During the past five decades, the US Navy has successfully operated a number of nuclear thermal propulsion systems with the characteristics similar to those required for long duration, nuclear powered, space missions. If nuclear reactor\u27s are to be utilized for space propulsion, they will embody many characteristics such, as size, mobility, environmental security, crew safety, and long-duration independent-operation capabilities which have already been demonstrated by their Navy counterparts. The authors present a brief overview of both Project ROVER, NASA\u27s most extensive nuclear propulsion program to date, which resulted in a total firing tine of 1,020 minutes at power levels above 1.0 megawatt, This is contrasted with Navy operational nuclear reactor experience for significantly • longer periods of time at high average power levels, Technical issues central to the operation of Navy nuclear reactors which arc directly applicable to nuclear powered , manned, space missions are explored. The Navy \u27 s nearly perfect safety record, enviable environmental record, as well as significant design, and operational experience achieved during approximately 3 , 800 reactor-years of operation make its experience and, corporate opinion both authoritative and convincing in nuclear matters while providing a data base of extreme value which should not be ignored in the development of future space nuclear systems
