NASA is advancing the development of a nuclear power system for its SR-1 Freedom spacecraft, which is scheduled to launch in late 2028 to demonstrate nuclear electric propulsion beyond Earth’s orbit.
The mission will mark the first time a fission-powered spacecraft travels beyond Earth orbit, paving the way for future deep-space exploration. NASA and its partners have agreed on key contract actions to accelerate development of the spacecraft’s nuclear power module and reduce technical risks.
Sierra Lobo Inc. will develop the closed Brayton cycle power conversion system, which converts heat generated by a nuclear reactor into electricity. The system will provide electrical power for SR-1 Freedom’s propulsion demonstration and will be integrated with a fission reactor being developed by the US Department of Energy’s Idaho National Laboratory.
The work will be carried out under a contract supporting spaceflight hardware development, testing and operations at NASA’s Glenn Research Center in Cleveland, Ohio.
NASA and the Department of Energy are incorporating safety measures throughout the spacecraft’s development, including interagency reviews, regulatory compliance and assessments of potential hazards. The reactor will remain inactive until the spacecraft has left Earth orbit.
SR-1 Freedom will also carry the SkyFall science mission, comprising three Mars helicopters developed from NASA’s Ingenuity design. The helicopters will collect scientific data, demonstrate exploration capabilities and identify potential water sources on Mars.
The mission is expected to advance nuclear-powered technologies for future deep-space missions, including systems that could support NASA’s planned Moon base during extended periods of darkness or in locations with limited sunlight.