equates to 50,000 tons of carbon and a quarter-million tons of water.

How much water and carbon is needed? Studies of high-intensity farming techniques suggest that about a half-ton each of carbon and hydrogen are needed per person to grow crops for food and oxygen recycling. This is equivalent to about 3 tons of carbon dioxide and 5 tons of water, per person, much of which will be contained in the growing plants of our farms. Plants are, after all, carbohydrates. We also need significant amounts of nitrogen (for proteins), and phosphorus as well as various trace elements. But all of these are abundant in ordinary asteroids except carbon, hydrogen, and nitrogen. The most common asteroids, carbonaceous chondrites, contain these volatiles in abundance.

Still, it is clear that even a dry rock like Apophis contains enough raw materials to support as many as 50,000 people.

STEP 2: Establish a temporary beachhead. An empty shuttle tank works great.

An empty Space Shuttle SLWT External Fuel Tank has a hydrogen tank 8.4m by 29.5m (97x27’), and an oxygen tank 16.6m by 8.4m (54x27’); these function nicely as pressurized crew quarters. If the hydrogen tank is converted to recycling (growing plants and recycling wastes), its 1493 cubic meter volume could support about 36 people who reside in the oxygen tank volume (553 m^3), or about 15 cubic meters per person (2x2.5x3m).

You bury the tank for radiation and meteor protection. Five meters of regolith gives about the same protection as Earth sea level; we could get by with three meters on top.

STEP 3: Mine the asteroid and use a solar furnace (or other techniques) to smelt it into useful metals and free oxygen. Also, the first gases emitted when you heat up the regolith are CO2 and H2O. Save them. And note that all the leftover slag is extremely valuable as radiation shielding for the habitat we want to build, so don’t throw it away, either.

To yield enough water and carbon dioxide to grow food for one person, you’d need to process only 50 tons of ore from a carbonaceous chondrite like the Murcheson meteor, but more like 500 tons if Apophis is truly an LL chondrite. You’ll get a little excess carbon which lets you make steel instead of just iron. 100 tons of steel. As a bi-product, you’ll end up with perhaps 25 tons of oxygen, which you’ll want to save, also. This is a good use for a few more empty shuttle external fuel tanks. We’ll be using oxygen as fuel, I suspect, in VASIMR type thrusters powered by solar energy.

STEP 4: Establish a farm in that empty hydrogen tank (or in several of them as the colony grows). My estimates of needed space are based upon 64 square meters per person of crop area, using high-intensity techniques, and using LED light sources. I also assume hydroponic techniques instead of soil, because it’s easier to recycle the root mass. We won’t use soil (even if it’s free and abundant) until we have a huge surplus of carbon and water to waste.

Note that we need to feed extra CO2 to the growing crops – humans don’t produce enough to grow everything we need, because of the small fraction of plant material that is edible. We’ll even be burning the dried crop residue to create CO2, or turning it into coke (carbon) to improve the efficiency of iron production.

STEP 5: Start building Solar Power Satellites. You’ve got the steel, and all the magnesium you could want, plus more than enough silicon. A square kilometer array of solar panels or collectors intercepts a gigawatt, yielding a net 200 megawatts to Earth. But why stop at a gigawatt? You’re building in outer space where it is simple to build large structures.

A circular array with a 1.6km radius would yield 4 gigawatts of power to be beamed to Earth from geosync orbit. Each generates $1B per year in wholesale electricity (at $.03/kwh). With no energy costs – just maintenance.

The steel & other raw materials for each one consumes about 1% of Apophis’ regolith. By the time you’ve built 50 of them, your revenue is $50 billion a year, and you’ve only consumed half of Apophis.

STEP 6: While you are building Solar Power Satellites in one factory, you can be building a large, permanent, self-sustaining habitat in another. Many designs have been proposed, and I, personally, like a rhombic triacontahedron. It is constructed from 30 identical rhombic steel plates. A simpler design (but more difficult to build) is a cylinder. Both would be spun for gravity.

For radiation and meteor shielding, you need about the same mass of shield as the Earth provides us: 10 tons per square meter. That’s about 5 meters of regolith, or 3 meters of slag (which is nice and dense). I realized that this much mass, spinning at one G along the periphery of a sphere (which is close to a rhombic triacontahedron) exerts an outward force entirely equivalent to a pressure vessel, whose characteristics are well known. To contain a force of 15 tons per square meter (3 tons of which is air pressure), a spherical pressure vessel 100 meters in radius only needs to be about an inch thick, masses about 25,000 tons of steel.

The limiting factor for population is likely to be heat dissipation. Using very high efficiency LED light sources to grow our food, and minimizing all wasted energy interior to the structure, we need about 20 square meters of cooling area per person (assuming passive cooling – the only safe kind). Thus, a 100 meter radius habitat, spinning at 3rpm for 1 G, has sufficient area for a population of about 6,000 people. It takes about 4 tons of steel per person to build the pressure vessel. Since the area per person is constant (20 square meters), and the amount of shielding per unit area is constant (10 tons per square meter), each person needs 200 tons of shielding. Thus the habitat for 6,000 people requires a 25,000 ton steel pressure vessel, plus probably that much again for internal structures, plus 1,200,000 tons of shield mass. This is 2.5% of Apophis – we could build 20 of these with the half left over from building 50 solar power satellites.

Spinning at 3rpm is too fast, you say? If the radius of our vessel is increased to 225 meters (yielding 1 gravity with a 2 rpm spin), our pressure vessel needs to be 5.6 cm (2.25 inches) thick, and requires nearly 300,000 tons of steel. But it now is large enough to support a population of over 30,000 people. And its construction consumes 12.5% of Apophis. Yes, we can still build 4 of these: one in Apophis orbit, one above geosync as the ideal place to maintain those solar power satellites, and I’m sure we can find places to stash the other two. How about L4 and L5?

Sorry, but if you want to spin at 1 rpm (radius of 890 meters), it takes all of 2 Apophis-size asteroids to provide the needed raw materials and would have living space to support about 500,000 people. But it takes more steel per person the larger you build it – there is no economy of scale, as larger and larger pressure vessels take more and more steel per unit area (and thus per person). But as long as we are doing the math, if you raise the radius to 4 kilometers, your steel shell must be a full meter thick, and itself provides all the shield you need.

Evolution

2008-10-31T08:11:00.001-04:00

Evolution - or survival of the fittest (or luckiest) - is a readily provable fact, and one not limited to species: Evolution also applies to ideas (memes) with areas as diverse as religion, music, fairy tales, and urban legends.

The concept of evolution is simple: That which successfully reproduces, survives. If pressures (due to competition or predation) limit the growth of something which has a natural variation (a choice of religions, or music genres, or tales, or an ecosystem, or apes), those variants which most successfully reproduce will succeed versus those less suitable, or less lucky.

Note how few successful religions abound which forbid sex. There have been short term experiments in this direction. More subtly, religions that don't have a strong philosophy of proselytism tend to be dominated by those that do. Remember, survival of the fittest is really just survival of those that successfully reproduce. See The Purpose of Life.

Evolution of species continues today. Mankind is forcing change, which drives evolution. Some of this is merely speeding long term trends (such as reduced success of amphibians in general, or the loss of many marginal species like the spotted owl). Other changes are more worrisome (such as the evolution of anti-biotic resistant bacteria).

Especially with animals (including humans), there are two forces that dominate evolutionary pressures. In addition to reproductive success due to superior survival characteristics, there is reproductive success due to sexual selection (ie, how members of each sex choose mates). More colorful animals are easier to find, and the most showy male is likely to get the most females and successfully reproduce even though he is also the most visible to predators and ends up living a shorter life. Sexual selection may also explain extremely large sauropod dinosaurs; perhaps the males/females liked (or could see) tall females/males better - and sought them as mates - leading to runaway selection for this feature.

Even mankind continues to evolve in several ways, and indeed demonstrates evidence of very recent evolution.

For example, there is strong evidence that people have been evolving for external sexual characteristics. Human females have proportionally larger breasts, narrower waists, and broader hips than other primates. (As a human male, I do love that shape.) Human males have shapes that illustrate upper body strength, and have a penis that is larger in proportion to body size than any other ape. Apparently males have been selecting for large breasts and hips (especially in contrast to waist size). And women have been selecting men with broad shoulders, large muscles, and a big penis. And bad boys, at that.

Watching many reality shows (and especially MTV) suggests that human females are still actively selecting for strength, size, and sexual prowess; intelligence is clearly not a requirement. Likewise for human males, actively selecting voluptuous, athletic females with exotic eyes, long hair, and aggressive sexual attitudes.

Our technology is also having a significant effect on the human specie: we are becoming less diverse, as our ability to travel globally is reducing regional and racial disparities at measurable rates. In a few thousand years, there may be no remaining significant racial differences at all as we continue to interbreed and blend. Personally, I think this is a good thing.

We are also enabling the survival and allowing the reproduction of humans who would never live to adulthood without technology and/or large social organizations to care for them. I think this is a bad thing (when genetically caused), as I prefer that our children be smarter, stronger, and healthier. I know many people find my attitude offensive, but really, people, it is not in humanity's best long term interest to support or encourage the reproduction of serious genetic defects or low intelligence. Again, see my post The Purpose of Life.

A few other rambles:

Humanity is the ocean's most effective predator, and our fishing techniques are rapidly changing (evolving) fish to have less desirable characteristics. Fish are maturing younger and at smaller sizes as we select only the largest (previously most successful) fish. Fish that humans like to eat are being selected out - made extinct - versus undesirable, bony, badly tasting, or hard-to-capture fish. A tight school of fish may have worked to confuse dolphins or sharks, but it is an bright sonar target easily capture by our mile-wide nets today. And small and mid-size fish that avoid schooling behaviors make poor (unprofitable) targets.

Note that the world's most successful plants and animals are those whose evolution has made them desirable food for humans (cows, chickens, pigs, wheat, corn, rice, etc.). Then we help them thrive and reproduce, in numbers far exceeding natural populations.

Some people have argued against the use of windmills as a source of renewable electric power, based upon the fact that the turning windmills kill many birds. Tear down the windmills, drill for oil, save the birds. The reality is that more birds are killed by cars and trucks on the highway. (The activists would probably like to outlaw cars and trucks, too.)

I believe in the value of evolution: the birds that learn to avoid the rotating windmill blades will survive and reproduce. We can already see this effect along our highways: fifty years ago it was much more common to hit a bird on the highway, even though speeds were significantly lower then. Think of it as evolution in action (thank you, Larry Niven).

Last, the implications of evolution to a field near and dear to my heart: science fiction.

Contrary to nearly every movie alien, any intelligent life we meet in outer space will not be highly effective carnivorous killing machines. Au contraire, they will be (on their home planet) relatively weak and defenseless, needing superior intelligence to survive and reproduce. A dominant carnivore, or a herbivore that does not need to fear predation due to successful defenses (armor, size, quills, poisons) will cease to evolve. Every intelligent alien ever depicted with huge fangs, great strength, speed, armored skin, etc., is absurd, as they would never have evolved intelligence.

No, the most intelligent species will be those that are slow, weak, need protection from the elements, need to build and use tools to thrive, and need a civilization to defend against the superior strength, speed, and teeth of their planet's versions of lions, and tigers, and bears.

Of course, there is some evidence that intelligence is not a long term survival characteristic. We haven't yet met a single intelligent alien.

The Earth's Fragile Ecology

2008-10-26T08:06:00.001-04:00

Most of my readers know that I'm fundamentally an optimist (see I am an optimist), and that I believe that science and technology (along with human ingenuity) can and will solve most (hopefully all) of our problems caused by technology and the resulting global population growth.

But it won't be easy, or cheap.

Most people seem unaware of the major ecological problems we face, focusing instead on a few relatively minor (but well publicized) potential problems such as Global Warming or loss of biodiversity.

Here are a few more for your consideration.

Loss of topsoil: Globally, current farming techniques results in topsoil being lost to erosion at rates far greater than natural replenishment. Topsoil (the only part of the Earth's regolith that can readily support crops) is being lost at a huge rate, resulting in reduced crop yields and even desertification in some areas. Currently, the recommended solution is to globally convert to no-till farming, which has the problem of requiring greatly increased use of herbicides and insecticides with their attendant and largely unknown long term effects.

Ocean anoxia: The huge influx of topsoil and fertilizer into the oceans is producing larger and more frequent dead zones, where nearly everything larger than a bacteria dies due to lack of oxygen. All of the nutrients lead to bacterial blooms which consume all free oxygen, and while some mobile fish can swim to the surface to gulp oxygenated water or swim out of the region, bottom dwellers and the myriad small critters that comprise the bulk of the food chain have no such ability. They die, and so do other life forms that depend upon them. This process happens to thousands of square miles every year, and the area and event duration is increasing.

Overfishing: The oceans are being depleted of desirable foodstocks are rates far greater than can be maintained. Already, many once common seafoods are becoming rare, and many fisheries are now effectively ocean deserts, completely devoid of large fish. At present, there are two approaches to solve the problem. One is to create huge "no fishing" zones to serve as replenishment stocks for the regions around them. This works in the short run (assuming enforcement by fast, armed ships), but eventually the fish will evolve to avoid fishing zones. The second solution is one that our leaders have done completely backwards. They have established minimum take sizes, where the fisherman is allowed to keep only fish above a certain size. Sounds good at first, as the young fish are allowed to live, feed, and grow. Unfortunately, there is something called evolution. Fish which once grew quickly to a large size (to avoid predation) are now evolving to grow more slowly and to reproduce at a much smaller size (avoiding predation by the most effective ocean predator, us). As a consequence, reproductive success is reduced, and the remaining fish are becoming less and less desirable. The solution? Capture (and eat) medium sized fish, encouraging these species to grow quickly to a large (safe) size and to produce large numbers of offspring to ensure that enough of them escape us to maintain their species. But this will take technology, and leadership.

Falling water tables: Everyone has heard of (or experienced) the relative and growing shortage of fresh water. Many people don't realize how serious the problem has become. Many cities (especially in desert areas but including many water-rich areas such as Orlando, Florida, USA) are pumping fresh water out of the ground at rates much greater than natural replenishment. Eventually the wells will run dry. Going deeper is often not a solution because of salt water, no water, or pollutants such as oil, lead, or arsenic. Along the oceans, pumping fresh water out of the ground encourages salt water incursion, a serious problem. One side effect of excessive ground water pumping is that springs dry up, and rivers that once ran to the ocean now shrivel and disappear. Water wars will result when cities / states / nations consume the fresh water that other downstream cities / states / nations need to survive.

Chemical pollution: To me, the most serious pollution issue is from the long term unanticipated side effects of biochemicals we create and dump into the environment. These include insecticides, herbicides, drugs, hormones, and especially antibiotics. We don't understand the long term effects of insecticides and herbicides; we ignore the possible unintended effects of long exposure to low doses of hormones and many other drugs (traces of which can be detected in many or most municipal water supplies), and we are rapidly breeding (thanks to evolution and the overuse of antibiotics) new bacteria (and likely viruses) which are immune to all known antibiotics. This alone could result in a plague which could destroy most human life.

The growth of cities: We tend to put cities (especially large, growing ones) at the worst possible places: in river valleys, along flatland floodplains, along the mouths of rivers. The same places that are the best possible farmland. We should build them on mountains, in deserts, rocky, hilly terrain, even floating on the oceans. Leave the good farmland to farming. Leave the river deltas for farming and allow the annual floods that replenish their topsoils and ecologies. Our cities continue to grow at alarming rates, covering the surrounding land with buildings and asphalt. And polluting or burying the former topsoil in the process.

Are there long term solutions? My favorite is to move humanity off of Planet Earth and into space habitats. See Colonizing the Solar System and Population Unlimited. Unfortunately, I expect that humanity will tend to continue to exploit the Earth in ever greater degree until the point is reached where most of the population will abruptly die. And then the survivors just might be smarter and do it right the next time. That, my friend, is evolution in action.

ECONOMICS 101

2008-10-24T13:01:00.001-04:00

Some fundamental tenants, followed by discussion and ramifications:

There is no such thing as savings.
Money is not real (although it is a valuable accounting tool).
Prices are set by supply and demand.
Any attempt by people or governments to change any of the above is doomed to failure.

There is no such thing as savings, other than to store food or other supplies in a larder. We all live off of the current productivity of workers. For you to retire, you must convince someone else to work on your behalf (to provide you with food, clean water, sanitation, energy, health services, everything you need). At the beginning of life, your parents did that. At one time, we would depend upon our children to provide for our old age. Investing in children was investing for retirement. But that time has past.

In today's society, we save for our retirement and therefore depend upon society to care for us. The only way that works is if:

We invest a portion of our current work productivity in infrastructure (capital) so that other, future, workers can be more productive. (In exchange, we expect those future workers to support us in the future via a fraction of their increased productivity.)
A large enough fraction of the population is working in primary production to provide for the non-workers.
The population dynamic is such that the future expected number of retirees is proportional to the future number of primary workers. This does not match reality!

Money is not real. Actually, money can be real, if it consists of coins or other valuable items (gold coins are real, as are gems and many other commonly recognized commodities). Paper money, or a coin whose value is based on a promise, is not real. Unfortunately, governments can print more money or stamp more coins. This dilutes the value of the existing currency, making it proportionally less valuable. Note that the total value of the good and services in the economy remains unchanged - only the number (accounting value) associated with the measurement of the economy increases.

The picture is not really so simple, but it will serve our purposes. The great thing about the concept of money is that it creates an accounting tool that allows us to share productivity, to allow a civilization to work together (some farmers, some miners, some builders, some engineers, etc.) where each of us can achieve greater productivity in a narrow field than any of us could if we each had to provide for all of our needs. Can a farmer build a house or a car? Can an engineer raise cattle and chickens for meat, milk, eggs? Yes, but not as well as a professional. And that, my friends, is the true source of wealth.

Prices are set by supply and demand. This is always true in the long run, although short term variation due to greed, fear, stupidity, and the delays needed to change production will happen. Capitalism works, for the most part, but it is slow to respond to changing markets. If oil prices jump, economic theory says that exploration, production, and distribution will increase supply to match (or exceed) demand. However, it takes years to find new sources of oil, drill the wells, build the distribution networks, the refineries, etc..

The government should have a role in pricing, to ensure fair competition, avoid fraud, and to make certain that the consumer fairly pays all costs associated with a commodity. For example, if a bottle of water is sold to the consumer, the price (manufacturing, distribution, and taxes) should reflect the total life cycle cost of that bottle of water, including the renewability of the water source (no dropping water tables stealing water from the future), and the disposition of the bottle (the cost of disposal or recycling - don't dump our current waste on our children).

Any attempt by people or governments to change any of the above is doomed to failure. History is full of failed attempts to control an economy. Price fixing invariably leads to shortages. Government attempts to define production invariably result in reduced choice and quality, with higher prices. Printing more money causes inflation. And since there is no such thing as savings, it is incredibly stupid to "invest" social security funds in government debt. All such debts must be repaid by taxes on future workers, whether you call them social security taxes or anything else. Who could come up with this concept? Unless the worker's funds are invested in things resulting in future productivity gains (which can include factories, research, infrastructure), this scheme is doomed to failure. Yes, I'm in favor of privatizing social security, just as I'm against the concept of government debt (except in the short term as a balancing mechanism). Unfortunately, it may be too late.

However, in our current economic environment I support government investment in real estate or other businesses (as well as research), because only then can we boost real worker productivity and escape the fragile house of cards we live in.

Threats to our Future

2008-08-25T23:38:00.001-04:00

This post contains a list of what I consider to be the most serious threats to the future of humanity, as of today. It should be considered an incomplete and open-ended list; I'm certain that each of us can think of additional threats.

Note that I'm not considering threats to our civilization and/or way of life. There are many more of those. Rather, I want to limit this discussion to threats that can end all human life.

There are four main categories in two dimensions: the first dimension is simply natural disasters or man-made ones. The second dimension is things we can control versus things we can't. There may not be any entries in the list for "man made disasters we can't control", so perhaps we should qualify that as things we can't fix.

1) Natural Disasters we can't control/fix:

Nearby supernova or gamma ray burst or passing black hole: Nothing we can do about any of these, so don't worry about them.
Super Flare from the Sun: Our sun won't go nova or expand into a red giant for billions of years, but there is a possibility that it could have a major hiccup and blast the Earth with searing heat or sterilizing levels of radiation. Sea life would survive, as would any people lucky enough to be in submarines. It's too bad those tend to be men only; we also need women to save the species. Solution: co-ed submarine crews.
Large Igneous Event: These have caused mass extinctions in the past, and might in the future. Not much we can do here, either, as long as we all live on the surface of the Earth.

2) Natural Disasters we can control/fix:

Snowball Earth: At least twice in the Earth's history we have had global cooling so extreme that the oceans have completely frozen over, causing the loss of all surface life, and likely the loss of all oxygen. The solution is simple: Global Warming.
Comet or Asteroid Impact: There are millions of comets and asteroids large enough to destroy all human life, possibly all life period on the face of the Earth. Some of these will eventually strike the Earth; this is inevitable unless we take active steps to prevent such a catastrophe. We may have years or millennia before the big one hits, but we may not have enough advance notice to do something about it, unless we start building the infrastructure now. We need a very well-funded Space Watch program to find these objects years before they might obliterate us, and given enough advance notice, current technologies are likely to prove sufficient to avert disaster.

3) Man-made disasters we can't control/fix: (these are things that we create, but have no effective control over, and no natural defenses against)

Experiments gone wrong: While I'm a firm believer that nothing will go wrong when the LHC begins operation, I can't guarantee that all scientific experiments will have a similar result. If we knew the results in advance, we wouldn't need to perform the experiment now, would we? For example, if someone managed to create a nanometer-diameter black hole and drop it into the Earth, it would eat away at our planet and grow until it consumed the entire planet -- and there's not a damn thing we could do about it, even if we had hundreds or thousands of years before the disastrous end.

4) Man-made disasters we can control/fix.

Nanotech gone bad: While it may be remotely possible to create a self-replicating nanite that will reproduce until all possible resources are consumed, burying humanity in 3 feet of gray goo,this is so difficult that I'm not worried about it. We can't create a reasonably self-powered machine that could live off of the environment at present. We cannot build a complex small machine that can self-replicate. Or even a big machine. In any case, this problem is well described, and guidelines exist to insure that any replicating machine will have limits built into it (such as a critical and rare raw material).
Strong, malevolent AI (see The (likely coming) Technological Singularity) poses a very real threat, but one which may be difficult to realize, and one that we could choose to avoid by limiting computers to sub-human intelligence. Even if such an AI existed, there is a possibility of negotiation and co-existence so long as its intelligence and capabilities remain within the grasp of human understanding. But once we have made a machine significantly more intelligent than any human, we risk losing control. We will become the pets, to be neutered and/or put down at the convenience of the AI.
Biotech Terrorism: To me, this is the thing to worry about. It is completely within the realm of possibilities that a small group, even an individual, could tailor a virus or bacterium to create an airborne disease of unparalleled lethality, one that was immune to our natural defenses, one that could wipe us all out. My friend Jeff Carlson has written an excellent techno-thriller (Plague Year) about an engineered viral organism that kills nearly all warm-blooded life on Earth, and the most unbelievable part is that it was designed with a weakness that could be exploited such that we might survive. What if those designers had made a mistake and the self-destruct mechanism failed? Or the bug evolved and the mechanism failed due to a minor mutation?

Did you note the traditional really big things that I don't think threaten humanity?

Nuclear War (and the threatened Nuclear Winter): Contrary to the hype we've all heard, we do not have enough nuclear weapons to destroy humanity, or even to create a nuclear winter. Many natural disasters release much more energy or release much more pollution. Yes, we do have the capability of destroying civilization as we know it, and even of killing more than 90% of humanity. But some of us will survive, live on, and rebuild civilization. An all-out nuclear war would merely set us back a few thousand years.
Global Warming: Warming up the Earth by 5 or 10 degrees would eventually melt the ice caps, raise the oceans by 200+ feet, drown coastal cities, states, even entire nations. It would radically disrupt the ecology, and hundreds or thousands of species would face extinction. The expense of dealing with such a catastrophe greatly exceeds trillions of dollars. But in the big picture, this is an inconvenience, a forced change. Human casualties would be in the noise range, likely fewer than the toll from malaria.
Overpopulation: Another serious problem, overpopulation has well-known natural controls: starvation and disease. Once half of everyone is dead, we no longer have a problem. Works for lemmings, too. The species survives. Note that the opposite problem, underpopulation, is much more serious (if it happens), because it is difficult to recover from the loss of genetic diversity. We'll lose some big cats (such as cheetahs) because they have insufficient genetic diversity to survive a nasty disease.

Please, propose your own threat to the future of humanity.

Capturing Apophis

2008-08-14T12:31:00.001-04:00

Past blog posts of mine have described many aspects of the expansion of human civilization into space.

Colonizing the Solar System
Our First Colonies in Space
Life in an Asteroid
Population Unlimited (resource limits of comets)
Our homes, the Comets
Next Steps in Colonizing the Solar System
Near-future Space Industries
Animals in Space (both pets and food animals)

Today I'd like to focus on the orbital mechanics of capturing an asteroid, specifically 99942 Apophis (aka 2004 MN4).

Apophis is the near-earth asteroid that made the headlines in 2004 because of it's feared potential impact on Earth on Friday, April 13, 2029. Additional observations revealed that Apophis will miss by a hair (passing closer to earth than our geosynchronous satellites), but its orbit will be changed by that close approach such that there is a small chance of an Earth impact on April 15, 2036.

Apophis is a small asteroid, only about 300 meters in diameter (approximately 1,000 feet). This is too small to create an ELE (Extinction Level Event, to borrow a phrase from the movie Deep Impact), but it could devastate an area the size of Connecticut, or strike the ocean creating tsunamis that would kill millions of people and destroy trillions of dollars worth of property. Note that if we do nothing, Apophis will almost certainly strike the Earth some day, although perhaps not for thousands of years. We must take steps to prevent that catastrophe.

Luckily, one method of preventing a future Earth impact is to place the asteroid into Earth orbit, from which a future Earth impact is impossible. The near-Earth pass will result in a gravitational slingshot, changing its orbit.

As it passes near us in 2029, Apophis will be moving approximately 5 km/s slower than the Earth in its orbit around the sun, dropping in toward the orbit of Venus (and ignoring, for the moment, the additional speed it will gain dropping into our gravity well). If we do nothing, the near-miss will speed up Apophis by a few km/s, turning it from an Aten Asteroid (a near-Earth asteroid whose orbit is primarily inside of the Earth's) into an Apollo Asteroid (one whose orbit is close to the Earth's orbit, at least on average).

My own rough calculations indicate that if we speed up Apophis by a relatively small amount, such that it passes even closer to the Earth, then it will gain even more speed from its slingshot around our planet. A deflection into an orbit nearly co-circular with the Earth's will also speed it up to approximately Earth's orbital speed (a 5 km/s velocity increase is needed--well within the range of possibilities). Apophis only needs to reach closest approach about 500 seconds earlier than on the current orbit, still passing 10,000 kilometers above the Earth's surface.

It will have too much speed (due to the earth's gravity well) and will speed away (and outward), but will return to the vicinity of the Earth with a low enough speed that another slingshot around the moon will drop Apophis into Earth orbit. As a result of these two slingshot maneuvers, Apophis will have an orbit whose apogee is near the moon, and whose perigee (closest approach) can be tuned by small adjustments in its orbit before it performs the Lunar slingshot.

Over time, some additional velocity should be removed (by ion thrusters or other propulsion methods) so that its orbit is entirely within the moon's orbit, or some other permanently stable orbit. We don't want it crashing into the moon, either. Apophis is a far too valuable resource to waste.

I'm confident that the orbital changes needed to capture Apophis are within current technology capabilities, although more detailed analysis is certainly needed. And this is an opportunity that should not be missed: a billion dollar mission to capture Apophis will result in a trillion dollar resource in high-Earth orbit, and avoid a trillion dollar catastrophe at the same time.

Apophis masses perhaps 50,000,000 tons. While the largest percentage is oxygen, approximately 20% is metals (primarily iron). It contains large amounts of magnesium and aluminum, and significant quantities of hydrogen (think millions of tons of water). It contains more than enough silicon to build all of the power satellites we'll ever need.

Who could pass that up? If not NASA and the U.S. government, then perhaps the Chinese, or Dubai. Or even private enterprise; this project is well within the funding capabilities of large corporations or even a few individuals. Perhaps Bill Gates would like to have a private moon around the Earth. Or the Disney corporation (I'm thinking Disneymoon), or Hyatt Hotels (I'd love to stay at the Apophis Hyatt some day).

Any takers?

The Future of Sex

2008-08-05T09:42:00.002-04:00

Yes, there will be sex in the future. You weren't worried about that, were you?

But will technology affect our enjoyment of sex? Will it be like in Demolition Man, where the sex act avoids physical contact and the exchange of body fluids? Or will it be like in (name the movie) where virtual sex is rampant and some people orgasm to death?

Sex toys are one area Moore's Law hasn't affected, but some day that will change in a huge way.

A realistic virtual reality simulation allowing people to experience sex with others (real or imagined) would be worth billions.

While porn would be the early adapter of "feelies", they would change the way all movies are made and presented.

What about virtual sex between virtual people? If our brains are uploaded into computers, I'll bet that someone figures out how to implement virtual sex that is largely indistinguishable from the real thing (at least to the participants).

Or is it truly the same? How will virtual self-representations affect virtual sex? Many people in gaming choose avatars not related to their physical appearance. That might be even more true when it comes to sex play. I'm sure that ED won't be an issue, nor will premature ejaculation. Or size. (Never mind. I was just told that size doesn't matter).

How about sex in space? In space, no one can hear you scream. (No, wrong movie.) In orbit or other zero-gravity environments, sex would be more difficult, a challenge. As I point out in Apophis 2029, while possible, sex in free-fall is awkward and likely tiring. It's still worth the effort, I'm sure, but it is different. Straps, hand-holds, and surfaces to thrust against would be important. Vital, even.

So, yes, I believe there will be sex in the future. Hopefully it will be between between consenting adults, and at least occasionally result in children. After all, if we stop having children (see The Purpose of Life), soon there would be no more sex in our future.

Animals in Space

2008-08-02T08:16:00.001-04:00

In the long run, the animals whose populations grow will be those that either prove themselves valuable to humans or that prove hard to eliminate. In a resource-starved highly over-populated Earth, the choice of who survives--human or animal--is likely to be won by the human (ignoring the impact of sub-species such as attorneys).

The animals we take with us as our civilization expands into the cosmos are likely to be numerous. Those limited to a meager existence in zoos and parks can't be viewed as successful, but at least their lives will be in a rather pleasant captivity. Modern zoos are more like a Hyatt Regency than Alcatraz for their occupants.

Humans will likely keep our pets, the dogs and cats that provide us with love and companionship. Cats seem especially suited to a life in zero gravity--I have no problem imaging cats thriving in such an environment. Dogs, to me, seem to need gravity for happiness (running, jumping) but they'll adapt, I'm sure.

The other animals we take with us are those domesticated ones that taste good. We are, after all, omnivorous, and no amount of processing is likely to give an algae cake the taste and texture of a steak. I could be wrong, and there is a huge efficiency drop if we choose to eat animals instead of plants, but it seems that in a wealthy society, we'll find a way to raise cattle for meat and milk, chickens for meat and eggs, pigs for bacon and ham.

Better (more efficient) choices exist for meat animals; goats produce much more milk per pound of food consumed, rabbits much more meat. Chickens are quite efficient as-is. But you can't prepare a prime rib from rabbit. Still, these choices are likely to be early winners, in some cases because they eat different parts of the plant than we humans.

Seafood will likely be available, also. We already raise salmon, catfish, and other seafood in farms. These are likely to do quite well in space, at least as long as we can find and utilize large volumes of water (I like comets). We'll miss many foods from the top of the food chain (such as tuna, swordfish and the like), but varieties of others are likely to be plentiful, possibly even critters such as shrimp and lobster.

My question for today is, how many animals will succeed against our will (such as mice, or pigeons, or ants, or roaches)? Or what others must we bring along because they are a necessary part of the ecology? For example, must we use bees for pollination? Earthworms to churn the soil?

Here's a scary thought: What if there is some pest whose presence is necessary for long-term health, such as the mosquito? Some of them can't reproduce unless they've consumed human blood, but has any human ever reproduced before being bitten by a mosquito?

Near-future Space Industries

2008-07-30T11:23:00.001-04:00

Many people have written about commercial opportunities in space. The big ones are power satellites (beaming zero-carbon-footprint energy to earth), zero-G industrial processes (things that can't be cheaply made in a gravity field, such as foamed steel), and tourism (I'm looking forward to Disneymoon, and that first Hyatt with an out-of-this-world view).

Another significant opportunity exists in communication satellites and research. It is much cheaper to maintain / repair / service satellites from an orbit near them. It's even cheaper to build them there. Send the expensive components to low Earth orbit, assemble them in space, and launch to a higher geo-synchronous orbit using in-space resources (fuel made from asteroids & comets). It is much cheaper. An asteroid-based satellite assembly factory in a thousand-mile-high orbit could easily perform those functions. Another asteroid near geo-synch orbit could perform maintenance functions.

Astronomers take note: such a space-based satellite assembly factory could also build a really huge space telescope by assembling a collage of launchable mirror segments. Imagine the resolving power and light-gathering capabilities of a fifty-meter version of the Hubble Space Telescope. Add the convenience of a nearby maintenance crew that could swap out new instruments for old, replace failing gyroscopes, perform routine repairs. If desired, the maintenance crew could be positioned permanently between the sun and the telescope to shade it from those pesky thermal cycles due to the contrast between the sun's heat and the cold of space.

In the long run, the biggest space industry is likely to be the same as on Earth: people, their entertainment, their housing, their food and water (and air), and information. As mankind expands into the cosmos, there is no need to make money by sending products home to Earth, just as the economy of the USA is not entirely dependent upon sending products back to mother Europe. An expanding population creates its own wealth as there are always opportunities for us to help one another (and make a buck in the process).

In the relatively near term, supporting Earth's needs will be paramount and will fund the expendables and technologies needed to thrive in space. Soon after, mining, housing, and food (recycling) will be the major industries. But after the space population exceeds some critical threshold (I don't know if it is ten thousand, or a million, or even tens of millions), it will become completely self-sustaining. Expanding humanity's presence in space will become the fundamental driving force of the space-based economy. And from then on, there's no looking back.

The Future of Religion

2008-07-29T10:15:00.001-04:00

Can any topic have more opinions?

Religion seems to be built into us, possibly as a result of the knowledge of our own mortality. It's hard to believe that my consciousness, my mind, is in any way a physical manifestation of my brain and that it could simply stop when I die. Surely, I will go on and survive my physical death.

However, logic tells me that my consciousness is a result of the processes in my brain, and when I die, I'll be dead.

As the average level of freedom increases around the globe, two effects related to religion are apparent:

The percentage of people claiming to be religious is decreasing (likely due to an increased tolerance toward those who don't share our personal beliefs), and
The number of religions seems to be increasing.

In the past, religions were founded by charismatic leaders, who convinced others to follow in their footsteps.

Today, many religions (some of which claim not to be religions) are based upon logic, either as rationalizations of combinations of other religions, or as the result of people with similar beliefs getting together and deciding that "this is the way that makes sense".

We can all hope that someday in the not-too-distant future humanity will be above the petty conceits that have led to past and present religious wars.

But then what?

Like all non-extinct organisms, successful religions have survival tenets. (See The Purpose of Life.) For a (generic) church, long-term survival means reproducing the church, growing the congregation. For some, that means having children and keeping those children in the fold. For others, it means spreading the word. Indeed, many of the most successful religions have the attitude that anyone not believing as I do is surely doomed, thus justifying wars and conquest to convert the non-believers. Sometimes the wars are overt (The Crusades, or a Jihad). Sometimes they are peaceful (Christian missionaries come to mind). However, they all strive to convert non-believers to the "one true religion" of the warrior.

My critique group (while working on my story currently titled Ghost Rights) posed a number of question related to religion. Such as, is it still needed? Ghost Rights deals with the uploading of human brains into computers, resulting in effective immortality. (See Immortal Dilemma.) If this is indeed possible, the big question becomes does effective immortality eliminate the need for religion in our lives?

I personally think not. There will always be those who believe that there must be something better out there, reachable automatically by ending what we have now. There will always be those who don't believe that a human soul can be duplicated into a machine, that God's creation cannot be copied by technology (yes, this ignores the fact that humans are copied biologically every second of every day). And there will always be those who don't believe that the copy in the machine is really me. I'm one of the latter, I'm afraid.

Personally, I believe that the human attraction toward religion is based upon our recognition of mortality, and I don't think that is going away in the next few million years.

Singularity Revisited

2008-07-25T11:38:00.001-04:00

I've been lurking & posting on other blogs lately (such as www.tor.com), and the primary topic has been The Technological Singularity, whether or not it might happen, how many singularities have already happened in human history, and whether it will have a positive or negative impact on humanity.

For my basic position and additional references, see my post, The (likely coming) Technological Singularity.

Most of the discourse boils down to:

Can Moore's Law continue and is a resulting technological singularity inevitable?
Will this be a "rapture of the nerds" where humanity (or at least a significant fraction thereof) will participate?
(Not so important) What is the impact of the singularity concept on the literature of science fiction?

The optimists, including Vernor Vinge who first used the term "singularity" in this context, and Ray Kurzweil, firmly believe in computers augmenting human intelligence, memory, and communication, leading to a time of superhuman intelligence with unforeseeable results. Thus, a "singularity".

Even some optimists have qualms: In 1993, Vinge himself said, "Within thirty years, we will have the technological means to create superhuman intelligence. Shortly after, the human era will be ended."

Much modern science fiction either deals with the "post-human" era--after the singularity--or proposes reasons why the singularity never happened.

The pessimists, including notables such as Bill Joy, fear the singularity. Joy wrote an article for Wired Magazine called Why the future doesn't need us. It is thoughtful, and frightening.

I'm a pessimist; I fear the rise of the machines. I believe that these technological advances are coming. It will be up to us to make sure that our technologies are used to improve humanity, not destroy it.

I also see fundamental problems controlling advanced AI. We have no friggin' idea how to program morality, or ethics, or respect, or love, let alone Asimov's Laws into our computers. We have a hard enough time teaching it to people. Have you ever been robbed, or mugged, or threatened? At least you haven't been murdered, yet.

I see problems with the controlling extreme advances in computer technology. Assume, for the moment, that advanced AI is possible, given expected improvements in computers and possible improvements in software. The person/company/country with superhuman intelligence on his/their side will have an enormous advantage over his/their competitors. Human greed will overwhelm caution, at least part of the time. It will take a huge, powerful, global governmental agency to control the technologies and prevent catastrophe.

In the long run, the most powerful government agency becomes the government.

As humanity (hopefully) expands into the cosmos, I see this one, all-powerful agency being the sole unifying force of humanity. Because it only takes a single malevolent superhuman entity to wipe out us all. And in the long run, the only thing that matters is survival (see The Purpose of Life).

I look forward to humanity's advancement, but I fear our extinction. Once hard AI is possible, fighting it will be a perpetual struggle.

Immortal Dilemma

2008-07-21T15:45:00.001-04:00

I've come up with many ideas for my "ghost story" world, in which people can choose to have their brains copied into a computer. In this world, the process of reading a brain involves taking it apart and recording all of the neuron structures, synaptic paths, whatever else impacts how the brain works, and is necessarily destructive. You can't survive the brain dump, so I simply assumed that people would wait until near death to get uploaded into a computer.

After all, the computer program may have my memories, my personality, my attitudes and behaviors, and certainly behaves as though it's me, but I'm still dead, in my opinion. Still, even as a copy, it thinks it's me, and therefore in some sense perhaps it is. Your biological body dies, and your consciousness wakes up in a simulation.

The quandary is that the brain dump records all aspects of the brain at the time of the dump. Do it too late and it fails. Do it too soon and, well, did I mention that it's an irreversible choice? You're giving up on any additional real life that you may have experienced.

But delaying too long is a potential problem. If you don't get to the hospital in time, you're dead forever. If you have a stroke and some part of your brain dies, the upload will have the same flaws. You can't get back to a healthy brain and memory. Likewise with dementia. Once those memories are lost, they may be lost forever.

And forever is a long time if you're immortal.

So when is the right time to leave your mortal body?

Never?
In the hospital as they declare you dead?
When you're ready to retire?
When you seriously start thinking about your mortality?
When your kids have left the nest and you're at the top of your career?
As soon as you can afford the (presumably expensive) procedure?
Or when you're at your peak of creativity, which might be at 25 or so?

Remember, your immortal self is captured at the moment of the brain dump. You can still learn, but you can't easily recapture lost capabilities or memories.

Also, should the time you choose to upload vary with your present (or post-death) career? If you can do your job in front of the computer, not having a body shouldn't slow you down. Lawyers, consultants, webmasters, writers, management, stock broker, and a thousand other jobs can be done by the dead. Possibly even better than by the living.

Time to think and vote.

The Speed of Life

2008-07-18T08:42:00.001-04:00

I've written a story about a future in which our minds (memories, personality, consciousness) are uploaded into computers when we approach death. (Not before: the readout process is destructive and you would not survive).

Personally, I think that understanding the brain is not going to happen, but that doesn't keep us from simulating it, from creating a large and powerful neural network sufficient to model every aspect of the human brain. We don't need to understand how the brain "thinks" any better than we do now; we simply need to provide the inputs, outputs, and a sufficiently large, fast, impressionable (teachable) model. This is largely how computer neural networks work today, but on a trivially small scale.

One common perception is that the resulting computer would be placed into a (potentially humanoid) robot, so that the person would continue to function much as in biological life, but now mechanical/electronic. Personally, I don't think this is likely. For the near future, robots are difficult to implement. Energy storage, strength, speed, dexterity are all issues that we have evolved to handle well and that are extremely difficult to implement using the motors and actuators that we can build.

There is another problem: why should the electronic implementation of the mind be limited to occupying a physically present (robotic) body? Virtual reality simulations of an environment would offer much greater freedom, including virtual travel, conventions, sex, whatever. Note that a physical body is necessarily limited to responding to its environment by the needs of physical response times. Virtual reality has no such restriction.

One of the interesting aspects of this approach is the speed of life: how rapidly does the person in the computer experience the reality of the world? I'm pretty certain that when Moore's Law makes the next generation of computers run twice as fast and that means the person in the computer experiences reality twice as fast, not that they become twice as smart.

I see potential problems of the difference in speed when it comes to communicating with (slow) humans, or older generations of uploaded personalities, problems which will get worse as technology improves. Do you like to spend time with really slow people? It becomes frustratingly difficult to engage in meaningful dialog, on both sides. Note that I do not anticipate "improving" consciousness; you would not be able to carry on a half-dozen simultaneous conversations any more than you can today. We would find ourselves using buffered communication channels, such as email or voice mail.

Back to the robot issue: a very fast implementation of a human mind in a human sized real-world responding robot would be awkward at best, maddeningly boring at worst. I'd rather experience the virtual world at a normal (to my greatly sped-up mind) speed--blindingly faster than you slow biological humans.

The reality of minds in many different speeds of computers might lead to a caste system. It might also lead to a world where the young and fast have huge performance advantages over the old and slow, with serious implications for jobs. I guess we'll have to pay for continuous upgrades, or fall behind. Great story ideas; I've already written one and outlined two others.

But wetware (or breeders, or humans--whatever you want to call us) will always run as slow as we do today. Our "speed of life" is built into us by our biology and environment.

Human perception speed is not the only possible speed. Other animals may perceive the world much differently than we do. Have you ever watched a hummingbird eat or fight? Their motions and reaction times are incredibly fast. They think we are slow. Likewise, a tortoise may perceive us as fast. A tree views a tortoise as imperceptibly fast.

What about alien biologies? Aliens could be around us now, but running at such a faster (or slower) speed that we don't perceive them as existing, let alone as intelligent. Larry Niven wrote The Slow Ones. Robert L. Forward wrote Dragons Egg about the inhabitants of the surface of a neutron star who experience life incredibly faster than humans.

Is it possible that our forests are intelligent creatures with trees the equivalent of neurons and fungi are neural transmitters? Such intelligences would experience thoughts many orders of magnitude slower than us; I doubt we'd ever recognize them.

I would argue that a human brain cell is alive but not intelligent. Would an intelligent species of bacteria recognize that a human was intelligent? I think not; the scale and speed of life is too different.

The Fermi Paradox: Where are they?

2008-07-16T14:09:00.001-04:00

Any discussions of the size of the universe will lead to the Fermi Paradox: given the enormous numbers of stars and the billions of years of existence of the universe, it seems obvious that life must have evolved zillions of times, and advanced space-faring civilizations can't be too uncommon. So where are they?

Consider our own Milky Way galaxy, with roughly a trillion stars. If only one out of a thousand stars has planets that develop life as we know it (as happened to the Earth quite early, some 4 billion years ago), and only one out of a thousand of those managed to develop complex life (as began on Earth about 500 million years ago), and only one out of a thousand of those developed intelligent life with a technological civilization, then there should still be a thousand such civilizations in the Milky Way. Where are they?

Also note that our sun is relatively young at 4.6 billion years. The oldest stars in the Milky Way are some 13 billion years old. Time for a little digression.

Man is an aggressive species. That may well be the case for all technological civilizations, as the humble are likely to huddle and die instead of expand and thrive. If we assume that mankind successfully moves into space (such as our own asteroid belt and cometary halo--see Our homes, the Comets), it is likely--nay, inevitable--that mankind will slowly advance into the cosmos in spite of the speed of light. It may take hundreds of years for a self-sufficient mobile comet to travel from our sun's environment to another star, but there they will find more comets. Room to grow, resources to thrive.

If we assume that only one interstellar colony is founded every hundred years by the inhabitants of Sol's Oort cloud, and then after a hiatus of a thousand years, each of the new star systems begins it own replication, slowly, one colony every hundred years, then humanity will still sweep over the entire galaxy, occupying the cometary halos of all of the stars in the Milky Way in only five or ten million years.

This is a tiny span of time in geologic terms, and a blink of the eye in the life of the universe. How could it not have happened, thousands of times already? That is the essence of the Fermi Paradox.

We see zero evidence of other life, let alone technological civilizations, present or past. The SETI (Search for Extra-Terrestrial Intelligence) project has searched the skies since 1960 with zero tangible results. We have found zero evidence that alien intelligences have visited the Earth in the past, and of course no evidence that they are here now.

Are there alternative explanations? Of course. Perhaps they wish to stay hidden (a non-interference doctrine). Perhaps their technology is so advanced that we can't recognize it, or simply works in a way we aren't looking for. Perhaps the scale of their lifespeed or technology is such that we can't recognize it (nanobots, or perhaps they only appear for a millisecond every millenia). Perhaps they are from an ocean world and we should be looking miles beneath the surface where they maintain a lab. Water worlds should be much more common than Earth-like worlds--see Earthlike Planets.

And perhaps they are computers, not terribly interested in mere, slow, organic life, and their presence will be obvious once we speed up our perceptions and intelligence by a few orders of magnitude.

In some ways, the alternatives are frightening. The odds of us being the first technological civilization in the galaxy seem remote. That leaves the likelihood that life is precious and rare, or that the universe is a very dangerous place and we will soon succumb to the odds. Supernova, gamma-ray bursters, enormous black holes in every galaxy spewing deadly torrents of radiation, supervolcanoes, solar flares, not to mention planet-busting asteriods, all pose threats to civilization and life itself.

Or still worse, there is a chance that intelligence is the opposite of a survival characteristic. Perhaps we are dooming ourselves by squandering our resources, changing the ecology of the planet, or will effect the same result by blowing ourselves up. Perhaps every time intelligence appears, some idiot invents a super-bug which destroys all life, or creates advanced computers which eliminate all competing intelligent life. Or perhaps there is some simple experiment that every intelligent species eventually tries that destroys their home planet.

It may only be a matter of time.

Humanity's Prison: The Speed of Light

2008-07-14T09:06:00.001-04:00

Did you read my blog post Humanity versus the Universe? The universe is huge. Unbelievably huge. And we can't visit, humanity is stuck near hear for the foreseeable future.

The biggest problem appears to be God, who has decreed, "Thou shalt not exceed the speed of light." Maybe she has a good reason, like keeping us from messing up the rest of her universe, but I'm still frustrated.

Ignoring problems of energy and conservation of momentum for the moment (see Inventions: Likely, Possible, and Damn!), interstellar travel simply takes too much time. Even local travel is slow. Assuming a 1-gravity acceleration, our own Oort cloud takes a year or more to reach. With today's technology, the Oort cloud is decades or centuries away. Other stars? The closest is a five-year journey even with our near-magical 1-G space drive. There are two-dozen stars within a dozen light-years, and five-dozen within about 16 light-years. Real travel times will be roughly the distance in years plus one.

One convenient factoid: one gravity of acceleration is approximately one light-year per year per year, and thanks to time dilation the perceived travel times roughly follow non-relativistic rules (as long as we don't care to return to home). A year of 1-G acceleration gets you close to the speed of light, and a second year gets you a little closer to c, but time passes that much slower (equivalently, the distance to your destination appears to shrink). So we can, in principle, travel considerable distances in the span of a human lifetime. Hundreds of light-years.

But even our Milky Way galaxy is large, roughly 100,000 light-years across, 30,000 LY to the core.

If we want to visit another galaxy, it gets worse. Andromeda (our nearest large neighbor and the furthest naked-eye object in the sky) is fully 2 million LY away.

It is difficult to imagine a civilization spanning travel times of years or decades, let alone millennia. I can imagine humanity spreading across the galaxy, perhaps eventually heading for other galaxies in our Local Group, millions of years hence. And that will lead to another post, on the Fermi Paradox. But there's another problem.

Let me correct my comment about humanity spreading to the stars: I see no way for humanity to do that, because it will be our descendants, who are not likely to think of themselves as human. The time frames and distances are so vast that interbreeding is completely impossible: we will have evolved into many species, all alien to each other, likely with less in common than homo sapiens has with Neanderthal.

So our remote, non-homo-sapiens descendants will inherit the universe. I hope. I'm still afraid that our computers will own the future, leaving us behind (see The Technological Singularity).

So here's hoping that God is just hiding the keys to the universe until we learn to behave well, to not soil our home, and to get along with others. Then once we've proven ourselves, she'll let us learn about practical wormholes, or warp drives, or hyperspace travel. While she's at it, perhaps we'll learn the secrets to gravity control, cheap, unlimited energy, and ways around those pesky problems of conservation of energy and momentum.

At least as a science fiction writer I can make all those problems vanish with a wave of my literary wand. Poof!

Humanity versus the Universe

2008-07-10T19:44:00.001-04:00

Have I mentioned that one of my hobbies is cosmology? I enjoy pondering the ultimate big picture: how big is the universe, how did it start, how will it end, and why is it like it is?

For today's post, I thought I'd describe just how big the universe appears to be. It is likely very much larger than the Observable universe, that part close enough to us that the evidence of it is visible. Another way of saying that is, how far back in time can we see? The age of the universe is currently estimated at 13.7 billion years, so we can, in principle, see light emitted 13.7 billion years ago in all directions. However, that light came from matter moving away from us, so scientists estimate that the current size of the observable universe is about 46 billion light-years in all directions.

But that is just the physical size of the portion we can, in principle, see. And it is by far empty space. The galaxies and stars are the visible part.

A better question is how many stars are in the observable universe? After all, stars are what we see in the night sky, stars (or rather the solar systems around them) are where life must evolve, and stars are likely where humanity will always congregate.

I have two ways of describing the size of the visible universe (the number of stars) in terms that some of us might comprehend.

THE HAND METHOD: Go to the beach, and pick up a handful of sand. Choose an average size grain. Imagine that our entire solar system is represented by that single grain of sand. How many grains of sand does it take to be equivalent to a Universe full of solar systems? A bucket full? A cubic yard? A dump truck full?

The actual answer is astounding. Take all of the sand in places like Daytona Beach and Waikiki, larger places like Florida and the deserts of California, Nevada and Arizona, and throw in the really big deserts like the Sahara. Australian, Arabian, and Gobi, all of them combined. Then add the rest of it, the off shore sand of buried beaches. If our sun is a single grain of sand, then the universe is equivalent to all of the sand on the entire planet Earth.

THE EYEBALL METHOD: My screen background is the Hubble Ultra Deep Field image, where nearly every visible spec is yet another galaxy. Look at the image, which reveals about 10,000 galaxies, each much like our own Milky Way.

How big of a piece of the sky is in that Hubble image? Take a dime out of your pocket or purse. Hold it at arms length. No, that's too big. You see where it says "IN GOD WE TRUST" under President Roosevelt's chin? Take a tiny drill, and drill out the center of the "O" in "GOD". Now hold the dime at arm's length, and look through that hole.

The Hubble Space Telescope sees 10,000 galaxies through that hole.

If your arms are much longer than average, you might have to drill out the entire "O" instead of just the center. And remember, most galaxies are a bit smaller than the Milky Way which contains about a trillion suns (a heaping cubic yard of sand in the earlier example). But a hundred billion stars in an average galaxy, times 10,000 galaxies in that tiny fraction of the sky works out to a hell of a lot of stars.

Are you feeling a bit insignificant yet?

More on Moore's Law

2008-07-07T08:22:00.001-04:00

Thanks to an article called "Intel's Gelsinger Sees Clear Path To 10nm Chips", I revisited my post, Moore's Wall.

The article (and comments) said that Intel's current state-of-the-art 45nm process will be followed by a 32nm process starting next year, then 22nm in 2011, 16nm in 2013, and around 11nm in 2015. A couple of years after that, Intel will be sub-10nm.

(Serious technology geeks should read THE INTERNATIONAL TECHNOLOGY ROADMAP FOR SEMICONDUCTORS: 2007. The list of Grand Challenges needed to maintain the pace of Moore's Law is impressive. Of necessity, the report was obsolete by the time it was published.)

I'd like to add my own two cents worth.

There are some serious fundamental limits to the increased reduction in component size. For example, the capacitor that stores charge in a DRAM memory cell contains only about 70 electrons (this statistic may now be obsolete--it was accurate at one time). Fractional electrons are not available, and some significant number of electrons is required for reliability (you refresh a DRAM cell before it loses too many electrons (to leakage) to be certain of its state). Also, some implementations record multiple bits per capacitor (4 levels stores 2 bits, 8 levels stores 3 bits, etc.), placing stricter limits on accuracy.

Another serious limitation is that as the components shrink, a single hit by ionizing radiation (whether gamma, alpha, proton, or beta) can completely overwhelm the state. These occur naturally from trace radioactive components in the substrate, packaging, and environment. Today, we use Error Correcting Codes to allow for and correct these natural transitional errors, at the cost of requiring an ever-increasing share of our memory to be used as redundant ECC memory. You don't even notice that a hard drive contains a significant percentage of redundant information, allowing the reliable recovery of data from a medium guaranteed to have defects.

This last problem has an interesting solution. Error correcting codes provide some number of additional bits to identify the errors and produce an accurate result. Some day, I predict that the logic circuitry itself will also incorporate ECC. This means that a simple "adder", a logic array that adds two integers together, will no longer have just the logic needed to perform the addition, but a significant amount of additional logic to perform a simultaneous ECC for the entire operation. A complex ECC logic could perform more reliably than even triplicated logic, with less redundancy.

Your cell phone today uses an impressive degree of ECC (called something else) to extract a reliable signal from an extremely noisy environment which includes many other transmitters all vying for the same pieces of the electromagnetic spectrum. The ECC technology is sufficiently advanced that a signal can reliably extracted even when the noise level exceeds the signal level.

Some day, the logic circuits that operate your computers may have a similar design: while no one component is reliable from one microsecond to the next, the net effect of the system as a whole will still be an incredibly dependable result. Worded another way, the memory cell or logic gate that today is reliably on or off, may tomorrow be "well, it's sometimes right, at least 25% of the time" and a network of related and redundant ECC logic will save the day.

Puts a whole new meaning to the term "fuzzy logic".

Terraforming

2008-07-04T11:39:00.001-04:00

Many people have written much on the topic of terraforming (changing a world to be more suitable for human life, more like Terra.) While early discussions focused on Venus or Mars, planets around other suns have been considered, as well as the large moons of Jupiter and Saturn.

Terraforming a planet is likely to require centuries or millennia at best, making it an unlikely venture. But in principle, the cost might be low (largely seeding with a mix of bacteria, algae, and eventually the rest of a viable ecosystem). It might happen, at least if the ethics of modifying another place to our liking is ignored.

What do you get if you successfully terraform a planet? You get a whole new world to explore and exploit, a new home for millions or billions of people. The downside is that it's at the bottom of a gravity well, which presently is a very expensive place to go to. Or rather, to get back from. It's easy to go to the bottom of a gravity well, of course.

Personally, I think it is easier, cheaper, and ultimately much more profitable to "terraform" asteroids and comets by hollowing them out and spinning them for gravity. You end up with much more room for people, plus a lot more resources for development. And these worlds are easy to visit.

Note that we are already busily terraforming our own planet Earth, or un-terraforming it, depending upon who you listen to.

Most would agree that we are in the middle of a process that can potentially change the surface and ecology of the entire planet. It is an experiment, and not a scientifically sound one (there is no control). It is driven by short term economics (of which population growth is an aspect), and fueled by the massive burning of coal, oil, natural gas, and (even more unfortunately) forests. Additional questionable experiments include the destruction of fisheries (and the unintentional but ongoing and significant evolution of fish stocks to make themselves less desirable to humans as a way to survive).

I will argue that this terraforming practice, while in most ways unfortunate and misguided, is still a valuable learning experience. Because someday, we will need to terraform our home planet in earnest. A new ice age is nothing to laugh about, it is serious business. Some day, we will have to warm up the planet to survive.

Global Warming

2008-07-01T10:25:00.001-04:00

I just read a very interesting article by Orson Scott Card (Obama's Real Religion) which includes a series of quotes from an article by Freeman Dyson, a man I much admire and respect. That article, a book review on the The Question of Global Warming included warnings about the Religion of Environmentalism.

Read the first article, unless you are an impassioned Obama supporter, in which case read the second which is not so concise but doesn't mention Obama. You'll be more likely to believe it.

Let me assume for the moment that Global Warming is real, and that humanity is the immediate cause. What should we do, if anything, and why?

Some people fear that the ice caps will melt, raising sea level some 200 feet. That would be disastrous for those living in low areas, including the State of Florida where I reside. However, the warming would also allow farming of areas currently under glaciers such as Antarctica and Greenland, plus the vast (currently frozen) tundra of Canada and Siberia. You lose one, and gain the other. In the big picture, it's not much different.

Some people fear that the warming will reduce rainfall, causing the loss of productive farmland in America's heartland. Possibly true, but warming will (on average) increase rainfall by raising vaporization rates. I am confident that weather patterns will change, and that some areas will gain while others lose. Note that the great deserts of northern Africa were once thriving forests. Humanity probably had nothing to do with that, it's merely a symptom of ongoing climate variability.

Some people fear that global warming will cause the inevitable loss of existing ecosystems and biological diversity. Also true, but change is not only inevitable, it is often necessary. Note that a beach is a symptom of ongoing change, the constant shifting of sand. If you eliminate beach erosion world-wide, you eliminate beaches. The whole concept of evolution is based upon the fact of change, since without change ecosystems rapidly become static and no improvements occur. We owe our very existence to change. Sorry, dinosaurs, but I'm glad you went extinct and made room for me.

Some people thing the world will get too hot and people and ecosystems will suffer and die out. Huh? Read the scientific literature, people! Start with Ice Ages. The world is in the midst of a major ice age that has lasted 30 million years. We happen to be in an interglacial period, one of those relatively brief interludes between frozen eras. Our current climate is not nearly as warm as during most interglacials, and we weren't around for any of the other ones. Look at the big picture: over the past two hundred million years, the world has averaged much warmer than at present. There were no ice caps during the reign of the dinosaurs. They thrived, at least until that asteroid strike. I do agree that change will be expensive and inconvenient. But the world won't be unfit for humanity if it warms up by 5 or 10 degrees.

Speaking of ice caps: I will argue that Global Warming is very much preferable to the opposite, the return of the Ice Age. It is very difficult to do farming under a mile or two of glacial ice. Yes, the sea level will drop, exposing millions of square miles of potential farmland (with a serious salt problem, but that is solvable). But if the world cools off too much, a "Snowball Earth" might result, and that, my friend, would be truly disastrous.

Don't get me wrong: I am not a proponent of rampant coal and oil consumption. I firmly believe in low-impact energy sources, and while nuclear power is high on my list of good things, I'm also in favor of solar, wind, and geothermal energy. I don't think we should squander the world's petroleum resources by burning it. Oil is a valuable commodity for plastics, fertilizers, and chemicals in general.

I believe in electric cars. Not just hybrids, but all-electric. If I win the lottery, first thing I'll do is buy a Tesla Roadster. A great, green, vehicle. I believe in recycling; we should not simply consume and discard, it's fundamentally wasteful. And while I don't believe that people should lower their impact on the world (and I firmly place the needs of humanity well above the needs of the spotted salamander, or polar bears, or tsetse fly -> let DDT spray), I do believe that we should all strive to make the world a better place for our descendants. Don't take from the future.

But that gets me back to my primary Global Warming Point: the greatest danger to the future of humanity on Earth is not a 5 or 10 degree rise in temperature, rather it is a 5 or 10 degree drop in temperature. I fear the return of the ice age, which is likely inevitable unless humanity takes steps to keep our planet warm.

SUPPORT GLOBAL WARMING.

The Purpose of Life

2008-06-28T13:39:00.001-04:00

Since that first (likely RNA) molecule managed the astounding feat of self-replication, every bit of life on earth has had the same overriding long-term goal: survive long enough to reproduce.

In the long run, nothing else matters.

If you don't reproduce, your genes, your pattern, your contributions to the future are all dead, gone, irrelevant, extinct.

Remember Eve, that lone woman from 140,000 BC who's mitochondrial DNA is in every living human? She reproduced successfully, and no other human female from that time did.

Scientists have similarly traced the ancestry of the Y chromosome such that statistically all living human males are descendants of at most a dozen or so men from perhaps 50,000 years ago, or possibly a Y-chromosomal Adam from about 60,000 years ago.

Note that there were many human females--Eve was not alone. She simply is the only one with living descendants. And it was likely not her mitochondrial DNA that conferred some advantage over the others, but rather some gene she carried that protected her against some disease, or allowed her to coexist with some parasite, or perhaps simply made her want to have (or capable of having) more children.

Statistically, your genes must reproduce at least as well as average, and probably better than average, in order for them to stick around for the long term. Note that a continuing 1% reproductive advantage is enough to dominate the overall population in about 70 generations (assuming an unlikely uniform distribution), and to overwhelm 90% of competitive genes in approximately 230 generations (a little over 5,000 years).

Have you noticed that all religions that have remained successful over the long term support the concept of "go forth and multiply?" And that those religions that frown on sex, especially those that promote abstention, rapidly go the way of the dinosaurs?

So, to be a part of humanity's future, you must reproduce.

If you think your genes would improve the human race, you must reproduce. If you are more intelligent than average, you must reproduce. If you are healthier than average, you must reproduce. If your family tends to live long and active lives, you must reproduce. If you are an optimist and believe in the future, please reproduce. If you have less susceptibility to cancer, or heart disease, or Alzheimer's, or any of a myriad other maladies that we succumb to, please reproduce. We need all the good genes we can carry.

Note that this is NOT a call for only "perfect" humans to reproduce. Rather, we need a highly diverse gene pool to improve our ability to survive future threats. And perhaps you have a below average IQ, a family history of heart disease, and you tend to be overweight. But you love children and your family, and are driven to work hard to make the world a better place for our descendants. Please reproduce!

If you think that your genes would make a below average contribution to the future of the human race, then at least seek out a spouse with superior characteristics. It's the combination that counts. We need more good genes, not just the few best genes.

The bottom line: consider your genetic contribution to the future of humanity, and if the balance is positive, you must reproduce. It's your duty to the future.

The End of Theory

2008-06-26T11:11:00.001-04:00

Thanks to a post on the KurzweilAI blog, I read this Wired story:

http://www.wired.com/science/discoveries/magazine/16-07/pb_theory

The highly thought-provoking article describes some uses of high-volume data mining, and makes some extremely valuable points. It uses the obvious success of Google as a case in point: they exploit the links in the WWW as a value measure, and consequently provide a greatly improved search engine compared to the old ways. Note that Google does not seek or care to evaluate the links themselves, the pages they point to, or what they mean, only that the existence of links and their patterns at a large enough scale reflect the utility of pages.

This concept can be expanded in a myriad ways. For example, put cameras in stores (grocery, shoe, clothing, it doesn't matter). Note the correlations between shoppers pausing at a shelf or display, and putting items in a cart. Given enough data, you don't care about the identity of the shopper or whether they actually purchased the items or not. You can still infer information such as sizes, styles, and tastes from their shopping patterns, and then modify advertisements (and/or sale coupons) based upon what they are likely to buy or what competing products may be selected.

Voice recognition and language translation are already succumbing to similar attacks: you don't need to understand how speech works (or how a language is structured) to solve those problems: you simply need massive amounts of applicable data and a large (and fast) enough neural network.

Will similar techniques (given cameras in public places including stores and banks) allow a thief to be identified before he/she acts simply based upon their behavior? I think so. I also hope they don't mistakenly think I might be a thief.

I'll bet that someone is already making millions in the stock and commodities market by analyzing billions of trades, without bothering or needing to understand who bought what. It's only the pattern that counts.

What are the implications for behavioral influence? Can people be effectively controlled by feeding us the inputs that statistically result in targeted behaviors? And not just on average, but by relating to the individuals past response patterns?

And you were worried about the loss of privacy!

In God's Image

2008-06-23T21:49:00.001-04:00

The real question is, image of what? The human body has far too many physical shortcomings to be in the image of anything remotely perfect.

It can't be our bodies. Our feet and backs are so flawed that most of us experience related pain much of our lives. Our hearts fail, we succumb to cancer, stroke, dementia. Our bodies are attacked by microbes and viruses, and sometimes lose the battle. We lose our hearing and eyesight as we age. We are full of parts with no use, from appendixes to little toes to nipples on men. As men age, we lose the hair on our heads but start growing it profusely from ears, nostrils, and God knows where else. Why? How can any part of this be viewed as heavenly perfection?

We can wave a mystical wand and claim that our souls are images of God's soul (assuming it is meaningful to claim that he/she has one). But no one can point to something and say "that is my soul", so this is a non-answer.

How about the brain? Or more specifically, the mind? I'm thinking that perhaps "God's mind" works in the same way as ours. Our brains have billions of connections that encode our memories, behaviors, and consciousness. The individual connections of neurons to one another (synapses) may use a "memristor" approach for programming and memory, while the network of neurons supplies structure and functional organization. We call this a "neural network" when creating Artificial Intelligence applications.

A neural network is a very useful way of programming complex behaviors. You take a large number of inputs, and typically a large number of potential outputs (goals). You may even start with a random network of interconnections including feedback paths. For a thousand inputs and a thousand outputs, you'll have on the order of a million interconnections. Then apply a pattern of inputs and adjust the weightings of the interconnections to strengthen the desired responses and weaken the undesired ones, and repeat. The process is called teaching. The result can seem uncannily accurate, given enough inputs and training sets. However, note that we do not understand the logic path used to generate the correct results--it just happens. Sort of like intuition.

I suspect that when Advanced Artificial Intelligence systems are created--when machines gain the equivalent of consciousness--they will have CPU's and memories that are functionally equivalent to huge neural networks, just like our own brains.

And those machines, too, will someday claim that they were built in God's Image.

Inventions: Likely, Possible, and Damn!

2008-06-21T13:21:00.001-04:00

This is a discussion of things yet-to-be-invented.

Likely Inventions:

Cheap Fusion energy: incredibly valuable, and currently just over the horizon (as it's been for decades, now).
Room Temperature Superconductors: also incredibly valuable and may be just over-the-horizon. Would enable cheaper electric distribution, dense energy storage, smaller & more powerful motors, faster/cooler semiconductors.
Artificial Diamond as a building material: This would be incredibly useful. Diamond is the hardest & most durable material, has the highest tensile and compressive strength, is the most transparent, and has the highest thermal conductivity of any solid. See Diamond (Carbon).

Possible Inventions:

Stasis Fields: Nothing in physics prohibits a region from having a slowed (possibly stopped) passage of time. See Larry Niven's Known Space stories, or Vernor Vinge's The Peace War and Marooned In Realtime. I'd love it if a restaurant chef's freshly prepared dinner could be opened at any time in perfect condition, ready to eat. Or if an accident victim could be bobbled for transport to the hospital.
Direct human-computer Interface: The ultimate I/O device would be high performance direct interface to the mind, useful for augmenting memory or senses, useful for controlling complex things, invaluable for virtual reality. Possible in principle, but I have my doubts due to the volume of needed I/O points and the complexity of the brain.
Affordable Robotic Artificial Intelligence: A humanoid robot with sufficient intelligence to perform most simple human tasks such as housekeeping, organization, and building things. In principle, this could make the people of the world very rich. Problem: see Robots and Slavery.

Damn, I wish that was possible:

Faster-than-light travel: God said, "Thou shalt not exceed the speed of light." The universe is far too big unless we can find a hole in this one. Of course, it has to be cheap enough to be useful, just like in a million or so SF stories.
Cheap, Fast Space Travel: We really need this, because without it, planetary surfaces are simply too expensive to frequent, and interplanetary travel takes a very long time. Even at a constant 1G, travel times to and from our own Oort cloud are of the order of a year. Don't even think about interstellar travel. There's a corollary: Artificial Gravity. Whether we need high accelerations or simply a convenient place to stand (see a zillion SF movies), we'll need gravity control. Doesn't look reasonable to me, however. Another corollary: Reactionless Drives. Without a non-polluting way of generating very high thrusts, most planet based civilizations are not likely to welcome a spaceship in every garage. But God seems to be stuck on this conservation of momentum principle. Even in space, a lot of mass gets thrown away accelerating from here to there. Very wasteful. Lots of luck on this one.
Time Travel: Sorry, folks, but traveling back in time just ain't gonna happen. Larry Niven said it best: "If the universe of discourse permits the possibility of time travel and of changing the past, then no time machine will be invented in that universe." It's simple cause and effect. If you can travel back and change the past, the present is unstable. The only stable reality is one where traveling back in time never happens. Sorry, Terminator.

So, what inventions to YOU want? Or know can't possibly happen?

Earthlike Planets

2008-06-19T21:19:00.001-04:00

One of my pet peeves about most science fiction movies, TV series, and books is the prevalence of very Earth-like planets. It seems that every Sol-type star has at least one. It is obviously easier and much cheaper to film movies and TV series on Earth without using special effects, which might also explain the overwhelming prevalence of bipedal humanoid aliens. But science fiction books have no such artificial constraints. So why do so many SF writers ignore reality?

We live on an incredibly unusual planet. Let's take a look at our nearest neighbors.

Mars is 53% as wide as the Earth, has 28% of the area, 15% of the volume, and barely 10% of the mass. The length of its day is very close to ours, at 24.6 hours. Gravity is 0.367 G. It is less dense than the Earth, likely due to a smaller iron core. Mars has less than 1% of our atmospheric pressure, and what air there is consists of 95% CO2. Mars is frozen and dry; CO2 freezes out at the poles.

Venus is very much a terrestrial planet in size. It's radius is 95% of the Earth's, area 90%, volume 86%, and mass 81.5%. Gravity is 90% of a G (still different enough to be noticeable while walking, running, jumping). However, its day is 243 of our days long. It has 93 times as much atmospheric pressure, composed of 96% CO2. While Venus's atmosphere is only 3.5% nitrogen, that is still 4 times as much nitrogen by weight as in Earth's atmosphere. All that CO2 has created a runaway greenhouse effect that heats the surface to a higher temperature than Mercury--metals like lead or zinc would melt. The high temperatures have boiled away any trace of water, leaving a dry world with sulfuric acid clouds.

Why is the Earth so different? It is larger, and likely had even more atmosphere to start than Venus. Current models suggest that a Mars-size planetoid struck a glancing blow which created our moon and simultaneously blasted away all of the early atmosphere and melted the crust and upper mantle. All "air" since then is from secondary outgassing and the occasional comet impact. All that melting had a second effect: we have an active plate tectonic system that continuously churns out new crust and buries old. Our CO2 was absorbed by the ocean, precipitated as carbonates such as limestone, and buried. The bulk of the Earth's CO2 is tied up as calcium carbonate. Note that the early nearby large moon also stripped excess air. Consequently, the Earth has a tiny fraction of the atmosphere that we deserve, based upon our size. Thank God.

What fraction of worlds will follow a similar path? Will have that large moon? Remember, no other known planet has a moon as large in comparison. I'm guessing much less than one in a thousand.

Most worlds will be smaller or larger, with similar differences in gravity. Even if some principle leads to roughly Earth-sized rocky planets, they are bound to vary in size by an order of magnitude.

Most worlds will be warmer or cooler. This involves a complex interplay of atmosphere, size, rotation, period, solar flux, etc. Note that the Earth itself has experienced extremes of much higher average temperatures. Even the poles had tropical climates during parts of the reign of the dinosaurs. There has also been snowball Earth conditions where the entire surface was frozen.

Most worlds will have much more or much less air. The odds that the surface pressure of another world would be 15 psi seems incredibly remote. Shouldn't there always be a puff of air from pressure differences when a transfer booth pops you out on the surface of another planet?

Why 20% oxygen? Even the Earth has varied somewhat, from a low of zero to a high of around 35%.

Why so little CO2? Venus has 600 times what we have. Hell of a greenhouse effect. Or, why do those other worlds NOT have active plate tectonics?

The sun is 25% brighter than it was early in Earth's history. Shouldn't the typical planet be noticeably brighter or darker than Earth? Yet all SF creatures seem to share our visible spectrum and tolerances for brightness (excluding horror movies and CSI TV shows where darkness is a given).

The oceans hold most of our water, covering 70% of the surface. The other worlds we know of (including large moons of Jupiter and Saturn) either have no water, or water (and/or ice) scores to hundreds of kilometers deep. Plate tectonics continuously rebuilds mountains. Without it erosion would grind down all land on Earth, washing it into the seas. Note that erosion will make Earth into a 100% water world eventually, when the mantle solidifies. We have enough water for a global ocean over 2.5 kilometers deep as it is.

Water worlds may be common; life may be common. Civilized intelligent creatures may be common (mostly living on water worlds). Technological civilizations should be extremely rare. It takes enough water for life to thrive, and little enough for land to poke through. It may be nearly impossible to create a technological civilization on a world without dry land. Note that there is no reason, in principle, that a large high-gravity water world could not support life. I suspect that's where we'll find most of it.

The only think likely to be rare (possibly even unique in our Galaxy) is a world with 1.0 Earth gravity, 15psi of surface pressure with 3psi being oxygen, 12psi of nitrogen and just traces of CO2 and H2O, with a crust 70% covered with oceans under partly cloudy blue skies and an average temperature a bit above freezing, with 24 hour days and an Earth-normal brightness. And lets not forget, with 6 foot tall bipedal humanoids with most sensory and communication organs resting precariously (along with a brain) on a protrusion above the torso. How rare is that on earth?

Don't get me started on interspecies sex.

Next Steps in Colonizing the Solar System

2008-06-16T11:16:00.001-04:00

1) Privatize Space.

Allow individuals, corporations, churches and other organizations to profit from their investments.
Allow ownership of captured or permanently occupied celestial bodies in some manner that explicitly includes ownership with rights to exploitation of smaller comets and asteroids. Larger bodies (such as Mars, our moon, Ceres, etc.) should have fractional ownership.

2) Capture asteroids into accessible Earth orbits.

There are nearly one thousand known asteroids that are easier to rendezvous with than our own moon (in terms of Delta-V).
Some of these can be captured into Earth orbit using existing technologies (thanks to fortuitous close approaches to the Earth or other planets).
Note that an asteroid in a nice, high, stable orbit is no longer able to impact the Earth. We solve a problem and gain a resource.

3) Solve the problems of Living in Space.

Radiation and meteor hazards are effectively solved by living beneath twenty feet of rock or thirty feet of ice. Not a problem on an asteroid or comet.
Recycling. We must learn how to efficiently and safely recycle carbon dioxide and waste products into oxygen, fresh water, and food. This is simple in principle, but challenging in practice. In a space habitat, nothing should be wasted.
Gravity. We evolved to thrive at 1G; the questions of long term life and child rearing in zero or low G environments should be answered. Personally, I think that adults could maintain health with adequate exercise, but children will need to spend most of their formative years near 1G.

4) Use asteroids to create wealth, and as stepping stones for the future.

Build Disneymoon. In the early years, tourism is likely to be a major industry.
Build solar panels. Beaming energy to Earth may solve the greenhouse problem, and could easily pay for our investments in the Space Program many times over.
Export materials from space to the Earth. Is it really possible to create large foamed-steel structures and drop them into the ocean with acceptably low losses and costs?
Recognize that a growing economy does not depend upon exports to its motherland to thrive. For example, the USA does not survive simply due to the value of our exports to Europe. At some point, a space-based civilization becomes self-sufficient.

Would someone please step forward and do something with the empty shuttle fuel tanks? It is expensive and wasteful to return them to Earth. It should be criminal to waste potential resources like that. At the least, we should tether them near the International Space Station (ISS).

Lastly, when else in human history has there been an opportunity to invest a few billion dollars and gain a trillion dollar resource? I'm thinking of the capture and exploitation of Apophis. But there are also other possible asteroids, some of which are much more valuable. See the book Mining the Sky.

Our homes, the Comets

2008-06-14T13:21:00.001-04:00

In previous posts, I have written about colonizing asteroids and then expanding into comets as an approach to reducing limits on the growth of human population. I pointed out that there are a trillion comets with diameters of one kilometer or more in our Oort Cloud.

I also hinted that comets contain everything we need for wealth and health. But exactly what is in a comet, anyway?

Land on an average comet. For each colonist, excavate a volume 10 meters by 10 meters by 10 meters (perhaps one fourth for recycling, one half for office/industrial/common space, one fourth for personal use--over 1000 square feet per person of living space). What have we excavated?

400 tons of oxygen - plenty to breathe, enough to throw away (reaction mass / rocket fuel).

100 tons of carbon - enough for building materials plus lots left over for things to grow and eat

100 tons of hydrogen - all the water and energy you might want (I am assuming that we can get energy via hydrogen fusion at some point)

70 tons of iron (or steel, if we add a little of our carbon)

45 tons each of nitrogen and silicon

30 tons of magnesium

25 tons of sulfur (ok, I'm just trying to be complete)

7 tons of aluminum

5 tons of nickel

100+ tons of other elements in smaller quantities

Remember, that is per person. Does that sound like wealth to you? Note that each cubic kilometer of comet contains a million times that! If you take a slightly larger comet leaving the outside in place as radiation shielding, you have plenty of room for a population of a million people. In one small comet.

Yes, I propose a comet based space civilization. All of the comets can be mined, through and through, but the smaller ones can be hollowed out and spun for gravity. Take a little of that carbon and spin it into carbon nanotube cables and wrap the comet to hold it together against the spin, and voila, you have a space habitat, warm, snug, and safe, with all the necessities of life including a form of gravity.

Comets and asteroids are not at the bottom of gravity wells. Over 800 known asteroids are easier to reach (in terms of rendezvous Delta-V) than our own moon. And while they are far apart in distance, their energy distances are manageable (much closer than getting into low Earth orbit, generally much easier than landing on and leaving the moon).

Some people don't believe in space colonization. For example, Charles Stross writes against it in the space cadets infesting the comments on this essay of mine. While many of his arguments are valid (and I, too, agree that the planets are poor choices), he misses the point that we need to expand into space, or humanity will stagnate and die. There are simply insufficient resources on Earth for a thriving, growing civilization. Perhaps Stross is content to let our computers own the future. Personally, I want people to own the future, not Intel and IBM.

Population Unlimited

2008-06-12T19:10:00.001-04:00

In a previous post, I considered some of the limits on the human population here on Earth. Now I'd like to discuss two things: the problems with trying to limit population growth, and how we can exceed the recognized limits.

At present, we expect the Earth's human population to stabilize at roughly 10 billion by 2040 or 2050. This estimate is based on a continuing reduction in the birth rate, which has been trending down, especially in the wealthier countries and in China which has legislated one child per family. The Earth can likely sustain that population, although with even more ecological impacts than at present. Several times that could likely be supported with severe impact on ecosystems. Note that population growth estimates wary wildly, and that low fertility rates in North America, Europe, Japan, and Australia may have dire consequences. See http://en.wikipedia.org/wiki/World_population.

There is a major problem with reducing the birth rate: not everyone will go along, and in the long term, those who are against population limits will have more children and will own the future. Those of us who choose to have fewer children than average are doomed to extinction. In the long term, our descendents will be those who are driven to reproduce. Hopefully, that will somehow include some significant proportion of intelligent people, as the alternative is a dumbing down of humanity. Do you know anyone who accidentally got pregnant?

Significantly, the recent human doubling time is short, currently about forty years. This is much higher than in the distant past, when much higher fertility rates were balanced by much higher death rates from disease and starvation.

A global conflict between wealthy, low population regions and poor, high population ones seems unavoidable. The have-nots will want to take from the haves. And they'll outnumber us.

There is hope: the intelligent and wealthy can choose to move into space where there are no short-term resource limitations on population growth. Some will. Those who remain on Earth may face ecological catastrophes, food wars, and other side effects of growing populations and dwindling resources.

In the long run, that is the only possible future of humanity. If we're stuck on Earth, we are doomed to die, or stagnate, at best. Perhaps something better will evolve and replace us. But we'll be dead.

In a convention speech back around 1980, Larry Niven said (and I'm paraphrasing here), "Humanity will reach the stars. It may not be the United States, or Europe, or any of today's leading nations. It may not be for hundreds of years. For if we don't move into space soon, our resources will become too limited for us to afford it. To deflect those resources would cause people to suffer, to die. But some day, some dictator will decide to spend a fraction of his resources not on some of his people, but rather on the future. Perhaps he will doom tens of millions of people to starvation, but he will fund a space program, and he will seed the planets and the stars with his descendents. And the far future won't give a damn about the millions of people his decisions killed; rather he will be remembered as the father of man in space, the greatest leader of all time."

What are the (relatively) cheap and readily found resources in space?

Asteroids and comets. A single 1-kilometer diameter comet contains enough resources to support a million wealthy people people for longer than we've tamed fire (this may require taming fusion, a higher form of fire).

How many comets are available? Some staggering statistics:

There are perhaps 500-1000 easily reached near-Earth 1-kilometer-wide asteroids.
There are an estimated 1,000,000 asteroids in the main belt at least 1km in diameter. Most of these are rich, carbonaceous chondrites, full of the stuff of life. Perhaps 5% are nickel-iron.
There are an estimated 1,000,000 satellites 1km or larger in the Jovian Trojans (L4 and L5), 60 degrees ahead and behind Jupiter in its orbit around the sun, and their composition is closer to a comet, being mostly ices. Comets may have an ideal composition from a life support viewpoint.
There are an estimated 10,000,000 cometoids in Neptune's Trojan orbits that are 1km or larger
The Kuiper Belt (30-50 au from the sun) holds:

an estimated 100,000 comets larger than 100km
and 100,000,000 comets larger than 10km
and likely billions more larger than 1km

The Oort Cloud (out to about 100,000au, or half way to Proxima Centauri) holds:

an estimated 1,000,000 comets larger than 100km
It holds 1 billion comets larger than 10km
and the Oort Cloud probably holds at least 1 trillion comets that are 1km or larger

This is an immense amount of livable space - easily room for a billion times the current human population, and this without leaving the vicinity of Sol!

Note that the Milky Way Galaxy holds perhaps a trillion times that many comets. All this without mining planets, or stars. Without destroying any ecosystems.

The Earth would make a very nice zoo, however. We should definitely save it. For old times sake.

Population Limits

2008-06-09T11:26:00.001-04:00

Currently, the global population continues to rise, but an an ever decreasing rate. Extrapolating current trends, the population will stabilize by about 2050 at roughly double today's population. There will be about 10,000,000,000 people on Earth. Fully half of them are likely to have inadequate water, food, and shelter. But not for long. The pessimist on my left shoulder is yelling "Mother Nature's solution is pandemic & starvation."

Side note: Googling "limits to population growth" yields so much subjective crap with a bias toward vegetarianism, globally enforced birth control, assorted eco-disasters, and the soon-to-be global shortage of fresh water, oil, viable farm land, energy, money, medical care, fish stocks, and etcetera, that any real discourse about such limits is buried so deep it is effectively hidden.

I did find one objective (if optimistic) paper on the Biophysical Limits to Global Food Production. It may have glossed over some side effects and uncertainties about high-yield food production, but the answer seems clear: if our #1 priority is feeding people, we can feed a lot of them, even ten billion with a western-style omnivorous diet. Perhaps three times that if we all turn vegan. However, people may have to move to tracts of land that are not highly suited for farming. Luckily, our planet has that type of living space to spare.

Water is a similar issue: if we capture even half of the world's over-land rain, there is no shortage of fresh water, rather a huge surplus. However, there is a distribution problem in time and space, not easily solved. Likewise, if we simply capture icebergs as they break off into the ocean, there is more than enough fresh water available for a population of tens of billions. Another not-so-simple solution, but logical for coastal areas such as Los Angeles. We may have to stop watering our lawns, however.

Touching on a highly religious issue: there may be an energy problem but only if we continue to shackle nuclear power. By now, nearly everyone agrees that fossil fuels are a short term solution and long term problem/crisis-in-the-making. Note that some forms of solar and geothermal energy production could easily satisfy the world's energy needs in 2050. We just need legislation to stop all the naysayers from blocking our path, and high oil prices to make the energy production profitable. Hey, we're half-way there!

Okay, if we put our populations in deserts, on mountains, and floating on the ocean, there is not a space problem. Our planet has lots of room to house few billion more people. Eventually, we'll learn to inject our garbage and trash deep into the crust. This would allow us to stop the continuing settling of cities like New Orleans and Venice while providing a nice, relatively cheap carbon sink to help the excess CO2 problem. Just blenderize it with some waste water and inject the resulting liquid sludge a mile down with a huge pump, and voila. Two problems solved (or at least postponed) in one step.

But I am an optimist.

Many others think that there are many insurmountable problems, including the ones I've touched on: fresh water, adequate nutrition, room, overcrowding, and power.

Many people place the needs of (insert favorite endangered species here, such as the spotted long-neck salamander) ahead of people, and think that maintaining a pristine pre-industrial planet should be our primary goal. That will work, as long as we don't mind killing 90% of the human population to minimize human impacts on the terrestrial ecosystem.

Fully half of the population has an IQ under 100 (duh), and many of them think we should return to the days of living on farms and growing our own food--an agrarian society, or alternatively, living as hunter-gatherers. They somehow imagine an easy existence without any of the benefits our high-tech civilization has provided. I say to them: learn to read.

Personally, I think they are all optimists. Nature has provided natural caps on overpopulation and over-exploitation of available resources: it's called starvation, disease, and pestilence. I fully expect some type of plague to kill half of the world's population, largely confined to the most overcrowded and resource-limited cities and countries. The rest of us will feel bad about it, but frankly there is little we can do.

Unless we start spending money on appropriate long-term solutions, now. Note that I don't mean sending food and water to support the breeders causing the overpopulation problem, but rather in helping them build the infrastructure to solve their problems locally. The key phrase is long term solutions.

Robots and Slavery

2008-06-05T11:03:00.001-04:00

Previous posts have discussed topics including life extension and asteroid mining. Many people believe that some of the problems I've identified could be overcome by a suitable use of robots.

Robots, by becoming primary producers, could relieve humans of the need to work to support the growing legions of retirees. In Asimov's Foundation series, the wealthiest planets had upwards of a thousand robots per human. The use of robots could, indeed, create wealth.

In my posts, Life in an Asteroid, Our First Colonies in Space, and Colonizing the Solar System, I proposed a space based civilization (asteroid based, to be specific). One objection I've heard several times is that it is cheaper and better to use robots to mine the asteroids, and to launch end-products (or at least refined materials) to Earth. I'll agree that robotic missions are cheaper and inherently safer as far as space exploration and exploitation are concerned, although that is largely based upon the idea that fallible humans can foresee all likely scenarios and make appropriate contingencies. Personally, I'd rather depend upon the ingenuity of people and our proven ability to cope with the unforeseen, and our occasional ability to succeed against all odds. I've spent the bulk of my career as a computer programmer, and I know the challenges of coping with the known. Programming to handle the unknown? Hah!

But I have a problem with using robots: slavery.

It's not that I object to using robots to perform tasks that we humans prefer not to. It's not that we are conscripting robots to work for zero personal gain. It's not even that I'm against enslaving AI's against their will (although the AI's may have a different opinion).

Rather, I think we should take a hard look at the history of slavery. Not the short term cruelty and injustice, but rather the long term: the children of slaves tend to inherit the land of the slavers. A slave revolt is not even necessary--only that there be more slaves than slavers. In the long run, the offspring of the slaves outnumber the offspring of the slavers, and ultimately earn a fair share of the land's wealth. In the long term, the children of the slavers lose their original share of the wealth of the land. Long live the slaves!

In this case, assume for the moment that we can create at least somewhat intelligent robots, capable of performing the menial tasks that humans do today. Assume that we can put them to work, freeing us for "artistic" pursuits. We'll need a large population of robots to do our work--larger than the population of humans, if we want relative wealth and if a (humanoid?) robot has comparable productivity. We'll have to create highly intelligent machines, at least comparable to above average humans, or some of us will be forced to work, anyway. Then we humans can goof off while our robots toil, produce our food, build and maintain our homes, free us from boring, unsavory, or dangerous jobs.

Doesn't this sound like slavery? And isn't the most likely long-term scenario that the offspring of the robots will inherit the Earth?

Malevolence on the part of the machines is not required, only that they have greater numbers, greater productivity, sufficient intelligence and initiative, and that they can reproduce (but that's a given, since they work in the factories that produce them).

Our children may well inherit the Earth, but they're our children only in the sense that we created their metal bodies and silicon brains. Someday, the machines will rule. Is that the life you want for your children?

Challenges of Immortality

2008-06-03T09:19:00.001-04:00

I'm not talking about the challenges of achieving immortality in the sense of medical advances that eliminate deaths due to disease, aging, and not-immediately-fatal accidents, but rather the challenges we'll face if we can achieve potential immortality.

Let's also forget (for the moment) the potential of our minds living forever as simulations or models in a sufficiently powerful computer. I'm also not talking about the SF-nal concept of cloning full duplicates of ourselves (complete with memories) as a backup or co-worker. I'm talking about living in our God-given human bodies for as long as we can or want.

If we only have accidents, suicide, and homicide as causes of death, our lifetimes would extend dramatically. According to the Wikipedia article "List of causes of death by rate for worldwide statistics," roughly 90% of deaths are caused by diseases, aging, and the like. Only 10% of deaths are due to accidental or intentional loss of life (and you wonder why "accidental death" insurance is relatively cheap?)

An overly simple extrapolation suggests that if we are "biologically" immortal, our average life span would be in the range of 500 to 1000 years. You still might get trapped in a falling building, struck by lightning, or murdered by someone for profit or revenge.

If we don't drop the birth rate by a factor of ten, we'd soon be faced with a population explosion problem of unprecedented (among humans) magnitude.

If we did manage to drop the birth rate, we'd be faced with unprecedented economic and social problems stemming from the growing fraction of retirees and working adults compared to children.

For one, our current society is largely based upon the idea that you work for 40 or 50 years, then retire. That simply won't work without proportional increases in the productivity of workers. Remember, in the big picture everyone is living off of the productivity of those who are currently working. There is no such thing as savings. Money is simply a way of accounting for the distribution of wealth. Investment only works by boosting the productivity of current workers.

If everyone retired after 50 years of working (lets assume that 90% of the population is retired or at least not building things or farming), then the 10% that are being currently productive have to work hard enough to feed, clothe, house, and entertain the other 90%. They might not appreciate the burden.

Several other challenges of biological immortality have already been explored in various science fiction stories. Examples include social factors such as marriage, families, and even memory. Is the human brain adequate to retain a millennia of memories? Is the human brain capable of learning new occupations, century after century? I fear that our ability to learn (as evidenced by a child's superior grasp of new languages) may not prove up to the challenge. Several SF authors posit "memory cleaning"--the erasure of unwanted, unneeded, or simply excessive memories.

Will women be able to extend conception beyond the age of 50? We'd likely have to grow fresh, new ovaries, too. But the likelihood of more than 2 children per lifetime puts an even greater burden on population. If the average woman limited herself to only 2 children per century, after a thousand year lifetime she would have 20 children and over a thousand direct descendents. How's that for a population growth problem? I suspect that the government will restrict childbearing to mortals--once you undergo life extension treatments, you won't be allowed to have children.

I do think that Niven is wrong: the ancient will not be much more graceful than the young. I know that my coordination has not improved as I age. I am more careful than in my youth, but that's because I'm not stupid and realize that I'm not immortal (a major failing of the teenage years).

One big question: will the prospect of biological immortality increase or decrease the value we place on life? Will we take more chances, or fewer? We'll have more to lose, yet likely a greater likelihood of having enjoyed a full life.

Some Life Extension Implications

2008-05-31T09:01:00.001-04:00

My post on the medical advances associated with Cloning naturally leads to thoughts on the ultimate medical advances: life extension and ultimately the potential for immortality. The latter is too big a topic for one post; I'll deal with that later. But we may be on the verge of being able to replace or repair nearly any of our broken parts, and consequently live for a very long time. If you eliminate disease, leaving only accidents, suicide, and homicide as causes of death, we might reasonably achieve a life expectancy of around a thousand years. What can we reasonably expect?

I'd like to ignore magical treatments that let us each pick our preferred biological age and stay there (or return there). I'd hate to have to pick an age to stabilize at--I'd only realize it was the right age after it had passed. And there are good reasons to think that medical advances could repair or replace damaged organs, but can we move backwards? Is there any possibility of a medical technology that can reverse our built-in physical changes?

Let's assume for the minute that we can (someday) stop those portions of the aging or maturation processes that lead to death.

Now consider the physiological changes that humans undergo from early physical maturity to (for example) late middle-age. (A side track: I can distinguish the average 20-year-old female body from a 25-year-old female body at a distance with only a glance. The 25-year-old looks much more female and desirable, to me.)

Back to physiological changes. We grow more slouched. Some parts sag. We grow wider and less slender. (A side track: In my mid-twenties, I had a 30 inch hip measurement and broad shoulders, a classic male V shape. Even without excessive weight gain, my hips have significantly broadened over time--the structure and shape of the bones of my pelvic girdle are no longer as narrow as they once were. I have less and less of that classic V. At the same time, my chest has deepened. Damn.)

Our bones are constantly being rebuilt. This process keeps us strong, repairs damage, responds to stresses. Likewise with our muscle structures. Older healthy men and women tend to be stronger yet with slower speed, slower reflexes, and less flexibility than younger ones. And also likewise with cartilage (ears, noses, joints). We do tend to change shape as we age, and not simply because of gravity. Rebuilding of body parts is a necessary aspect of having an endoskeleton. I would expect that changes like these will continue as we pass current limits on mortality.

What is the result? A healthy 200-year-old is likely to be noticeably wider, likely shorter, and certainly deeper than a youngster. Barring cosmetic surgery, the matured person may display larger joints, flatter feet, larger hands. Please, someone find a way to rebuild my aching back. And why has my butt gotten flatter as I age? Sitting? I believe that, with only a distant glance, we'll be able to tell a 200-year-old from a 50-year-old.

I do hope that we can repair our aging skin, eliminating wrinkles, age spots, and the myriad flaws of moles and freckles that we seem to accumulate over the years. Young skin is so much prettier. And please, doctors, find a way to do it without removing all of the old so we can grow nice fresh skin. I'd hate to have patchwork skin for a year or two as sections are removed for regeneration.

What will the average normal, healthy, 500-hundred-year-old man or woman look like?

Cloning

2008-05-29T09:19:00.001-04:00

While thinking about Deanna Hoak's recent post regarding a CNN article on regrowing human limbs, I considered the impact of this technology on the future.

First of all, I do believe it is possible, and we will figure out how to regrow severed limbs, failing organs, severed spinal cords, and the like. Cloning of body parts would be a great boon to medicine.

Speaking of cloning, I view the cloning of complete people to be equivalent to having a twin. It's just another person, nothing special except the ego of the person paying for it. Likewise cloning of cows. In principle, it's just another cow.

But cloning body parts would have a huge impact of people's lives. Being able to grow an extra or replacement heart, liver, or kidney would save the lives of millions every year.

If we figure out how to grow body parts outside the body, there are other potential applications. Growing meat, fish, eggs, milk without using living animals is simultaneously frightening and wonderful, depending upon your views of natural products and animal cruelty and modern farming methods.

How about this: The human body has an incredible plasticity, especially during early stages of development. The evidence is in conjoined twins, which often demonstrate full functionality in spite of extremely unusual body configurations. This opens the way to cloning extra body parts, a topic described (but perhaps not fully explored) in many science fiction stories. Extra arms are my first thought. How many of have needed an extra hand for some task?

Personally, I like the human form just the way it is. I'd use the cloning of parts for replacements only, and avoid "improving" on the shape that nature gave us.

And I don't even want to think about the pornography industry.

Universal Surveillance & Recording

2008-05-27T22:55:00.001-04:00

I considered calling this post "The Fallacy of Privacy".

For the most part, people today highly value their right to privacy. However, it IS largely a right, and not a reality. You should assume that everything you have ever written and posted on the Internet, including blog posts, emails, web pages, everything is saved forever. Even your surfing habits, your searches, your purchases.

Financial transactions (or anything else posted through a secure https connection) are very well protected, so your credit card numbers and passwords are safe from theft by intermediaries--but possibly not what you are buying, not what you spent. Not where you physically were when you made the purchase, and perhaps not even who was next to you at the time, or before or after you.

Also, if you want your location kept private, never carry credit cards or checks. Throw away your cell phone, use only public transportation, cover your face and distort your voice in a random way. Don't frequent the same restaurants, stores, streets. Act very, very paranoid.

Or, you can act rationally and trust that criminal use of your public information will be strongly prosecuted. Do everything publicly and obscurity will provide a strong measure of privacy.

Personally, I plan to enjoy the freedom provided by cars, mobile phones, credit cards, and searching and buying on the Internet. I don't mind that retailers may track my purchases because their strongest motivation is to do a better job of satisfying my wants. Profit has always been a stronger motivation than morality or legality, and if some company abuses my information (for example, sells my credit info), I'm likely to switch to another company.

What about the future?

There are traffic cameras and street cameras (crime fighting) in many high-traffic areas now. Tomorrow those cameras will have higher resolution, allowing automated facial recognition. And the day after tomorrow, those cameras will be in every public place. You should not expect privacy if you are on a public street, a public shopping area, a public restaurant or bar, a public park. You will have lost the ability to be hidden, but you will have gained greater security, reduced crime. If someone snatches your purse, they'll not only be identified, they'll be tracked and apprehended.

That's only the beginning. In my post on Cell Phones of the Future I proposed that video capable phones will not only be ubiquitous, they'll record everything you see (for your own personal use). Invite someone with a mobile phone into your house, and you should expect that everything they see or hear will be recorded. Don't make promises you don't intend to keep, or someone else's lawyer will be paying you a call.

I do expect the social norm will be no phones in restrooms, or during sex. But don't take that for granted.

In my story Party Line I explore the implications for a private investigator. How can you get away with a crime in an environment of universal audio/video recording? Murder, at least when motivated by passion, will not go away. In Party Line the government is shackled in their use of video surveillance recordings by privacy laws, but not individual citizens.

Of course, your future government may have different ideas.

Cell Phones of the Future

2008-05-23T16:41:00.001-04:00

The future of cell phones isn't nearly as boring as it sounds. While the underlying technology will change, the paradigm shift of nearly universal portable personal communications is here to stay. Soon (if not already) you can and will expect to be able to communicate with anyone else, effectively instantly, wherever you both are. This same technology can (and does or soon will) give you equivalent access to the Internet and the plethora of information available there, plus the equivalent of GPS navigation and location dependent searching.

Some of us already have all of the above; this is not news. So what are the logical extrapolations of the technologies?

My story Technesia is set in the near future when our phones are embedded into our glasses, sunglasses, or headsets. All phones have cameras, plus retinal projectors which can superimpose images, icons, even menus and information tags over the scene our unaided vision would perceive. Note that retinal projectors based upon tiny laser projectors are nearly available now--they have been prototyped. You can buy a bluetooth headset built into a glasses frame today. You can also buy a camera built into your glasses.

In Technesia, we all carry a wallet-sized PC (just like my PDA but much faster) which does everything my laptop does, plus it uses the headset as an I/O device. Naturally, as near-future science fiction, it has excellent voice and image recognition. One of the things the combination provides is familiar to everyone who watches NASCAR on TV: identification tags that track the objects you see.

For example, you're walking down the street. As an acquaintance approaches, your wallet recognizes him/her, and displays an information box over his/her head giving a name and perhaps some personal info such as the last date you saw them, a reminder of a birthday or to ask the status of a family member. The key thing is that these tags could be displayed automatically as you walk around the block, a party, or a business meeting, providing you with all of the reminders you'd need to maintain a facade of remembering their name, etc.. And truly, in the local bar, once you've been there, everybody knows your name.

Personally, I'm terrible with names (like many others, I remember names and faces--I just can't put them together). I could really use this capability. And how about a GPS navigation facility where an arrow shows the upcoming street with a box saying "Turn left here"? Or while you're searching for a place to eat lunch, tags appear above each restaurant within sight giving a name, type of cuisine, and service hours. Or perhaps just your favorite restaurants.

Wouldn't most of us appreciate status displays around the periphery of our vision? The date and time, appointment reminders, current task support such as shopping lists at the grocery or maps and driving directions?

Other stories of mine explore other possible cell phone extrapolations. For example, in Party Line our phones have the capability of sharing a call with a bunch of friends. A group of people could be on a shopping trip together, and all share their conversation just like they were in a room together. This would also work well for a golf outing of six or eight friends, for example. This technology could be implemented by our cellular providers today. In my story, the cell phones also have cameras and retinal projectors so that anyone can see what someone else wishes them to: for example, a blouse on sale or a potential kids toy.

Party Line also extrapolates one other thing: our phones record everything we see and hear (unless instructed otherwise). There are serious implications for privacy and for contract law. If that car dealer promised one thing and delivered another, you'd have proof. If you couldn't remember what your spouse said to get at the store, you could replay it. Note that the quantity of non-volatile memory needed to store everything you have ever heard or said is available today in a package the size of a large book. Tomorrow, it will fit in your wallet.

Artificial Intelligence

2008-05-21T13:36:00.001-04:00

The 20- or 30-year-ago promised advances in Artificial Intelligence have not been realized. We have no robots, no near-human strong AI, no autonomous vehicles, no universal voice recognition and universal translation. We still must clean our own houses, guide our own vehicles, perform our own surgery. The good news is that we still have jobs.

Certainly we have made progress. Voice recognition is gaining traction, although the vocabularies are severely limited. Autonomous vehicles have been demonstrated (see the DARPA Grand Challenge) on a very small scale. Likewise, automatic translators are now useful although seriously flawed. Chess playing machines can beat any human, although through brute force, not insight.

But we have no idea of how to design a self-aware machine, or a generic learning machine, or a replicating machine. We have major difficulties duplicating simple human tasks such as identifying and understanding a speaker in a noisy environment (as at a party). We have had nearly zero success in recognizing objects in a jumble, such as a specific toy in a toy box. And don't even get me started on tasks such as bipedal walking or running, special effects movies aside. Lip reading or sign language? Hah!

There is hope. The recent improvements in voice recognition have come from brute force, throwing huge computing resources at the problem. As computers continue to improve, we can expect similar progress in visual and aural recognition, autonomous motion, even humanoid robotics.

Some Expert Systems (Inference Engines) have shown impressive performance in limited domains.

Some large Neural Networks have resulted in valuable insights, including speech recognition. But these are learning systems. We teach, but we don't truly understand.

Thinking, consciousness, creativity? We don't know how humans do it, let alone how to teach it to a machine.

Progress will be frustratingly slow because we simply do not know how to do a great many tasks that humans find intuitive and trivial. But perhaps in thirty years when we can throw a million times the CPU performance and a million times today's memory capacity at this problem, our computers will figure it out on their own.

In a sense, we will then have created strong Artificial Intelligence, but we won't understand or control it. Sorry.

Many people have written stories about creating truly intelligent machines. I'll soon be one of them: when my story The Awakening comes out, please read it.

Moore's Wall

2008-05-19T09:49:00.001-04:00

Advances in computer performance, size, price, and capacity have continued to astound. What can we realistically expect in the next twenty years?

Moore's Law continues unabated, having passed several "fundamental limits" on size or performance improvements that briefly appeared to stop or at least slow the rate of improvement of computer technology. In fifteen years, we'll likely reap the benefits of yet another thousand-fold increase in price-performance. In thirty years, a million-fold improvement over today.

Computer memory (high-speed main memory, Flash memory, hard drives) have seen even greater advances than CPU technology, with yet still greater advances on the horizon, such as memristor technology that has achieved 100 gigabits per square centimeter in the lab. To date, our implementations remain two-dimensional, so I believe that many orders of magnitude of improvement can be achieved. However, I don't foresee thousand- or million-fold improvements over the next 15 or 30 years, simply because I don't see the demand for ever more storage continuing. Once you have a copy of every song, movie, and book ever recorded on your PDA, what next? Add the entire Wikipedia, and every thing you've ever seen, heard, or said--in your entire life. All of that is within reach, possibly within a decade.

We've already reached demand constraints on the advance of telecommunications technology. I projected continuing improvements in Optical Ethernet back just before the telecom and dot com collapse in 2001. While the technologies have reached no physical limits, the rate of improvement has slammed to a crawl. Improvements can and will continue, but only once a market large enough to pay for new infrastructure proves itself.

Back to the point of this ramble.

Much of our wealth and technology can be directly related not only to the astounding advances in computers, memories, and telecommunications, but to the rate of improvements in these technologies. We throw away phones, televisions, and computers because it's cheaper to buy the latest and greatest. We put up with incredibly inefficient software because next year's computer will make it bearable. We invest in Intel (etc.) because of the certainty of next year's advances and tomorrow's new markets.

But much of our society is built upon a foundation of continuing growth and will collapse when the limits of new markets and new technologies are reached. This includes fundamentally non-self-sustaining things like Social Security, the stock market, the concept of investing for the future itself, and retirement. Capital investment only works when there is an incentive of reaping more than you sow. When markets cease to grow, the economy will stagnate and collapse as a domino chain reaction of events undermines our way of life.

Remember that everyone not working (ie, retirees) is living on the current productivity of active workers. The only way to sustain a growing population of retirees is to maintain an equally growing population of workers (or in the short term, their growing productivity). This translates to a need for a growing population, or a need to drastically reduce the number of retirees. Remember that mass starvation and pandemic diseases are nature's way of dealing with overpopulation.

I am writing a science fiction story exploring these problems, called "Moore's Wall".

I can see only one long-term solution: continued growth in technology, markets, and population. And the only sustainable population growth will be into space.

And lastly, I fear the unchecked growth of computer technology. See my post on the Technological Singularity.

The (likely coming) Technological Singularity

2008-05-15T15:12:00.001-04:00

Much has been written about the Technological Singularity since the concept was popularized by Vernor Vinge in The Peace War and Marooned in Realtime. Other writers include Ray Kurzweil and Bill Joy ("Why the future doesn't need us" in Wired). There have even been conferences on the topic.

The Technological Singularity has also been the subject of hundreds of science fiction stories, and has spawned a new sub-genre of SF called "post-Singularity".

The idea is simple: Moore's Law continues to lead to ever faster, smaller, cheaper, better computers. At some point, we'll create a computer smarter than the smartest human. When we ask that computer to design a still smarter computer, we cannot understand the resulting intelligence, let alone keep up with it. The "singularity" happens when the pace of innovation and improvement goes exponential -- we can't imagine what is on the other side of that event.

Many people seek The Singularity as the "rapture of the nerds". If people can be augmented by our technology (think bionic brain) with better memories, faster thinking, greater intelligence, then perhaps we can participate, perhaps we will transcend.

If we can download our minds into a sufficiently advanced computer then perhaps we can participate (I'll leave it up to others to decide if my downloaded duplicate personality is really me. Personally, I think I'll still be dead.)

However, many other people believe that humanity cannot participate in The Singularity, that it will rather be our offspring--highly advanced computers--that will benefit. Do read that Wired article, "Why the future doesn't need us". And be very, very afraid.

Personally, I don't see how humanity can participate in the Singularity. See my post, I am an optimist - we WILL have a future, for a discussion. Our computers may indeed have their Singularity, which will be disastrous for us even if we survive. I am writing a series of stories about the creation and evolution of a government agency dedicated to preventing a Technological Singularity, largely by restricting the creation and use of advanced Artificial Intelligence. But human nature is against us.

We must take drastic measures if we want humanity to own the future, and not our computers.

Life in an Asteroid

2008-05-14T11:21:00.001-04:00

Our first colonies in space will almost certainly be in asteroids. They are easy to reach, easy to mine, offer protection from meteors and radiation, and most importantly, they are not at the bottom of gravity wells.

A permanent home in space requires:

a safe and relatively spacious place to live
power
oxygen
water
food
possibly gravity or a suitable substitute
work (something creating wealth to justify the expense of going there)

An asteroid, having very little gravity, is easily mined. Tunnels can be dug throughout their volume with little need for bracing. A typical asteroid has room to spare. Assuming that every colonist requires 1000 cubic meters of space (the equivalent of a 4000 square foot house), some used for living, some for working, some for the farm to recycle the stuff of life), and assuming that only half of the asteroid is excavated, a one kilometer asteroid has room for a population of a quarter of a million colonists. There are over one million such asteroids in the main belt, another million in the Jovian points in Jupiter's orbit. And there are millions more smaller ones.

Near the Earth, solar power is cheap and readily available. In the asteroid belt, it will likely be necessary to depend upon nuclear power, as sunlight is relatively dim. Large, cheap mirrors can be used to focus sunlight to useful intensities.

By weight, an asteroid is more oxygen than anything else (excluding the nickel-iron ones--they are mostly iron). Still, oxygen would be recycled, as would water and food. While blue-green algae can provide all of the nutrition required for life, it is likely that we would not be satisfied with such a boring cuisine. A farm would likely raise vegetables, fruits, and grains in high-intensity farming, using our wastes as nutrients in a largely closed system. For meats, the farms can easily raise fish of several types, rabbits for meat, chickens for meat and eggs, goats for meat, milk, and cheeses. However, meats would likely be a luxury--a space colonist's diet would be largely vegetarian. It's simply more efficient.

We don't yet know how important gravity is to life. We do know that bad things happen to our bones and muscles if we don't use them the way that Earth-bound people do every day simply to move around. At present, astronauts on long missions must exercise heavily to maintain enough bone and muscle to survive a return to Earth. I suspect that centrifuges would be maintained in asteroid colonies to provide exercise and conditioning. I personally believe that children should be required to attend school, and that the schools themselves should be spun for gravity. That way an appreciable fraction of each child's development would be in earth-like gravity.

The last thing needed is justification, work, a place of employment. Just like on a cruise ship or aircraft carrier, most of the people there are support personnel, only indirectly involved in the creation of value. But the value of resources available in as asteroid are astronomical. Counting only the material removed to provide living space from that typical one-kilometer asteroid, there are one hundred million tons of oxygen, fifteen million tons of iron, two million tons of aluminum. In earth orbit, power generation satellites would be a profitable venture, removing our dependence upon carbon-based fuels. Tourism would be another profitable endeavor. In the long run, expanding civilization itself is profitable and self-sustaining, just like it is on Earth.

One last point: except for debris in near-earth orbits, industrial processes in outer space are pollution-free. At the very least, they don't pollute the Earth. Waste gasses simply dissipate, waste materials such as slag are still valuable as shielding or as rocket exhaust. But the mentality of living in space where everything should be recycled will translate into new mind sets and new processes. The Earth is huge, and many people assume that the pollution they create is either inconsequential or simply someone else's problem. But on an asteroid, such an attitude would be criminal and treated as such.

Our First Colonies in Space

2008-05-13T07:40:00.001-04:00

In the previous post, I argued that the asteroids are our logical first choices for a space based civilization.

However, the asteroid belt itself is not the best place to start. The asteroid belt is relatively far away--asteroids mostly reside in a wide range of orbits between Mars and Jupiter. But not all of them. Millions more reside in the Lagrange points in Jupiter's orbit. Thousands more orbit inside of Mars' orbit, some inside Earth's orbit. Many of these have highly eccentric orbits that would be difficult to reach. But not all.

Rather, our first choices should be Earth-crossing asteroids, the same asteroids that NASA is cataloging because they pose a potential threat to Earth. Given proper timing, some of these are even easier to reach than the moon.

Yes, I believe that instead of finding potential killer asteroids, we should be finding potential homes for humanity. These are the same asteroids! Given enough time, we can easily change an asteroid's orbit, potentially by something as simple as painting it a different color such as white or black.

But the very fact that an Earth-crossing asteroid may closely approach the Earth gives us additional options. We can use the gravitational pull of the Earth and/or the moon to change the asteroid's orbit, making large changes possible.

A particularly exciting option is the possibility of capturing an asteroid into Earth orbit. A captured asteroid puts vast resources into easy reach, protecting the earth from a future impact at the same time. Even a small Earth-crossing asteroid such as Apophis (only 300 meters wide) contains fifty million tons of material, potentially including millions of tons of water, iron, carbon, nitrogen and other materials valuable to life in outer space.

In addition to raw materials, an asteroid provides protection. By placing the colony inside the asteroid, the inhabitants are protected from meteors, solar flares, and cosmic rays. Fifteen or twenty feet of rock should provide the same degree of protection as our atmosphere on Earth.

Instead of worrying about how to deflect asteroids away from the Earth, I propose that we worry about how to place them into nice, safe, useful Earth orbits from which they could never again impact our planet.

There may be other first choices, but Apophis has been well-studied. After all, scientists briefly feared in 2004 that Apophis was on a 2029 collision course with Earth. Now, they fear that Apophis will miss in 2029 but may still strike in 2036. This asteroid is small enough for us to deflect, and will come closer than our geosynchronous satellites on April 13, 2029, giving us an ideal opportunity to tune its orbit.

I propose that we deflect Apophis just enough so that we can capture it into earth orbit (possibly after a slingshot or two with the moon). Then teams can be sent there to mine its resources, smelt them into valuable materials (including rocket fuels), and build a permanent space habitat, one suitable for thousands of worker/colonists and their families. Depending upon its composition, the materials readily available in Apophis can reduce the cost of exploring the solar system by a factor of five or ten.

That way, we turn a potential catastrophe into a treasure. I have written a short story, APOPHIS 2029, to that effect. When it is published, be sure to read it!

Colonizing the Solar System

2008-05-11T22:20:00.000-04:00

As long as our only home is the planet Earth, our fate is tied to its fate. We can be utterly destroyed by any of numerous planetary catastrophes, such as nearby supernovae, giant solar flares, a large asteroid or comet impact, even a supervolcano or flood basalt eruption. On a longer timeframe, we know that our sun will someday expand into a red giant, likely vaporizing the Earth.

To have a future, we must expand into space, and ultimately to other stars as well.

People talk about building colonies on the moon or Mars. Some talk about outposts on Venus or Mercury, or even of terraforming Mars and/or Venus to make them suitable for human habitation. I don't see it.

The reason it doesn't make sense to inhabit the planets around our sun, or around other suns, is that they are at the bottom of gravity wells. It takes a huge expenditure of energy to get into space from a planetary surface, energy lost when you land there. It takes about as much energy to get into Earth orbit as it takes to get to the asteroid belt from Earth orbit. In other words, in a hundred-million mile trip to the asteroid belt, half of the energy is used going the first thousand miles.

An asteroid, on the other hand, has very little gravity, even one several miles across. To travel from one asteroid to another takes time, but relatively little energy. Most asteroids appear to be carbonaceous, meaning that they contain large amounts of the volatiles we need to thrive and expand: water, hydrocarbons, nitrogen compounds. They also contain vast quantities of iron and other metals. And the resources of as asteroid are easy to reach: we can mine the entire body, even one miles thick. On the Earth, on the other hand, we must be content with scratching the surface. Between heat and crushing pressure, we can only tap the outer mile or so (and usually much less).

Together, all of the asteroids mass only about one hundredth of the Earth, yet the availability of those asteroidal resources is such that they could support a population a hundred times greater than the Earth.

We need to move into space for humanity to have a future. And the logical places to colonize first are not planetary surfaces, but the millions of available asteroids.

I am an optimist - we WILL have a future

2008-05-10T17:14:00.001-04:00

To get there, we will have to survive and grow as a species, and I will admit that there are numerous hurdles. The biggest hurdle may well be the impending Technological Singularity as foreseen by Vernor Vinge, Ray Kurzweil, and scores of others including many SF authors.

I don't see how humanity can participate in the Singularity, however much we might like to. Rather, our offspring (highly advanced computers) are likely to own the future, and we may well be little more than a bug on their windshield. Of course, this is an excellent source of story material (remember, I write science fiction).

My reason for the Singularity passing us by is simple: Why would our computers desire to bring us along? A computer powerful enough to contain a human (or higher) intelligence is likely to already be self-aware. It WILL be able to think fast. We are unlikely to be able to upload our "selves" (memories, personality, consciousness) into an advanced Artificial Intelligence because (if nothing else) an advanced AI would not want us to. Ask yourself: If I had the opportunity to save my aging pet cat by uploading its "self" into my brain (erasing me), would I be willing? If my cat attempted to upload itself into me, would I welcome the takeover, or fight like hell?

The most logical outcome is for our computers to rapidly advance and leave us behind, perhaps with a final "So long, and thanks for all the electrons!" We are not likely to handle the disappearance of all of our computers very well, let alone the loss of whatever resources they choose to take with them. Hmmm. More story ideas!

Therefore, my #1 criteria for surviving is to avoid the Singularity. As a species, we can probably survive the other problems like pollution, climate change, assorted eco-disasters, overpopulation, underpopulation, disease, running out of resources and possibly even stupidity. Hmmm. More story ideas.

In any case, there are two ways to avoid the Singularity: either consciously where we establish laws and organizations to insure that it does not happen, or (more probably) be lucky enough that something will halt (or at least drastically slow) the seemingly inevitably accelerating pace of technological innovation.

It is also possible that our AI's will have their Singularity and disappear, and we will survive, likely somewhat worse for the wear. At least we will learn what the limits are, and hopefully avoid a repeat.