Title: ASSESSMENT OF THE ADVANTAGES AND FEASIBILITY OF A NUCLEAR ROCKET FOR A MANNED MARS MISSION

The feasibility of rebuilding and testing a nuclear thermal rocket (NTR) for the Mars mission has been investigated. Calculations indicate that an NTR would substantially reduce the earth-orbit assembled mass compared to L02/LH2 systems. The mass savings were 36% and 65% for the cases of total aerobraking and of total propulsive braking respectively. Consequently, the cost savings for a single mission of using an NTR, if aerobraking is feasible, are probably insufficient to warrant the NTR development. If multiple missions are planned or if propulsive braking is desired at Mars and/or at Earth, then the savings of up to $7 billion will easily pay for the NTR development. Estimates of the cost of rebuilding a NTR were based on the previous NERVA program’s budget plus additional costs to develop a flight ready engine. The total cost to build the engine would be between $45 Billion. The concept of developing a full-power test stand at Johnston Atoll in the Pacific appears very feasible. The added expense of building facilities on the island should be less than $1.4 billion. The concept of using a Nuclear-Thermal Rocket (NTR) for a manned mission to 1,2 mars has been considered for over 30 years. The obvious advantage of producing about 2 times the Isp of chemical rockets allows 1) a lower total mass to be assembled for a given payload mass, 2) the possibility of much faster,