Zubrin’s Pioneer Astronautics Selected for NASA Grant to Develop Radiator-free Engine

by Douglas Messier
Managing Editor

Bob Zubrin’s Pioneer Astronautics has been selected for a NASA Small Business Innovation Research (SBIR) award to develop a radiator-free engine (RFE) that could be used in nuclear electric and solar thermal electric propulsion systems.

“In the RFE, cold water propellant or hydrogen used as the heat rejection dump for a dynamic cycle heated by a nuclear reactor, enabling Carnot efficiencies as high as 0.79 for water or 0.99 for hydrogen,” the proposal’s technical abstract said. “Some of the propellant that is boiled or sublimated off is then sent to an electric propulsion system, which ejects it from the spacecraft at high velocities to produce thrust….