Re: space shuttle obsolete
On Jul 31, 2005, at 8:40 PM, Dan Minette wrote: While the power/weight ratio is wonderful, the efficiency is worse than a conventional engine. ... If things go well, they would probably have a good battery substitute for military use in about 4-5 years. Which, I think, is the point -- it doesn't have to be as efficient as a conventional engine, it only has to be more efficient than a battery. Which reminds me of the old joke, you don't have to be faster than the bear, just faster than your companions. Dave "Bomb squad: If I'm running, try to keep up" Land ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: space shuttle obsolete
- Original Message - From: "Gautam Mukunda" <[EMAIL PROTECTED]> To: "Killer Bs Discussion" 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 timeor 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
Re: space shuttle obsolete
--- Robert Seeberger <[EMAIL PROTECTED]> wrote: > > - Original Message - > From: "Gautam Mukunda" <[EMAIL PROTECTED]> > To: "Killer Bs Discussion" > Sent: Saturday, July 30, 2005 10:49 PM > Subject: Re: space shuttle obsolete > > > >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. > > > > Any info would be appreciated. That is a pretty geewhizbang story! If true, its neat.. but sounds awfully like the talk I heard presented by the guy who was gung-ho about Tesla turbines.. -kerri, finally decompressed from World Series of Poker- __ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: space shuttle obsolete
- Original Message - From: "Gautam Mukunda" <[EMAIL PROTECTED]> To: "Killer Bs Discussion" Sent: Saturday, July 30, 2005 10:49 PM Subject: Re: space shuttle obsolete >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. > Any info would be appreciated. That is a pretty geewhizbang story! xponent Uranium Tri-Carbide Maru rob ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: space shuttle obsolete
--- Doug Pensinger <[EMAIL PROTECTED]> wrote: > Gautam wrote: > > > 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. > > Fascinating stuff, Gautam, but why _wouldn't they > choose to do it? > > Doug Well, among other reasons, because I think it might be illegal, as such a rocket would also qualify as an ICBM :-) In all seriousness, I don't actually know. He said they've actually gone ahead and designed all the hard parts, and actually built some of them, so he didn't feel it was much of a challenge. OTOH, I'm not sure what _use_ putting 10 kgs into LEO would be right now. 10 kgs isn't that much. If someone were to right him a check for the amount, he seemed very confident he could do it. My guess is that scaling it up to launch heavier payloads is a bit more of a challenge, but, judging by his talk (I am not, after all, a specialist in nanotech) eminently doable. Gautam Mukunda [EMAIL PROTECTED] "Freedom is not free" http://www.mukunda.blogspot.com Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: space shuttle obsolete
Gautam wrote: 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. Fascinating stuff, Gautam, but why _wouldn't they choose to do it? -- Doug ___ http://www.mccmedia.com/mailman/listinfo/brin-l
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. It was astonishing - one of the most interesting hours of my life, really. I've never seen a presentation anything like it - and it was most impressive not because it was all "blue sky" projects but because everything he was talking about was either _already working_ or very close to being so. 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. Gautam Mukunda [EMAIL PROTECTED] "Freedom is not free" http://www.mukunda.blogspot.com Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs ___ http://www.mccmedia.com/mailman/listinfo/brin-l
Re: space shuttle obsolete
- Original Message - From: "Jon Mann" <[EMAIL PROTECTED]> To: Sent: Saturday, July 30, 2005 1:40 AM Subject: space shuttle obsolete > Use tried and true disposable solid fuel boosters to launch satellites, > robotic missions, scientific experiments, etc. And when necessary, > human astronauts to work on the space station, make repairs on the > Hubble, etc. Rather than using an antiquated shuttle system it would > by more practical to develop nuclear powered smaller vehicles that > could be launched like the Mercury, Gemini and Apollo Capsules, but > with better propulsion and maneuvering technology. 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. >It could remain > docked to the space station, providing additional living space, and > available for interorbital missions, such as repairing the Hubble and > eventually returning to the moon. It is impractical to launch heavy > shuttles out of the gravity well and then return them to earth, > subjecting them to re-entry damage and endangering the lives of our > hero astronauts. No matter how you slice it, space travel is still a risky business. I would hope that the advances in technology of the last 30 years would allow us to build a safer means of transport. Especially since manned space fight is still in the PR stage, so very little in terms of scientific advances can be attributed to it. Dan M. ___ http://www.mccmedia.com/mailman/listinfo/brin-l
RE: space shuttle obsolete
-Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jon Mann Sent: Saturday, July 30, 2005 4:10 AM To: brin-l@mccmedia.com Subject: space shuttle obsolete Ever since the Space Shuttle Challenger exploded on takeoff I realized NASA technology is neither safe nor cost effective, but a multi billion dollar business. I believe that the Russian approach to orbital launches is cheaper and far less dangerous. It appears the Chinese will also be relying on rocket launches rather than expensive and inefficient orbital vehicles. Here is my idea that I have proposed to friends who have far more knowledge and expertise than a layman such as myself. Use tried and true disposable solid fuel boosters to launch satellites, robotic missions, scientific experiments, etc. And when necessary, human astronauts to work on the space station, make repairs on the Hubble, etc. Rather than using an antiquated shuttle system it would by more practical to develop nuclear powered smaller vehicles that could be launched like the Mercury, Gemini and Apollo Capsules, but with better propulsion and maneuvering technology. It could remain docked to the space station, providing additional living space, and available for interorbital missions, such as repairing the Hubble and eventually returning to the moon. It is impractical to launch heavy shuttles out of the gravity well and then return them to earth, subjecting them to re-entry damage and endangering the lives of our hero astronauts. Continue to use them in orbit and return the astronauts the old fashioned way. The logistics should not be difficult. ___ http://www.mccmedia.com/mailman/listinfo/brin-l I'll say this First before I go farther, I really don't want to be a nay sayer to your idea as I have similar views about the current and future manned space exploration outlook. However, there are several things that I would like to highlight from your post as some food for thought about it. "I believe that the Russian approach to orbital launches is cheaper and far less dangerous. It appears the Chinese will also be relying on rocket launches rather than expensive and inefficient orbital vehicles." Though I do agree that "now" this approach is a safer bet for crew survivability, there were quite a few launch failures with loss of payload and crew, the US shuttle program can only see 2 massive failures to date Challenger and Columbia. Before I make my next point off of this I will make some admissions, I will not argue that the Shuttle is tres expensive. However at the time it was built is was the cutting edge in technology, and as was said in a previous post if you were to ask a shuttle engineer if they thought the shuttle would be flying in '05 they would laugh, the thing simply was not meant to be in operation for 30+ yrs. (yes I know they all didn't come out in '75 but the design has been around since the) The reason why the vehicles themselves are cheaper is because they are toss away, im sure someone with more knowledge will tell me that they salvage much of the electronics from one Soyuz for one under construction replacing as needed to reduce cost, but I don't know that for sure. The shuttle was designed to be a multi task vehicle, which it still is, what is needed is a modular system with a return to earth capability something again modular but in the sence that the payload module can be launch automated and return to earth automated after dropping off its payload, and have a reuse of say 15+/- flights. I would want the option that the crew module can launch and return on its own, so if you have to do a crew change on the ISS you don't have to launch an entire vehicle. In the same breathe I would want it to have the option of launching with the payload module. " Rather than using an antiquated shuttle system it would by more practical to develop nuclear powered smaller vehicles that could be launched like the Mercury, Gemini and Apollo Capsules, but with better propulsion and maneuvering technology." Ok here I go sounding like a crazy scared old nuclear watch dog.. I think that giving a larger power source to manned and unmanned missions is a great idea, and very necessary as it takes away power limits for scientific payloads on DS missions. However the more you launch them and return them the higher the chance of a catastrophic failure and we have a nuclear could falling over the world. even as you have put it they would stay docked to the ISS there has to be away for the crew to return home, so they have to have reentry capability, and poking a nuke on a one hop capsule to me just isn't cost effective. Granted as I said above you can salvage from each cap. And drop cost but I'm still wary about having a crew return vehicle that has a nuke on board. Before you say well we can have it removable in orbit and it can be connected to the ISS for additio
