Overview
- NASA unveiled SR-1 Freedom on Tuesday with a plan to launch by December 2028 as the first interplanetary spacecraft powered by a nuclear electric system.
- The spacecraft will use a 20‑plus‑kilowatt fission reactor fueled with high‑assay low‑enriched uranium that drives a closed Brayton turbine to generate electricity for xenon ion thrusters.
- NASA will repurpose the Lunar Gateway Power and Propulsion Element for the vehicle, with major design work starting by June, assembly readiness targeted for January 2028, and arrival at the launch site by October 2028.
- After activation within two days of liftoff, the reactor will power the cruise to Mars, where about a year into flight the craft will deploy three Ingenuity‑class helicopters to scout terrain and hunt subsurface water with ground‑penetrating radar.
- Leaders say the mission will set launch and regulatory precedent and build an industrial base, though key risks include securing HALEU fuel, completing safety reviews for launching a reactor, selecting a launch vehicle, and rebounding from DARPA’s 2025 cancellation of the DRACO nuclear program.