Colonizing the Solar System

[Eclipse Now]

Originally Posted by CraigD

I hope I am – space elevators are beautiful technologies I’d love to live to see. I’m far from certain they will ever exist, though, as the engineering challenges they present are, to repeat myself truly daunting.

Consider this scenario: Advanced semi-autonomous unmanned vehicles, launched using 20th century technology, arrive after the usual multi-year trip in the Jovian moon/ring system. There, some drop electricity-generating tethers onto the surfaces of suitable minor moons, using the power to extract silicates and metals to construct large solar-power panels, more vehicles, and special-purpose particle accelerator/collector/refrigerators. Others collect hydrogen and oxygen from the atmospheres of Jupiter and Europa for use in conventional rocket motors.

This scenario blows my mind. However, for solar power wouldn't the moon be a closer place to manufacture it? If the solar power factories run on solar panels the intitial robots made, it could grow exponentially...

After decades of mining and assembly, immense solar-powered particle accelerators are boosted out of Jovian orbit into long, low-energy transfer orbits, ending in solar orbits closer than that of Mercury. There, they generate and expend hundreds of thousands of times the current artificial electrical output of Earth to, at very low efficiency, create, cool, and store at near absolute zero hundreds of kilograms of anti-hydrogen. This anti-hydrogen is used to fuel human passenger capable spacecraft capable of sustained multi-g acceleration and repeated Earth landings and launches.

Wow...

Once started, the industry-like process can expand, though not to unlimited size, to a great enough size that, after 50 to 75 years, transportation from Earth to other locations in the solar system is as available as 20th century air travel. Limiting acceleration to a human-comfortable 1 g, inner-planet destinations require 1-2 day flights, Jupiter 3-4 days, Neptune, the outermost great planet, 7-8, Pluto and other Kuiper objects 9+.

Now this is really interesting. Anyone got figures for the g's of STOPPING the other end after accelerating at 1g constantly? Or do these timeframes include turning around at the half way point and decelerating at 1g the rest of the trip.

Imagine the in-flight entertainment. "Ladies and gentlemen, half way approaches. Please secure all your belongings and strap yourself in for 5 minutes of Zero g, and if you are likely to feel nauseated, please use the refuse bag".

Here is a highly energy-inefficient technological system that completely opens the solar system to human colonization, yet requires no material unavailable in the 20th century. The great virtue of space elevators are their energy efficiency. In a technological system with abundant energy, elegant as they are, space-elevators might be as irrelevant as super-efficient light-emitting panels are in present day, modestly electric energy-rich, incandescent light-bulb-loving 1st world countries.

Point taken, although I'm still of the opinion that we're going to see an energy bottleneck for the next decade or so as we hit peak oil and try and just adapt to the end of cheap oil...

...but after this debacle, and our society has adapted to a renewable "electron economy", who knows WHAT our grandchildren will be able to achieve?

[CraigD]

Originally Posted by Eclipse Now

This scenario blows my mind.

Mine too. I wish I could claim to have invented it, but I actually got it from reading Stross’s 2005 novel Accelerando. I’m pretty sure Stross got the idea from someone who heard it from someone who heard it from ... its original inventor, whom I know not.

However, for solar power wouldn't the moon be a closer place to manufacture it? If the solar power factories run on solar panels the intitial robots made, it could grow exponentially...

The plan described here involves the construction of large Electrodynamic tethers, which depend on the presence of body with a lot of kinetic energy (the minor moon) relative to a magnetic field (Jupiter’s), not sunlight.

Regardless of what’s built to generate power where, however, the principle that using it to build more power-generating factories leads to exponentially growth, applies.

Wow...

Again, me too, and again, not my original idea. This one, I think, can be credited to Freeman Dyson (it’s one of many variations on partial Dyson spheres), and Robert Forward, who proposes near-sun orbiting solar-powered antimatter factories in such non-fiction works as Indistinguishable from Magic.

Now this is really interesting. Anyone got figures for the g's of STOPPING the other end after accelerating at 1g constantly? Or do these timeframes include turning around at the half way point and decelerating at 1g the rest of the trip.

They assume constant acceleration, forward half way, backward the rest of the way.

Imagine the in-flight entertainment. "Ladies and gentlemen, half way approaches. Please secure all your belongings and strap yourself in for 5 minutes of Zero g, and if you are likely to feel nauseated, please use the refuse bag".

Give these and more severe perils (eg: lose items becoming projectiles upon the resumption of acceleration), I imagine the turnaround would be done under the usual 1 g acceleration, requiring a slight adjustment in course before and/or after turnaround to compensate for the off-direction acceleration - just one of many factors impacting course planning.

Point taken, although I'm still of the opinion that we're going to see an energy bottleneck for the next decade or so as we hit peak oil and try and just adapt to the end of cheap oil...

...but after this debacle, and our society has adapted to a renewable "electron economy", who knows WHAT our grandchildren will be able to achieve?

I agree. The scenario I describe is very optimistic, and connected to no certain time frame.

The idea that it’s generations away, however, is no more well-supported than that it’s just around the corner. In our present day society, the great driver of extremely expensive projects is, I think, the prospect of either

• Survival, as during the cold war days of the early US and USSR space programs
• Making extremely great profits

Since, barring some very unlikely events, the idea that immediate human survival will depend on colonizing space is, I think, unlikely, we’re left with “making lots of money”. Though the orders-of-magnitude greater energy systems I describe could, at present, clearly make huge fortunes, I think more modest, short-term profit-making projects are needed, such as mining asteroids for rare metals, or the Moon for rare isotopes like Helium-3. I strongly suspect that, as RAH (and Robert L Forward, also) predicted, it will be greedy businesspeople who most further space colonization, rather than science and technology purists.

[Eclipse Now]

Surely one of the main drivers of the really HUGE exponential scenarios is the self-replicating "robots" described in the scenario's above? Do you think they have to be self-aware or approaching human level awareness of their surroundings (even given different senses etc), to be able to do their job? Or could they be partially directed? Or will good old fashioned human beings get out there in habitats to manufacture these energy sources?

Also, has anyone ever used actual anti-hydrogen or is that still just theoretical?

But I agree... in a scenario of unlimited power, who needs a slow, 'old fashioned' device like the space elevator (which could take a few days to ascend) when you can just get directly in the craft that is going to fly you all the way to your destination within the week?

I love this kind of techno-utopian dreaming, it's so refreshingly optimistic after considering the possibilities of collapse due to some peak oil Mad Max event. I used to worry that such an event might be inevitable... but I think that was more a reflection of my state of mind a few years ago than any reality. It is certainly possible that we'll nuke each other back to the stone age over the remaining oil, but hopefully that is only a very small possibility, and given recent trends in climate awareness hopefully peak oil will just propel us forward into a clean, green, energy secure and jobs-rich economy. Rather than 700 billion dollars a year leaving the USA for overseas oil, a renewable electron economy would put that 700 billion into fast rail (to offset ailing airlines), algae to jet fuel (to enable some airlines and some military fuels), BEV's for the domestic user (battery electric vehicles with SatNav's directing your trip to the nearest charging point or battery swap robot using WW2 bomber bay clips, see my post here for details of this starting in Israel), and of course ATTRACTIVE New Urbanism for the trendy, local, walking distance Urban environment that allows people to live "more European than European" in a car free zone in the first place! (A much more economical, efficient, trendy, and beautiful way to live than suburbia in my opinion. Instead of driving to work, imagine walking past your favourite bookstores and coffee shops).

So, the comforting thing in all this is that I imagine the first real human habitations in the asteroid belt or Mars or the Moon or even space habitats to be far more "New Urban" and "local economy" than anything we've known on earth.

Maybe social experimentation for those underground Martian habitats should be done in tightly planned New Urbanism townships here? Take 200 people and force them to live in military bunkers for a few years to simulate the first settlement, and then after a few years of building simulated 'materials' from the desert sand (or simulated regolith), they can then start to move out into the New Urban / space hybrid settlements they've built themselves?

Unless of course those 'robots' arrive just in the nick of time to build it all for them before they get there.

[Moontanman]

The Jovian system will be a harsh environment for even robots much less humans. The radiation is quite intense, and complex computers are vulnerable, humans are out of the question. Saturn might present a better environment for both humans and robots.

[Eclipse Now]

Is it a different kind of radiation? Isn't there intense solar radiation on the surface of Mars and the Moon, and yet people are talking about bases there?

Yeah, I say we start at the moon and launch stuff from there. I hear there is water on the moon after all? Silicon for Solar PV, water, a few volatiles for other components.... everything we need for a space program AND a much lower gravity well to get out of.

Water Found on the Moon | Wired Science

[Moontanman]

Yes it is a different type of radiation, Jupiter has huge intense band of "vann allen" type radiation caused by the intense magnetic field of Jupiter, electron bombardment in the Jovian system is harsh enough to kill a human in a few minutes. The Earth traps solar radiation too and has Van Allen belts but they are orders of magnitude less than those at Jupiter.

Jupiter Radiation Belts Harsher Than Expected

Wapedia - Wiki: Magnetosphere of Jupiter.

[CraigD]

Originally Posted by Eclipse Now

Surely one of the main drivers of the really HUGE exponential scenarios is the self-replicating "robots" described in the scenario's above? Do you think they have to be self-aware or approaching human level awareness of their surroundings (even given different senses etc), to be able to do their job? Or could they be partially directed? Or will good old fashioned human beings get out there in habitats to manufacture these energy sources?

My guess – and a low-confidence guess it is – is that the factory robots I describe in “in a 1,000,000 times more energy rich civilization” would be not very dissimilar to present day unmanned spacecraft, capable of performing many tasks fairly autonomously, but, far from having human-like self-awareness, having essentially no planning capability. To paraphrase an old joke, when it comes to manufacturing, creativity has fewer practical applications than you might expect.

As for being self-replication machines in the sense long described in literature, I think much of the expected difficulty, and to some extent, mystique, of making such systems comes from the assumption that such machines need

1. Be of a single design
2. Be completely autonomous

When these requirements are removed, it seems to me that our mundane world has been full of self-replicating machines for the better part of a century or more, since machine-power began being used in nearly every stage of manufacturing processes, from mining to final assembly. Take practically any manufacturing processes, and imagine simply remote-controlling the human parts of it, and you have, in principle, imagined a processes that, once vacuum and radiation-proofed, can be done remotely in space.

I’m being a bit sneaky in saying “simply remote-control the human parts”, as remote-control robots that actually can do the things we take for granted a human can, such as pick up and precisely position a wide variety of objects, twist a screwdriver, turn a wrench, or clean up a mess, are barely in their infancy. However, I see no hard barriers to eventually achieving what I imagine, and no requirement for true artificial intelligence.

Originally Posted by Eclipse Now

Also, has anyone ever used actual anti-hydrogen or is that still just theoretical?

Cold neutral antihydrogen has been successfully manufactured and stored for short periods in significant quantities since about 2002, with significant improvements in technology through about 2005, and continuing. Several good histories of this are available online, such as CERN’s “antimatter factory” website.

Although its feasibility for energy storage has been confirmed, at present antihydrogen is much too expensive to produce and in demand for experiments to use as an engineering fuel. The present-day cost and efficiency of manufacturing antihydrogen (and, occasionally, antihelium) is staggering, leading researchers in the field to note that it’s cost is on the order of $50,000,000,000,000/gram, and all of the antimatter manufactured to date, at the cost of $100 of millions, is about enough to power a single light bulb for a few minutes – were it still around.

It’s also proven somewhat harder than anticipated to store antimatter. Although “trap” storage devices that can store neutrally charged antimatter such as antihydrogen with very low power requirements (ordinary disposable batteries are commonly used, because they’re cheap and reliable) have been designed and built, methods or cooling antimatter sufficiently that it can be held in them have proven successful, maximum storage times are on the order of an hour. Charged antiparticles have been successfully stored with on the order of 100 days, but even very cold, can’t be stored as densely as neutral antimatter

Originally Posted by Moontanman

The Jovian system will be a harsh environment for even robots much less humans. The radiation is quite intense, and complex computers are vulnerable, humans are out of the question.

I agree, though like the Earth’s radiation belts, Jupiter’s are fairly well-defined, and un-leaky, so as long as humans and vulnerable machines stay out of them – the wiki article you link, Moontan, mentions NASA’s HOPE study concluding that Callisto, the outermost of Jupiter’s large moons, is within the human safe zone at about 1,880,000 km out, while Ganymede at about 1,070,000 km, isn’t. My guess is that any humans living near Jupiter – and, assuming the need for human control of much of the operation, the benefits of having people as close to the worker robots might outweigh the risks and costs – wouldn’t be on the surface of a large moon, but either a very small one or none at all.

As demonstrated by the success the long-duration Jupiter orbiters Galileo, despite having been built in anticipation of about 1/3 the radiation encountered, the engineering problems presented are not insurmountable.

The strong, extended magnetic field responsible for Jupiter’s radiation belts are the reason why it’s attractive for the “energy mining” I describe, because they provide a means of converting the kinetic energy of bodies orbiting Jupiter into useful energy - in essence, with the addition of relatively small lengths of conductors, Jupiter and its ring/moon system can be used as a giant, already-spinning electric generator. Using it this way will eventually de-orbit whatever body you extract energy from, but not before you’ve gotten all the energy needed for the next step of the larger project.

Originally Posted by Eclipse Now

Is it a different kind of radiation? Isn't there intense solar radiation on the surface of Mars and the Moon, and yet people are talking about bases there?

As Moontanman noted, the radiation levels on the surface of lunar or Martian surface are many times less than those in Jupiter’s radiation belts.

As for it being a different kind of radiation, I’d say it’s a difference in quantity, not quality. In both cases, and also with the Earth’s Van Allen belts, the major source of radiation are high-speed protons emitted by the Sun (there’re electrons, too, in different belts, but with about the same speed and much less mass, they’re much lower energy, so not as significant a threat). Jupiter, or any planet with a significant magnetic field, captures these protons, concentrating them in higher densities than the usual solar wind, resulting in belts with more dangerous radiation than in space or on moons and planets. Also, since belts segregate particle by charge, bodies in them can accumulate charge, which can literally lead to sparks flying (also mentioned in Wapedia - Wiki: Magnetosphere of Jupiter).

Originally Posted by Eclipse Now

Yeah, I say we start at the moon and launch stuff from there. I hear there is water on the moon after all? Silicon for Solar PV, water, a few volatiles for other components.... everything we need for a space program AND a much lower gravity well to get out of.

As the greatest accumulation of material near Earth easier to lift into space than from Earth, the Moon is a major resource in space-engineering projects on the scale we’re discussing.

However, it’s important to note that, despite it being easier to lift material from the Moon’s surface than from Earth’s, it’s far from easy. Lunar escape velocity is about 2400 m/s, vs. Earth’s 11200, so ignoring complications, it takes about 5% () as much energy to lift the same mass from the Moon as from Earth. This is still a lot of energy, especially until you can build an efficient device like an electric mass-thrower to do it, and until something like that’s accomplished, also requires a lot of resources. Taking the ca. 1970s Apollo LEMs as examples, about half of the mass of their ascent stages were fuel/propellant – which on the volatile-poor Moon, must almost certainly be imported from Earth at the usual great cost.

I think it’s important to take look at space engineering from a high-level, strategic perspective. Just as 19th century industrialists were wise to build factories connected by rivers and railroads to coal mines, large-scale space engineers need to build their factories near large sources of easily usable energy. The main idea of my “in a 1,000,000 times more energy rich civilization” speculation is that the kinetic energy of the moon systems of giant planets is such a source, and a possible step toward using the much greater but less easy-to-get-a-lot-of-power-from source of the Sun.

[Eclipse Now]

Except that the ultimate goal of anti-hydrogen seems to be mainly sci-fi today.

What was the Kim Stanley Robinson propulsion system using materials gathered from the gas giants themselves? Are we saying that harvesting the gas from Jupiter is now out because the equipment required to do that would be "nuked" by radiation?

[Theory5]

A space elevator is cool, but have you ever read any books by Ben Bova? (excellent fiction writer, he writes stories about exploring the solar system, a few notable books are mecury, venus, mars, jupiter, and The Sam Gunn Omnibus and all the stories overlap to create one universe.)
A space elevator could be built on the equator, and as was mentioned in a previous post (To tired to go back and find it) wouldnt the space elvator collapse?
The Answer is possibly, but the way to build a space elevator is to create thin strands of a really strong wire, maybe buckyball wire, and build a space station far enough in space. The trick will be to pull thread down from the sky, while also bringing it up in rockets or something, and effectivly create a rope where the space station is pulling up on the rope and the earth is pulling down. And as like in one of Ben Bova's books I think 'terrorism' might be a threat (without the nanobots :-) )
A question I have though is, dont the van allen belts produce enough radiation to be harmful?

[Eclipse Now]

I'm not sure about Earth's Van Allen belts affecting the space elevator, unless there were people required to stay in those Belts. How high are the belts? Surely not high enough to affect the station at the end of the 36k km long elevator?

But in the KSR books the Martian space elevator came down, and because it was built quite thick as it came into Mars to crash, with the base of it being pulled around by rotation of Mars, it gradually accumulated speed like a giant whip. The majority of it ended up crashing down around the equator a couple times the speed of sound, with the detonative force of a series of small nukes! (taking out everything within a km or so of the impact line). That was a great moment in storytelling, but also a rather horrible idea when considering the potential impact on earth. What would something like that do for ocean tsunami's around Bangladesh, India, Indonesia, the Carribean, America's and Northern Australia? Yeeeeouch!

Make a cool movie effect though. Move over Bruce Willis in Armageddon, the elevator is coming down! Any movie title suggestions?