Fission power back on NASA’s agenda

Michael Houts wants astronauts to ride a nuclear reactor to Mars. He is convinced that small amounts of uranium-235 — which has an energy density one million times greater than that of liquid fuels — could power rockets efficiently, using the heat of fission to accelerate small stores of lightweight hydrogen propellant. But although Houts, the nuclear-research manager at NASA’s Marshall Space Flight Center in Huntsville, Alabama, has an unwavering belief in the potential of space-based nuclear power and propulsion, the funding to develop that technology has been inconsistent. This year, he is leading a nuclear-propulsion project with a budget of US$3 million — minuscule in comparison with the $1.3 billion that NASA will spend on space-technology research and development in the 2012 fiscal year. “The funding at times has gone to zero,” says Houts. “You lose the teams and the momentum.”