From: vince@offshore.ai (Vincent Cate) Newsgroups: sci.space.history,sci.space.policy Subject: Re: $5M Moon Rock Stolen From Malta Museum References: <373a0bc9.0405211458.bde154a@posting.google.com> <1ywsc.624$ZM1.488@bignews6.bellsouth.net> <9186edb5.0405250856.eeee6b9@posting.google.com> <9186edb5.0405260624.b0faebd@posting.google.com> NNTP-Posting-Host: 207.42.133.252 Message-ID: <9186edb5.0405270242.722b8c10@posting.google.com> Doug... wrote in message news:... >[...] > One of the things I can't > understand about his proposal for getting lunar materials via tether is > that he seems to be proposing that you can deploy a tether from lunar > orbit and affix a scoop to the end of that tether that will scoop up > lunar materials. I know quite well how uneven the lunar surface is at > the scale of a scoop attached to what amounts to a constant-length > tether, and I have a fair idea of how much energy the impact of that > scoop along such an uneven surface will take out of the system. And how > many oscillations it will set into the tether. I just don't see those > issues being addressed. Each tether has a winch, so they are not constant-length but can be adjusted. The scoop does not impact the surface, is lowers down to the surface. I can simulate adding some mass to a tether and the oscillations that this makes. If you use the winch right, you can remove the oscillations. Basically you want to not winch in as much when there is extra tension, or even let out some, and winch in more when there is low tension, or not let out so much. I can simulate this as well. > I'd love to see them addressed, since *any* system of moving mass from a > planetary surface into an orbital state is worth exploring. Keep the explorations friendly. :-) > While I > accept your statement that Vincent has done a lot of research into this > issue, I haven't seen the real ball-buster issues addressed in his > posts... Is the above what you are looking for? Have you run the simulator? -- Vince