NASA’s SR‑1 Freedom Nuclear Reactor Advances Toward 2028 Mars Mission

LATEST MATERIAL CHANGE

What changed?

NASA’s Space Reactor‑1 Freedom, the first spacecraft to use fission power beyond Earth orbit, is progressing on its nuclear power module. The module combines a reactor that generates heat and a closed Brayton cycle system from Sierra Lobo Inc. to convert that heat into electricity for propulsion. The reactor, designed by DOE’s Idaho National Laboratory, will remain off until the vehicle exits Earth orbit. Contract actions signed with partners aim to reduce technical risk and keep the 2028 launch on schedule. Freedom will deliver the SkyFall payload—a trio of Mars helicopters—to study the planet and test deep‑space exploration concepts, laying groundwork for future lunar bases that rely on nuclear power when solar energy is insufficient.

Why it matters

It marks the first use of nuclear electric propulsion in deep space, enabling sustained power for missions where solar energy falls short.