-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Tuesday 02 October 2001 06:00 am, Ken Brown wrote: > Eugene Leitl wrote: > > Problem is high LEO launch costs. It would seem easier to build automated > > and teleoperate fabbing and (linear motor) launching facilities on Luna, > > and circularize orbit mostly by aerobraking.
High LEO launch costs are just down payments. It's literally true, energy-wise, that LEO is halfway to anywhere in the solar system. What's needed is a group of intelligent people and a "seed stock" of technology on the Moon. Teleoperation is great technology, but what's the point in these endeavours without a human component? Besides, teleoperation and AI and everything else breaks down, and the more complicated a thing is the easier it is to break it. Wheras humans... well, Scott Carpenter's description of an astronaut was roughly something like "A nonlinear computer with over 1 billion binary decision elements, weighing less than 200 pounds, and capable of being produced by unskilled labor". A large enough human presence is self-repairing, self-replicating, and self-controlling. The perfect world for rapid expansion. > And if you can put up a bloody huge enough launcher on the moon, (use > solar energy or nuclear - why not - it is one place in the system that > we don't care about pollution) then you can send material back all the > way to LEO by slingshot, and when it is captured by the facility at LEO, > if you do it right, you can get a "free" boost in orbit because of > greater orbital velocity of moon. Backwards. Higher orbit == lower velocity. As each component is added, you increase the mass of the station. You increase the energy of the total structure because the new component carries with it kinetic energy realized from the decrease in altitude, but rendevous and docking will probably waste all of that advantage in braking burns. Your chief advantage is that it takes much less energy to get from the Moon's surface to LEO than it does to get from the Earth's surface to LEO. > So the more you accrete onto your LEO station the higher it flies. Why > not make it the size of Wales? Why would you want to? If it's the size of Wales and solar maximum begins to drag it lower, how in the hell would you boost it again without throwing away all of Swansea as fuel? Easier and cheaper to use lunar material to build stations and equipment in High Earth Orbit, GEO, and at the LaGrange points. Especially at L4 and L5, you could build your station as large as you want (O'Neill designed them as large as 30 km, IIRC) and never worry about the mass because it won't ever go anywhere. > Hello Earth Station One. > > Well, 3 technically I suppose, Mir was One, the thing up there now is > Two. Can't really count Skylab. More like "11". Salyut 1 through 7, Skylab, Mir, and ISS or whatever the hell they're calling it this week. In terms of habitable volume, the Salyuts are the smallest, followed by Mir before expansion, then Skylab, then Mir after expansion, then ISS-as-designed. ISS-as-built is, I believe, somewhere between Mir and Skylab, although to be fair they aren't done yet. > There is a good fun fictional treatment of the lunar-driven space > station idea by Donald Kingsbury "The Moon Goddess and the Son". > Written before the Soviet Union fell. In the book they get done in by > home-made cruise missiles built out of private planes & off-the-shelf, > computers, autopilots, and GPS by Afghan refugees who studied aero > engineering in Europe and the US. I think it might be worth re-reading. > That and "Arslan" AKA "The Wind from Bukhara" by Madeleine (?) Engh. And for serious-but-light reading on the topic, look for "Colonies In Space" by Heppenheimer, "The High Frontier" by Dr. O'Neill, and more recently "Entering Space" by Zubrin. The first two are wildly optimistic, the last is actually rather pessimistic - I could argue with the numbers of all three, and reality is probably somewhere in the middle. The three also increase in technical detail and decrease is "fun" as you go down the list. - -- Matt Beland [EMAIL PROTECTED] http://www.rearviewmirror.org -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE7udh2BxcVTa6Gy5wRApBXAKD8DZgGMYM6lN4INfdfIb1hDD9oNQCePxQS 5JsNNwbde1TeI952dsXGDJw= =3taz -----END PGP SIGNATURE-----
