----- Original Message ----- From: "Gautam Mukunda" <[EMAIL PROTECTED]> To: "Killer Bs Discussion" <brin-l@mccmedia.com> Sent: Saturday, July 30, 2005 10:49 PM Subject: Re: space shuttle obsolete
> --- Dan Minette <[EMAIL PROTECTED]> wrote: > > In what sense would these be nuclear powered? > > Nuclear propulsion is > > practical for long, slow accelerations, not lifting > > off a massive body like > > the earth. Relatively little progress has been made > > in that area because > > the physics is straightforward, and the chemistry > > basically just chemical > > engineering. I think material science is probably > > the area where the > > advances would be most useful. The next most > > important advance would be > > rugged electronics. In my own limited field, we > > subject electronics to far > > greater stresses than anything one would expect > > going to space. > > Let me toss in a different technology - nanotech. The > single most interesting thing I attended in my year at > MIT was a talk by an aeronautical engineering > professor here on the aerospace implications of > nanotech - in particular, the nanotech developments > _already working in his lab_. One of the things that > he showed us were massive increases in the efficiency > of jet and rocket engines. He actually handed out a > working jet engine about the size of my thumb. The > engine for the F-22 - probably the most advanced > "normal" jet engine in the world has (IIRC - it's been > several months now) an 8:1 power to weight ratio, > which is pretty good. This little thing, a first > generation engine using nanotech, has a 50:1 power to > weight ratio. There is a long article at: http://www.technologyreview.com/articles/04/11/freedman1104.asp about this guy. There are a few caviats involved. While the power/weight ratio is wonderful, the efficiency is worse than a conventional engine. So, the nanotech involved is making an engine turbine a bit smaller than a dime, letting it spin 1 million RPMs and keep it working for a long time. According to this article, the jet cannot work continuously, the turbine is unstable, etc. The develops think it will take 2-3 more years to iron out these wrinkles. If things go well, they would probably have a good battery substitute for military use in about 4-5 years. > He thought, IIRC, that he and his grad students could, if > they chose, build a rocket that could put 10 kgs in > LEO for about $50,000. It was just mindblowing - I > wish I had a tape of the presentation so I could show > it to people. Given the fact that he is getting millions in contracts from the military, it's hard to believe that they would not have an interest in this. A 50k contract would not buy much of his time....or that much in hardware for that matter. It would have to be a modest grad student project, with only a bit of advice from the major prof. Sounds like a neat engineering PhD topic; I'd guess that the successful student would have little trouble getting a job for a big defense contractor. So, I'd be a bit more skeptical of that claim. Dan M. _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
