3 ms·

A new documentary highlights the visionary behind space settlement

2 points by obi1kenobi 6y ago

PaulHoule 6y ago
If anyone killed the O'Neill colonies it was Eric Drexler who figured out that you could build the solar power satellites by blowing large plastic films and vapor depositing layers of metals and semiconductors on them. The mass of the satellites is so much less than that of the colonies that you could have launched them from Earth if you, say, modified the Saturn V first stage so it worked like the "Super Heavy" and returned for reuse and then had a family of "Space Shuttles" that bolted on top of it. Instead we got something Ralph Nader would have warned you about so Drexler gave up on systems engineering of a space blanket factory in space for the systems engineering of "nanosystems" which would let him dream that someday he'd plant a seed and grow an SSTO in his back yard. Today the use case is the 10^11 kg or so sunshade at the Earth-Sun L1 point but people estimate that a comfortable deep space habitat is 10^8 kg per head or so, so you can't afford to have a crew of 10,000 people working on it, but you might afford to have 50. The moon is close in terms of kilometers but far away in terms of energy. The big advantage is that sending people there is feasible as is remote controlling robots. Many asteroids are gassy inside with the gas retained by a 'skin' and inside (assuming you trap the gas safely) you will find abiogenic "coal" that is close enough to coal to design a coal gas plant that can build up anything organic via C1 chemistry. That consumes oxygen produced by the 'metal' line which gives iron, aluminum, other elements to produce quality steel and aluminum alloy. If you find nitrogen on the asteroid you have a very good case for a biological economy, e.g. millions of human bodies, cattle, food, etc. That is much more fundamental to civilization than the metals and stones that the moon is rich in.

3 ms·

A new documentary highlights the visionary behind space settlement

2 points by obi1kenobi 6y ago

PaulHoule 6y ago
If anyone killed the O'Neill colonies it was Eric Drexler who figured out that you could build the solar power satellites by blowing large plastic films and vapor depositing layers of metals and semiconductors on them. The mass of the satellites is so much less than that of the colonies that you could have launched them from Earth if you, say, modified the Saturn V first stage so it worked like the "Super Heavy" and returned for reuse and then had a family of "Space Shuttles" that bolted on top of it. Instead we got something Ralph Nader would have warned you about so Drexler gave up on systems engineering of a space blanket factory in space for the systems engineering of "nanosystems" which would let him dream that someday he'd plant a seed and grow an SSTO in his back yard. Today the use case is the 10^11 kg or so sunshade at the Earth-Sun L1 point but people estimate that a comfortable deep space habitat is 10^8 kg per head or so, so you can't afford to have a crew of 10,000 people working on it, but you might afford to have 50. The moon is close in terms of kilometers but far away in terms of energy. The big advantage is that sending people there is feasible as is remote controlling robots. Many asteroids are gassy inside with the gas retained by a 'skin' and inside (assuming you trap the gas safely) you will find abiogenic "coal" that is close enough to coal to design a coal gas plant that can build up anything organic via C1 chemistry. That consumes oxygen produced by the 'metal' line which gives iron, aluminum, other elements to produce quality steel and aluminum alloy. If you find nitrogen on the asteroid you have a very good case for a biological economy, e.g. millions of human bodies, cattle, food, etc. That is much more fundamental to civilization than the metals and stones that the moon is rich in.