Sunday, August 26, 2012
"The main objective of project Rover/NERVA was to develop a flight rated engine with 75,000 pounds of thrust. The Rover portion of the program began in 1955 when the U.S. Atomic Energy Commission's Los Alamos Scientific Laboratory and the Air Force initially wanted the engine for missile applications. However, in 1958, the newly created NASA inherited the Air Force responsibilities, with an engine slated for use in advanced, long-term space missions. The NERVA portion did not originate until 1960 and the industrial team of Aerojet General Corporation and Westinghouse Electric had the responsibility to develop it. In 1960, NASA and the AEC created the Space Nuclear Propulsion Office to manage project Rover/NERVA. In the following decade, it oversaw a series of reactor tests: KIWI-A, KIWI-B, Phoebus, Pewee, and the Nuclear Furnace, all conducted by Los Alamos to prove concepts and test advanced ideas. Aerojet and Westinghouse tested their own series: NRX-A2 (NERVA Reactor Experiment), A3, EST (Engine System Test), A5, A6, and XE-Prime (Experimental Engine). All were tested at the Nuclear Rocket Development Station at the AEC's Nevada Test Site, in Jackass Flats, Nevada, about 100 miles west of Las Vegas. In the late 1960's and early 1970's, the Nixon Administration cut NASA and NERVA funding dramatically. The cutbacks were made in response to a lack of public interest in human spaceflight, the end of the space race after the Apollo Moon landing, and the growing use of low-cost unmanned, robotic space probes. Eventually NERVA lost its funding, and the project ended in 1973. Publication information: Information on Project Rover/NERVA provided by James Dewar."
A major problem here is creating a nozzle that can survive extremely high exhaust temperatures, ideally higher than with chemical propulsion.