User talk:BlaiseGassend

Hi there. Saw you getting involved in Wiki space writing (I am a relative newbie myself), looked at some of your MIT rocket group pages and space elevator things, and wanted to welcome you. Congratulations on graduation, hope you enjoy it out in the "real world". I was a post doc with Walter Lewin & Jeff Hoffmann in 1976-1979, and worked with Gerry O'Neill & Henry Kolm there on the 1977 MIT Mass Driver, so I have happy memories of earlier days. I especially enjoyed your simulations of cable breaks, which are about as I expected, but much more detailed and substantial of course.

Have you thought much about the lunar case, over Earth/Moon L1? Pearson proposed this in 1979, as you probably know, and I am confident it is stable when anchored to the lunar surface, even though L1 is unstable for a free particle. I am excited about that, as it requires no magic materials, and could reduce the Earth(LEO)/Moon round trip total mission velocity from ~12 km/sec to only ~3 km/sec, assuming aerobraking to get into LEO. Then we could get LOX from oxides on the Moon, and only have to ship up LH2 from Earth to have LH2/LOX in LEO, for whatever purposes. It also has no problem avoiding Earth-orbiting assets currently in place. Finding significant amounts of C on the Moon would make it easier of course, as we could more easily make most of it from lunar materials, after carrying up just a seed fiber to L1. There is also the possibility of making solar cells out of lunar Si, hoisting them to L1, assembling into SSPS's, and then using an ion drive to move them down to GSO.

Cheers, Bill Wwheaton (talk) 21:17, 9 February 2008 (UTC)

Cool, saw your edit to Space elevator. You're probably busy doing important stuff, but if you ever have any spare time you might want to check out Launch loops; they actually seem to be possible right now (no weirdo materials needed), they seem to offer cheaper, more frequent launches, and the capital costs are lower. They're also, I think, much less well explored; there's only a couple of papers on them AFAIK. It's the 'other space elevator'.- (User) WolfKeeper (Talk) 22:07, 9 February 2008 (UTC)