Word: heat
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Dates: during 1960-1969
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...insists that nuclear-powered rocketry is as important to U.S. security as the hydrogen bomb. Moreover, the theory behind Rover is disarmingly simple. In present U.S. and Russian space rockets, thrust is produced by the combustion of highly volatile chemical propellants. In Rover, a small nuclear reactor will generate heat that will expand hydrogen. This, in turn, will be directed out of the rear of the rockets to provide thrust. Because the reactor and the hydrogen take up relatively little room, scientists estimate that Rover will be able to haul triple the loads of conventional rockets, could be adapted...
...sign was the probe's temperature which climbed ominously higher as its elliptical orbit neared the sun. Nervously the scientists watched the faint telemetered reports of Mariner's thermometers. Just before the Venus-pass, Mariner reported a temperature dangerously close to the heat that would burst its batteries...
...constitute giant culture bowls-in both, water is being constantly recirculated and kept at certain temperatures that might happen to be suitable for the growth of the bacilli." Temperature seems to be a critical factor. In the laboratory, the bacilli grow poorly in a cool medium or at blood heat, do best at around 80°. That is in the temperature range of the exposed elbows and hands where they form abscesses-and of a heated pool or fish tank...
Radiation Cooling. Pratt & Whitney chose to work with these unpleasant fluids because building a nuclear engine for space requires a solution for one overriding problem: how to get rid of heat from the condenser. There is no air to cool it by convection; the only cooling comes from radiation, which increases sharply with temperature. If the working fluid were steam, an enormous condenser would be needed to radiate its low-grade heat. The lithium-potassium combination runs so hot that a fairly small condenser does...
Precision Collision. The standard method for synthesizing high-energy chemical fuels is to mix the ingredients and heat them. The heated molecules move faster, and a few of them move so fast that when they collide they stick to each other, creating new compounds with built-in energy. Instead of this haphazard system, says Vice President Milton Farber of Arizona's Rocket Power Inc., it is better to slam the molecules at each other with precisely enough energy to make them stick...