Problems in Cool-Down of Cryogenic Systems

Abstract

At the Los Alamos Scientific Laboratory the facilities and technology for handling large quantities of liquid hydrogen are being developed. This project is in support of the Rover program which is a joint endeavor of the Atomic Energy Commission and the National Aeronautics and Space Administration to develop nuclear- powered rocket engines. Since the power for propulsion is to be obtained from the nuclear reaction, the hydrogen, rather than undergoing combustion, is heated by the nuclear reactor and then exhausted through the nozzle. In this manner a specific impulse of about 750 seconds is obtained which can be compared with numbers like 300 seconds obtained when the propellant gas is the product of a chemical reaction. To date three successful tests have been made with reactors using hydrogen gas. Since the weight of containers per pound of propellant can be about 1000 times smaller for liquid storage than gas storage, it is advantageous that the hydrogen be transported as a liquid in a flyable reactor engine. To this end, facilities providing for the testing of reactors with liquid hydrogen are being constructed.

Work performed under the auspices of the U.S. Atomic Energy Commission.