Ramblings on the Future of Humanity

Your math is correct. A minor point: microwave re...

2012-02-12T06:04:33.194-05:00

Your math is correct.

A minor point: microwave rectennas can achieve much higher conversion efficiencies than 60%; even 90%.

More importantly, however, is that the 230 w/m2 is a design point that allows people (and wildlife) to thrive even when in the beam. If we don't care about cooking them, we can use much higher energy densities.

Most importantly, that energy is available 24x7, while ground-based solar power doesn't work at night, when it's cloudy, or in early morning or late afternoon when the sun angle is too low, and the fraction of time of high sun angles varies by season. On average, ground solar is available perhaps 8 hours per day (more in dry deserts where you don't need it, less in high-latitude cloudy areas like the mid-west and north-eastern states where you need it most).

A last point: solar radiance in space is 1367 w/m2, while on the ground is only about 1000 w/m2 even when the sun is shining directly overhead.

It appears to me that this would result in 230 w/m...

2012-02-11T18:55:18.318-05:00

It appears to me that this would result in 230 w/m2 at the earth. Given a 60% aperture efficiency this would be ~140 w/m2. Solar can be much higher, even if it has lower availability.

Can you comment on whether the SPS is competitive?

A link to the Wikipedia S-IVB article: http://en.w...

2012-02-05T14:58:26.568-05:00

A link to the Wikipedia S-IVB article:
http://en.wikipedia.org/wiki/S-IVB

Whoa. A little more reading reveals that there are...

2012-02-05T14:56:54.743-05:00

Whoa. A little more reading reveals that there are several third stages of the Apollo mission vehicles that were put into solar orbit. (Maybe there are Russian Boosters also?) The linked article at Wikipedia says there are 5 S-IVBs in heliocentric orbits making 6 total, possibly spaced at two months apart in Earth's year around the sun. Their empty weight was 20,000 lbs and their physical make up is also documented and might be targets which might not need Earth return.
Hmmm, a nice mission might be to get one, toss it back at earth then go to a second one and capture it for return. Or maybe even, after the second one, gather Snoopy and return both the S-IVB and Snoopy to prove handling of a broken asteroid.

That was from Apollo 10 (or X), sorry.

2012-02-04T20:47:51.007-05:00

That was from Apollo 10 (or X), sorry.

Hey, I just became aware that the crew section of ...

2012-02-04T20:45:56.927-05:00

Hey, I just became aware that the crew section of the Apollo Lunar Module, Snoopy, after separating from its launching base (which crahed into the moon) was separated from the main capsule, Charlie Brown, and the remaining booster fuel was fired off to set into a heliocentric orbit. Meaning it should be an easy go to practice approach and retrieve target for any asteroid program. With this object we know its material make-up so there'd be no surprises there. It weighs around ten tons. If it were captured and placed into Earth orbit, a shuttle could have returned it from orbit. But some other means of that could be devised (A special re-entry shell?) We keep missing the fly-bys, let's bring back a piece of history. The only remaining Lunar Module should be worth something (all th eothers were moon crashed after rendezvous with the main crew capsules)

I forgot to ask ... where did you get your oxygen ...

2011-12-28T22:56:45.401-05:00

I forgot to ask ... where did you get your oxygen per day value ? I would be interested in reading more about that, if you could post a web site or some such would be great ;)

The NASA papers I have read suggest closer to 3 liters of water per person not including hygiene or cooking. (oops 2.6Kilos is almost 3 liters) Could the "burning" of the inedible plant stuffs be achieved with a solar furnace, since the sun is a ready source of free energy? we also shouldn't forget about the human need for over packaging, all that can be recycled as well for various compounds.

A couple of issues, the habitat's breathing en...

2011-12-28T22:46:53.103-05:00

A couple of issues, the habitat's breathing environment will need an inert gas to lower fire risk, Nitrogen is a good one as it is used elsewhere and is going to infiltrate the system anyway.
One of the NASA web pages covers the caloric needs for one astronaut and they use 2000 to 3000 calories for moderate to heavy workload in space in zero G.
As for farm field overhead height I would suggest walking room so you dont have to use robotic harvesting machines... which if they break down in the middle of the field have to be crawled to to repair.
As for ammonia, if you provide for tilapia and chickens and algae early on you provide 3 enjoyable food stuffs and one distasteful one. while all 3 work together to feed each other and provide the nutrients and chemicals needed for other resources.
Launching the needed stuffs into orbit with your idea is a Novel way to do it. Another option might be to use the weather balloon type idea and float the object to the stratosphere and then launch from there. This has the advantage of allowing for less propellant as the required burn time is now much less as well the needed delta V for achieving orbit.
The N-P-K needs could also be partially met by growing plantains in the habitat since plantains provide all the needed nutrients for human consumption and the waste materials can be converted into the required fertilizers in one process or another. So you now have 4 good food items and 1 bad one.. add in the goats and you also increase the manufacture of propellants via methane or you increase your CO2 content. If you ship dry ice up when payloads have room you allow for a way to increase the CO2 for the gardening zone. If you hold off on the green plants during initial build-up and store excess CO2 as dry ice you can start with a surplus that might be sufficient to maintain the high level of CO2 needed for plant growth until the population maxes out.
As these are older posts we now know the moon does have all the materials and ingredients needed to allow for an alternate location of material supply including water and the various metals.
If one of the plants concerns in rooting then g rowing willow will allow for a natural root starter and can be continuously recycled back into the needed nutrients as well as be used for a natural pharmaceutical. The same goes for plants like clover which can also be fed to rabbits; again increasing our good foods and limiting the less visually pleasing foods.
The Ph levels can be controlled to some extent by rotating to crops that need higher acidity levels, asparagus, thus reducing the Ph. If we grow Dwarf pines we can increase acidity and provide a form of vitamin C with Pine tea and Charcoal for purification. The charcoal can then be used to purify water and remove odours from the air and be used to resupply the CO2 needed for plant growth.

"What crops should we grow? In general,...

2011-12-23T20:26:22.047-05:00
"What crops should we grow? In general, dwarf varieties of grains [...] We’ll have bread and pasta from wheat"

You haven't read Wheat Belly, have you?

"And the resources of as asteroid are e...

2011-12-22T06:09:32.718-05:00
"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)."

That's called "overburden". It's composed of valuable minerals. Once that overburden is mined, the ore that was underneath is no longer hot and under pressure. You can continue this mining process all the way to the center of the earth, without having to worry about heat and pressure, because as you mine you're removing the overburden that was the cause of the heat and pressure.

Another lost opportunity: 2005 YU55. Six years of ...

2011-11-09T14:50:29.715-05:00
Another lost opportunity: 2005 YU55. Six years of knowledge that this object would be travesing within the range of the Moon's orbit and what did we get from the scientific money earners? "Slowly, get the cameras ready. Don't make any sudden moves, you might scare it?

Yes, this is a call to reproduce, targeted to ever...

2011-11-04T12:14:50.442-04:00
Yes, this is a call to reproduce, targeted to everyone who's DNA might make a positive impact on the future of humanity. This includes (in my opinion) healthy, intelligent, and optimistic people. The kind of people whose descendants can find solutions to the world's problems and limitations - and not just those depending upon the "traditional" population control measures of famine, starvation, disease, and war.

Ms. "I Can't Believe It", you might reconsider your last statement, since history and arithmetic are the foundations of my post: those who reproduce the most effectively will own the future, overwhelming those who don't. Simple arithmetic demonstrates that even small improvements in reproductive success dominate in the long run. Ask your Neanderthal neighbors.

My key point is simply that if WE don't reproduce faster then THEM, we will soon be extinct (whoever WE and THEM are). Your decision is simply whether you wish to be part of the WE or part of the THEM. If YOU choose to not have children, thus saving the world's resources for future generations, that's great. But recognize that YOUR children won't be a part of that future; your genes won't survive. I'm okay with that.

What an incredibly irresponsible hymn to reproduct...

2011-11-04T02:34:42.835-04:00
What an incredibly irresponsible hymn to reproduction this blog entry is, given that we just achieved 7 billion people. Everyone already feels entitled to soil our nest with the sprawling, consuming, breeding millions. Such a go-forth-and-multiply statement at a time such as this is tantamount to infanticide. You condemn future generations to famine and war. Do you have no conception of history and arithmetic?

2011-11-04T02:31:31.241-04:00
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Two objects have come to be observed that may bear...

2011-09-22T07:30:57.658-04:00
Two objects have come to be observed that may bear relevance to this effort. One is in the forward Trojan position (L4). The other isan Earth orbit companion that travels mostly with the Earth in a corkscrew orbit!. They are an order of magnitude different in size The L4 one, 2010_TK7, is quesstimated to be 300 meters in size. The more massive one is the corkscrew, 3753_Cruithne, estimated to be 3 kilometers in diameter and 1,3 x10^14kg! Quite massive and riding along on our highway with us and constantly changing lanes without a directional light.
I think Cruithne is too big to use for a capture target itself. Where its greatest resource may lie is as a gravity well which is near by! Not the Moon but still it gives us the potential to add more dVs to any equational re-orbiting attempt. It is also so massive that it may itself have object of a size we could manage to harvest in its Lagrange points! objects on the size of 2010 TK7. We should seriously spend a tremendous effort to map the vicinity of Cruithne to find harvest targets.
Now as to 2010 TK7. Hey, its already in a Lagrange point 60 degrees ahead of us (That equates to one sixth of a year or 60 days ahead, 300 days behind but a total of 365 days to and from) it could be used as a practice destination for a Mars mission! Steven's desire for a habitat could begin there. Anything built there would only take 60 days to drop back to Earth. If we have not one (Earth) nor two (Earth & Moon) but three rescue stations for any Mars mission, it makes it that much more safe to accomplish. We might start a Mars mission there, swing back at Cruithne, then the Earth and then the Moon to sling with loads of dVs to boost to Mars! Study of 2010 TK7 is a must too.Since it is in a type of stable null gravity field at the L4, it may, even with its weak gravity well, be the central object in a mini-system. We could harvest its orbitals for resources there and here!
Jus tsome encouraging outlooks I thought I'd pass along. (sorry I didn't spell check if there were any)

I think i'm slightly better than average on lo...

2011-09-16T19:21:55.256-04:00
I think i'm slightly better than average on looks and intelligence however reproduction is not an option for me. my genes go with me 6 feet under hahaha. let other genes play the game of "survive and procreate"

Slingshots! Remember that the Apollo 13 mission wa...

2011-09-16T05:54:58.308-04:00
Slingshots! Remember that the Apollo 13 mission was changed from a Lunar orbit insertion to a slingshot aimed back at the Earth? That was the most beautiful Slingshot trajectory calculated and done on a die or else true deadline.

Also we can place emphasis on the safety of solar ...

2011-09-09T17:25:03.796-04:00
Also we can place emphasis on the safety of solar power satellites. All other energy currently used has intrinsic safety and environmental concerns. The misrepresented dangers of Nuclear meltdown, deep-sea oil drilling, Fracking, and mining (etc.).

Remember that any object that threatens us would m...

2011-09-05T00:37:08.610-04:00
Remember that any object that threatens us would most likely be on the same order of mass magnitude as the one we captured. So, a great gravitational effect could occur. If a planet sized object came at us, say goodbye. But, it would probably be on the order of an Appophis sized asteroid which could be dealt with by any of the objects you've identified. Cosmic Billiards anyone?

Interesting idea, Michael. My first thought was ne...

2011-09-02T05:51:51.895-04:00
Interesting idea, Michael. My first thought was negative - any mass small enough that we can readily sling it around is too small to have much effect. But then again, a small effect might be all we'd need. It sure beats not having a mass to sling around! And if parked near an unstable Lagrange point (L1 or L2 come to mind), we might be able to use a few slingshots to give us some free momentum and launch it out to where it's needed.

Yes, a very interesting idea.

Another reason for having a controlled mass at our...

2011-09-02T02:24:58.409-04:00
Another reason for having a controlled mass at our disposal would be to also assist if needed in deflecting any other objects that might come our way. Stephen, I think you should updadte your list of purposes for having a captured asteroid around to include this defensive aspect of it. Whether its mass is used to divert by gravitation or actually smash into a rogue object would depend on the situation. But I'd rather have one at the disposal of future generations than leave them dependent on just a nuclear arsenal for the task.

Thank you, MikeL. We've always known that the...

2011-08-31T06:01:33.949-04:00
Thank you, MikeL.

We've always known that the reality of an Apophis capture mission would be different than my plan as described. It will certainly have a different size and mass (hopefully not too much larger), and its actual path will certainly be different from the current "nominal" path, but again not by too much.

I wanted to describe a mission that is feasible given what we know today, as a starting point for what could be an extremely important actual mission in the future.

Bootstrapping humanity's move into space is the most important step we can take into the future, and it's great that we could do it while (1) reducing global warming, (2) preventing an asteroid from slamming into the Earth, and (3) making a profit.

What's Obama waiting for?

Hi Stephen, I was at your ISDC talk and enjoyed i...

2011-08-31T05:11:22.393-04:00
Hi Stephen,

I was at your ISDC talk and enjoyed it greatly. It's great to see you're still working on the process. It seems to me from what I've read that some of the uncertainties with the 2029 encounter may yet change the values of the delta v required to bring apophis into orbit. Hopefully we'll know more in 2013.

There's an elegance to the way this mission could fulfil Obama's "go to an asteroid" mission while having this second productive result. Good luck making it happen!

QuantumG, you are right, 30+ months in zero G is a...

2011-08-28T08:10:02.929-04:00
QuantumG, you are right, 30+ months in zero G is a potentially serious problem. At the same time, the mission is complex enough I don't see how to handle it robotically.

Remote mining & manufacturing missions are not only possible, they will likely dominate in the the long run. But getting started, bootstrapping the process, is a different issue. The cost of sending a workforce in the thousands to a distant asteroid may be prohibitive, until we can build mining & manufacturing habitats in Earth orbit, populate them, and then migrate the entire structure out to where the asteroid resources are. But I don't see that happening until we run out of low hanging fruit (asteroids that may be captured into Earth orbits). It is also more likely that we'll send robotic missions to return bags of ore (with minimal processing) to earth orbit, at least until the space population grows significantly enough to provide a self-sustaining market.

Loved the presentation Stephen. I watched the sec...

2011-08-28T05:25:36.010-04:00
Loved the presentation Stephen. I watched the second half today on the NSS youtube channel.

I notice your tug ship doesn't have any artificial gravity, and you don't mention creating any until they get back to Earth orbit. Perhaps by the late 2020s there will be some medical mitigation techniques for zero-g health issues but currently this is a show stopper for a 30+ month mission.

How feasible would you consider it to do mining/colony development on an asteroid in solar orbit, with just the solar power satellites and spaceships returned as products to Earth orbit? Such a "distant colony" strategy could be favorable for the larger asteroids.