Sorry to put the final nail in the coffin of the S5, but I have it on good account that the last existing 3rd stage engine, for which there are no existing plans or other prototypes, was obliterated in a high speed impact.
Seems an LSD-addicted grad student/intern working at the Space Center here in Houston stole it, rigged it up on a 1964 Mercury pick-up truck (oddly, the last one of them too), and rigged it for testing in Big Bend Park, on the Rio Grande. Our brave, albeit idiotic and ergo doomed Texan Icarus got behind the wheel and fired it up. The entire ungainly assembly immediately took to the air, achieved Mach 0.88, crossed the Big River and slammed into a mountain side some 55 miles SSE of Ciudad Juarez. The Mexican government, despite an outraged (though still covert) CIA and White House, swept the crash site clean of all debris and disavowed any knowledge of the incident. They have since reclaimed the technology, R. E.'ed it into three sizes and are secretly testing their own heavy launch vehicle at this writing. The presence of numerous Russian rocket scientists and Cuban automotive executives in the night clubs in Nuevo Laredo confirms my worst suspicion. Mexico is about to eclipse us all, and take the first real step into commercial exploitation of the space business. Though it saddens me that this item has been succinctly put to rest, perhaps we can all now refocus upon our favorite shiny marble, Europa. Jack W. Reeve [EMAIL PROTECTED] -----Original Message----- From: Michael Turner [mailto:[EMAIL PROTECTED] Sent: Tuesday 09 September 2003 03:59 To: [EMAIL PROTECTED] Subject: micro-nano-pico engines (was Re: Prometheus propulsion) As long as we're still off-topic, please note an admirable catalogue of proposed micro-/nano-/pico-thruster technologies, found in the following paper: A Systems Study on How to Dispose of Fleets of Small Satellites Jason M. Andringa, Daniel E. Hastings http://ssl.mit.edu/publications/theses/SM-2001-AndringaJason.pdf Ion engines and Hall thrusters come up, as well as an idea so obscure as to be a Googlewhack: the Spindt Microvolcano (no really!). The only page I find, searching Google on "spindt microvolcano", is the above PDF file. (Well, by the time you read this, my Icepick submission might be indexed, so it's sort of self-cancelling to write this.) What a great conversation-stopper -- when you're talking with some skeptic heaping scorn on blue-sky research into propulsion, you can loftily drop the little meme-grenade: "Well, perhaps, but what about Spindt Microvolcanoes?" Also amusing: digital propulsion -- small combustion/detonation charges triggered by random access of their igniters in an on-chip array. Not mentioned above, but available at a decent engineering library near you "Shock waves at microscales" M. Brouillette in _Shock Waves: An International Journal on Shock Waves, Detonations and Explosions_, V. 13, #1, July 2003 in which it's pointed out that scaling down internal combustion engines and gas turbines breaks their principles of operation ("heat is being lost faster than it is being produced (in addition to proportionally more import frictional effects as well)" explaining why such devices fabricated at microscale to date haven't worked. However, the author goes on to say, detonations may well work, and the experimental integrated shock tubes proposed, modeled, and constructed at a larger scale so far hold out the promise of a pico pulse detonation engine (picoPDE). Unfortunately, it is virtually certain that lower exit velocities will result, even if higher pressures can be produced, and diffusion effects may further blunt any conjectured advantage. The field of nanotech propulsion is wide open, but the possibilities are not unlimited. Nanotech is a mixed bag. Christopher England: > There are many details in the design of > EP engines that need to be addressed including keeping the spacecraft > electrically neutral. I was under the impression that this is pretty much a solved problem with ion drives. No? > Materials limitations. Yes, my comments are "current technology > based" as you suggest. I also am hoping for a breakthrough heat > rejection technology. Such a breakthrough would have enormous benefit > for spacecraft and for space travel. Unfortunately, there is no Moore's Law for certain problems. You can't break basic thermodynamic laws. If current systems are somewhere near their theoretical limits, no amount of microscaling or materials improvements will get you past those limits. Great fun, by the way, to have space urban legend discussion on this list (the supposed "lost arts" of Saturn V). As a friend of mine once said, after relating a particularly tasty factoid, "No, wait a minute -- that one can't be true. I've heard it too many times now." -michael turner [EMAIL PROTECTED] ----- Original Message ----- From: "Christopher England" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, September 09, 2003 3:06 AM Subject: Re: Prometheus propulsion > > Robert, Here are my answers > > > Chris, has anyone done an analysis to determine whether one could > > produce a high-thrust ion engine "complex" using nanotech? .... > > My guess would be that there would be significant gains in thrust > > due to multiple micro-engines but that this might be limited due to > > things like voltage and insulator constraints. > > 1. Nanotech for ion propulsion. Ion propulsion gains its theoretical > advantage by the high velocity of ions leaving the engine. This engine > works by reaction so the mass x velocity imparts momentum and velocity > to the spacecraft efficiently. If nano-devices could do this better, > I'm for it. Ion propulsion needs propellant. Nanoscale devices would > have to be fed propellant, or, perhaps, consume themselvess. I would > guess that storage of propellant is best done centrally, an advantage > for larger engines. > > One can get very high electrical fields around nanoscale structures, so > maybe there is a way to use nanotechnology to reduce the electrical > needs. This approach has been proposed previously, but I haven't > studied the possible benefits. There are many details in the design of > EP engines that need to be addressed including keeping the spacecraft > electrically neutral. > > > I also suspect that your comments regarding radiator limitations > > and the need for refractory metals may be somewhat "current > > technology" based. > > 2. Materials limitations. Yes, my comments are "current technology > based" as you suggest. I also am hoping for a breakthrough heat > rejection technology. Such a breakthrough would have enormous benefit > for spacecraft and for space travel. And would find beaucoup > applications on Earth. > > Chris > == > You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] > Project information and list (un)subscribe info: http://klx.com/europa/ > > == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/ == You are subscribed to the Europa Icepick mailing list: [EMAIL PROTECTED] Project information and list (un)subscribe info: http://klx.com/europa/
