APPLICATIONS OF NUCLEAR PROPULSION TO MARS MISSIONS

Planning for a piloted mission to Mars entails consideration of a number of critical technologies-chief among these technologies is transportation. Transits to Mars are basically a double rendezvous problem: with Mars on the outbound leg while considering the alignments of Mars and Earth for the return to Earth. Nuclear propulsion, whether nuclear thermal propulsion (NEP) in which the reactor directly heats the propellant or nuclear electric propulsion (NEP) in which the reactor provides the electrical power for electromagnetically accelerating the propellant, offers several important benefits, including increased specific impulse, elimination of the oxider, and a decoupling of the energy source from the propellant. Studies have shown that the application of nuclear propulsion to Mars mission can shorten transit times for the same initial mass into low Earth orbit (IMLEO) or reduce the IMLEO for the same transit times. In addition the greater performance benefits of nuclear propulsion can provide the added margin for greater operational flexibility, including mission abort options and increased launch windows. During the 1950s and 1960s experimental and analytical studies showed the feasibility of nuclear propulsion. NASA, in cooperation with other agencies and organizations, is currently planning a technology development program for nuclear propulsion. The overall objective is to develop at least one NTP concept and one NEP concept for piloted and robotic (e.g. cargo) missions to Mars.