In what’s likely to be one of the last space policy initiatives of his administration, President Donald Trump has issued a directive that lays out a roadmap for nuclear power applications beyond Earth.
Space Policy Directive 6, released on December 16th, calls on NASA and other federal agencies to advance the development of in-space nuclear propulsion systems as well as a nuclear fission power system on the Moon.
“Space nuclear power and propulsion is a fundamentally enabling technology for American deep space missions to Mars and beyond,” Scott Pace, the executive secretary of the National Space Council, said in a White House news release. “The United States intends to remain the leader among spacefaring nations, applying nuclear power technology safely, securely and sustainably in space.”
Space-based nuclear power isn’t exactly a new idea: NASA and the Atomic Energy Commission considered thermal nuclear propulsion – a concept that would have involved heating up propellants with a nuclear reactor – way back in the 1970s as part of Project NERVA.
A different kind of nuclear power, which converts the heat from radioactive decay to electricity, has been used with hardware ranging from Apollo lunar surface experiments to the Curiosity rover on Mars. (NASA’s Perseverance rover, which is due to land on Mars in February, also has a radioisotope power system.)
NASA once considered putting a nuclear electric propulsion system on a spacecraft known as the Jupiter Icy Moons Orbiter, but that mission was canceled in 2005. Now there’s renewed interest in missions that require more power than can be generated by solar arrays – and that’s reviving interest in nuclear power for space applications.
At a National Space Council meeting that was held last year in Washington, D.C., NASA Administrator Jim Bridenstine said nuclear propulsion systems would be “absolutely a game-changer” for space travel. The safety guidelines laid out at that meeting set the stage for the new directive.
Reacting to the release of Space Policy Directive 6, Bridenstine hailed nuclear power as an enabling technology for NASA’s Artemis program, which aims to establish a base at the Moon’s south pole during the 2020s.
“NASA strongly supports the White House’s continued leadership on the agency’s Artemis program, which includes landing the first woman and next man on the Moon in 2024,” Bridenstine said in a news release. “At the Moon we will prepare for new science and human missions deeper into the solar system. SPD-6 bolsters the agency’s efforts to develop affordable, safe and reliable nuclear systems, including technology capable of continuously powering operations on other worlds and propelling future human missions to Mars.”
NASA is working with the Department of Energy and commercial partners to design a nuclear plant capable of generating 10 kilowatts of electrical power on the Moon. The demonstration power plant, which would make use of technology developed for NASA’s Kilopower project, could become a reality in the late 2020s.
It’s not clear how the change in the White House would affect plans for nuclear power in space – but for what it’s worth, President-elect Joe Biden sees terrestrial nuclear power as one of the avenues for easing the climate crisis.