From the late 1950s to the early 1970s a major US program successfully developed the capability to conduct space exploration using the advanced technology of nuclear rocket propulsion.
October 1, 2021
From the late 1950s to the early 1970s a major US program successfully developed the capability to conduct space exploration using the advanced technology of nuclear rocket propulsion. The program had two primary elements: Rover and NERVA (Nuclear Engine for Rocket Vehicle Application). Part of the NASA space program, the former provided the basic reactor design, fuel materials development, and reactor testing capability with pioneering work performed by Los Alamos National Laboratory (LANL) and its contractors. NERVA meanwhile was focused on engine development by the industrial team of Aerojet and Westinghouse, building on and extending the Los Alamos efforts for flight system development. The challenge of this part of the program was designing nuclear engines that could survive the shock and vibration of a space launch.
Together, these programs demonstrated the space-practical operation capabilities of nuclear thermal rockets, which would be launched from Earth orbit, and established a technology base that includes proven nuclear thermal rocket capabilities, including:
- Over double the specific impulse of chemical propulsion systems (and nearly triple that of chemical rockets with the same exhaust gas temperature).
- Thrust capabilities in the range 10,000–250,000 pounds of thrust.
- Practical thrust-to-weight ratios for future NASA space exploration missions, both manned payloads to Mars and unmanned payloads to the outer planets. The objective of a mission to Mars was announced out in 1969, and scheduled for 1981.
This article summarizes the lessons learned in the development of this technology, illustrating that surprises are certain to be encountered when under-taking such advanced programs. Because of the speed with which the program was conducted, many—if not most—of the experimental results were reported only in informal progress reports. The program began under the military during the Cold War, resulting in classification of this material until program termination. At that time, data were declassified wholesale, much of which were subsequently destroyed.
