NASA Advances SR-1 Freedom Nuclear Power System for Planned Mars Mission

NASA and its partners have agreed to contract actions to advance Space Reactor-1 (SR-1) Freedom’s development. The spacecraft is designed to demonstrate fission-powered systems beyond Earth orbit.

NASA plans to launch SR-1 Freedom toward Mars in late 2028 alongside three SkyFall helicopters.

What has been confirmed

NASA has confirmed that Sierra Lobo Inc. will provide the nuclear power module’s closed Brayton cycle power conversion system. It will convert reactor heat into electricity for the spacecraft and its electric propulsion demonstration. The Department of Energy’s Idaho National Laboratory is developing the fission reactor, which NASA plans to integrate with the conversion system. The work falls under NASA’s Space Flight Systems Development and Operations Contract III, awarded in 2024 for hardware design, development, testing, and operations at NASA Glenn Research Center. NASA plans to keep the reactor inactive until SR-1 Freedom leaves Earth orbit. NASA and the Department of Energy describe interagency safety reviews, NASA oversight, regulatory compliance, and safety-focused design processes as part of development.

Why it matters

SR-1 Freedom would test a power source intended to support spacecraft and electric propulsion beyond Earth orbit. NASA’s plan pairs that technology demonstration with a Mars-bound science mission, extending the mission’s purpose beyond power-system testing.

FlyMarshall context

A closed Brayton cycle system converts heat into electricity through a turbine-based process. For spacecraft, electric power can run onboard systems and support electric propulsion, which uses electrical energy to accelerate propellant. NASA’s mission plan combines this demonstration with SkyFall, three Mars helicopters based on the Ingenuity design, intended to collect scientific data, demonstrate exploration zones, and identify potential water sources.

What happens next

NASA plans to launch SR-1 Freedom in late 2028 and send it to Mars with the SkyFall mission. The agency has not provided a more specific launch date in the supplied facts.