NASA revealed Tuesday that it will halt work on the lunar Gateway station and repurpose its nearly finished Power and Propulsion Element for a nuclear‑electric propulsion test flight. The module, built by Lanteris Space Systems in Palo Alto, will be fitted with a uranium‑fueled reactor and three 12‑kilowatt electric thrusters, forming the core of the upcoming SR-1 Freedom mission.

The shift follows a broader Trump‑era space policy that favors a Moon surface base over an orbiting outpost. Since the program’s 2019 launch, $4.5 billion has been spent on Gateway hardware, much of which now sits idle in factories worldwide. By converting the PPE, NASA hopes to demonstrate a 20‑kilowatt fission reactor—about twenty times the power of current deep‑space generators.

Administrator Jared Isaacman framed the effort as a proof‑of‑concept rather than a new flagship program, noting that the hardware and fuel are already largely paid for. With a launch window in December 2028, the agency must finish design by June and start assembly in early 2028, or miss the next Earth‑Mars alignment. Success would give the United States its first operational space nuclear reactor.