Message posted by Tom on May 02, 2002 at 7:42:53 PST:
I had to learn a bit about NERVA while following up on certain avenues of exploration. It turns out there’s a great deal of documentation out there, particularly in technical journals such as the Journal of Spacecraft and Rockets. AvWeek also had some items. The NERVA engines numbered over 20, and were essentially sophisticated steam engines. The heart of the engine was a cylindrical graphite reactor, sort of like an oversized trash can. The reactor merely provided a source of heat. Hydrogen was fed into the engine, hit the hot core, greatly expanded, and shot out the ass end at high pressure and speed. An unfortunate aspect of the earlier NERVA reactors was that bits of radioactive graphite from the reactor also blew out the ass. Not a polite thing. The difficulty was that the hotter the thing ran, the more efficient it became. As a result, they ran the reactor near 3,500 F, pretty darn close to the point that would do in graphite. When it wasn’t spewing its guts out, the hydrogen that was emitted was only slightly radioactive. It was a very simple and elegant design. The early engines were tested vertically, firing up. The later ones were also tested vertically, but firing down into a special diverting chamber under a partial vacuum, which would simulate nozzle conditions at high altitude. Most of the original NERVA facilities remain out on Jackass Flats in reasonable condition. In particular, the buildings and hot cells where the reactors were loaded with uranium are supposed to have been mothballed in a high level of preservation. Had the program not been axed due to politics and radiation hysteria, we probably would have already been on Mars by now. They were really neat engines.
In Reply to: Project "NERVA" posted by John on May 01, 2002 at 11:06:35 PST:
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