Space Reactor‑1 Freedom advances nuclear power module

NASA announced that Space Reactor‑1 Freedom will be the first spacecraft to use fission power outside Earth’s orbit. The mission, revealed at the agency’s Ignition event, will carry a science package called SkyFall to Mars. The spacecraft will demonstrate nuclear electric propulsion for deep‑space travel.

Nuclear power module design

The key element is a nuclear power module located on a boom. It contains a reactor that generates heat by fission and a closed‑Brayton cycle system that turns that heat into electricity. Sierra Lobo Inc. supplies the power‑conversion unit, while the Department of Energy’s Idaho National Laboratory designs the reactor. The module is being built under a contract awarded in 2024 and incorporates rigorous safety reviews and oversight.

The reactor will remain shut down while the spacecraft stays in Earth orbit. Space Reactor‑1 Freedom is slated for a late‑2028 launch and will deliver the SkyFall science mission to Mars, which includes three helicopters evolved from the Ingenuity design. The mission will test deep‑space propulsion and pave the way for future fission‑powered systems that could support a lunar base during dark periods or in places where solar power is insufficient.