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Old February 17 2009, 05:54 PM   #43
John Picard
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Re: Should the USAF take over incompetent NASA?

Herbert wrote: View Post
Dusty Ayres wrote: View Post
John Picard wrote: View Post
Why do you say the propulsion system for a ship traveling to Mars has to be nuclear powered?
Because in most likelihood, it will have to be a nuclear engine that gets us to Mars. Only nuclear engines have enough thrust power to get a ship there, and also, NASA had already developed a nuclear engine for just such a task, the NERVA, but budget cuts and Nixonian indifference killed its development. That project has to be started again, and carried to full completion this time, regardless of whatever anti-nuclear protests will happen. It's the only engine system capable of getting people to Mars in back in a few weeks, and it's that simple.
I believe that in the current political climate, a NERVA (Nuclear Engine for Rocket Vehicle Application) engine is politically unacceptable. We're stuck with chemical propellants unless they can develop a Mach-Lorentz thruster, which is theoretical.

Another problem is that some in the scientific and space communities are opposed to manned spaceflight. They believe that sending fragile human beings to the Moon or Mars is much too costly and risky. It also takes funds away from robotic missions and they are skeptical how much science will be done during these missions.

Plus, like I said before NASA is doing a lousy job of selling "Project Constellation".
I believe Dusty is confused about using nuclear for space flight. It doesn't produce "thrust" in the same manner as a chemical rocket engine, but rather heat. We learned in high school physics class (1987) that a small amount of heat would be enough to "set things in motion" much like how an MMU uses small jets of air to propel a space walker. IIRC (without looking it up) the Pioneer spacecraft have a very tiny nuclear reactor that powers the entire craft with something in the neighborhood of 5 Watts and has been going since 1979(?).

One issue I see with a nuclear propeled vehicle is having a nuclear physicist on board to monitor and adjust the reactor as needed.

I agree with Herbert in that (IMHO) we're better off *JUST FOR NOW* in sending probes for the initial intel gathering and analysis.
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