White House Releases Space Nuclear Initiative

The White House Office of Science and Technology Policy issued the National Initiative for American Space Nuclear Power today. Attempts to develop space nuclear power and propulsion date back to the 1960s and the Trump Administration is trying once more to invigorate those efforts as part of the Moon-to-Mars goals and for national security uses.

OSTP Director Michael Kratsios rolled out the Initiative in concert with the Space Foundation’s annual Space Symposium in Colorado Springs. He and NASA Administrator Jared Isaacman appeared on stage separately and then together as they cheered the successful completion of the Artemis II mission and looked ahead to the future.

The Initiative spells out interagency relationships for the development of space nuclear power and propulsion among NASA, the Department of Defense, and the Department of Energy. President Trump’s December 18, 2025 Executive Order on Ensuring American Space Superiority gave OSTP 60 days to issue guidance on “enabling near-term utilization of space nuclear power by deploying nuclear reactors on the Moon and in orbit, including a lunar surface reactor ready for launch by 2030.”

Then-Acting NASA Administrator Sean Duffy announced the goal of putting a fission reactor on the surface of the Moon by 2030 last year.  At the Ignition event last month, Isaacman went further with a plan to first launch a small interplanetary fission reactor by 2028 named Space Reactor-1 Freedom, or SR-1 Freedom. SR-1 is envisioned as a nuclear electric propulsion system that will drop off three small Ingenuity-class helicopters on Mars — “Skyfall” — before heading further into the solar system. A 20 kilowatt electric (20 kWe) fission reactor at one end will power thrusters at the other end using the repurposed Power and Propulsion Element from the lunar Gateway space station that Isaacman canceled.

SR-1 wasn’t the main focus of OSTP’s document today, however.  It looks more broadly at the future use of low-, mid-, and high-power space nuclear systems by NASA and DOD. The Department of Energy is a critical player in any nuclear endeavor since it manages the U.S. nuclear stockpile and oversees laboratories that conduct nuclear research.

For NASA, Kratsios said “nuclear power in space will give us the sustained electricity, heating and propulsion essential to a permanent, robotic and eventually human presence on the Moon, on Mars, and beyond.” Isaacman added “it’s not that you can necessarily say with certainty today that we are going to require so much power on the Moon that we’re going to need lots of fission power capabilities” but “it’s the perfect proving ground to master the skills you’ll need for what comes next” particularly manufacturing propellant on Mars from local resources.

Isaacman pointed out that the United States has spent over $20 billion on dozens of space nuclear power and propulsion initiatives over the decades and only one has flown — SNAP-10A in 1965. The 1960s also saw early efforts to develop nuclear thermal propulsion in the NERVA program, a joint effort between NASA and the Atomic Energy Commission, DOE’s predecessor. NERVA was canceled when enthusiasm for space exploration waned at the end of the Apollo era.

More recently, Trump’s first-term Space Policy Directive-6 set out a national strategy for space nuclear power and propulsion; the National Academies of Sciences, Engineering and Medicine issued a report on space nuclear power and propulsion for human exploration of Mars in 2021; and NASA and the Defense Advanced Research Projects Agency (DARPA) announced a joint effort to develop a space nuclear thermal propulsion demonstration, DRACO, by 2027. The Trump Administration terminated DRACO last year.

For NASA, OSTP’s memo primarily is about development of fission surface power (FSP) and Nuclear Electric Power (NEP). While it doesn’t preclude nuclear thermal propulsion (NTP), it directs the agency to focus on “common NEP/NTP components for initial use on the potential NEP demonstrator.”

NASA has 30 days to initiate a program to develop a “mid-power space reactor with a lunar fission surface (FSP) variant ready for launch by 2030, and an option for a space variant for a nuclear electric propulsion (NEP) demonstration.”

For DOD, OSTP directs that “pending availability of funding,” it should “pursue deployment of a mission-enabling mid-power in-space reactor by 2031.” However, in the first year, it must “contribute” any available space nuclear funding to NASA’s effort.  DOD has 90 days to brief White House offices on the analysis and assessment of the best use of a 2031 mission.

Note: The Trump Administration refers to DOD as the Department of War, but the name can only officially be changed by Congress, which has not done so yet.