NASA’s SR-1 Freedom Advances with Progress on Nuclear Power Module

NASA and its partners have agreed to key contract actions to advance the Space Reactor-1 Freedom mission, humanity's first fission-powered spacecraft to operate beyond Earth's orbit. Slated to launch in late 2028, the spacecraft will demonstrate nuclear electric propulsion in deep space while carrying a science payload known as SkyFall.

Sierra Lobo Inc. will build the nuclear power module’s closed Brayton cycle power conversion system, which turns reactor heat into electricity. This hardware development occurs under an existing contract supporting NASA’s Glenn Research Center.

Meanwhile, the Department of Energy’s Idaho National Laboratory is designing and developing the fission reactor itself. The spacecraft relies on nuclear fission—splitting atoms to generate heat—to power its systems and electric propulsion.

Program director Steve Sinacore stated that the recent contract actions reduce technical risk and maintain momentum for the 2028 target. NASA and the DOE apply strict safety standards, ensuring the reactor remains inactive until the craft safely leaves Earth orbit. Upon arrival, the SkyFall mission will deploy three Mars helicopters based on the Ingenuity design to gather scientific data and locate potential water sources. The technology is also expected to support future systems, including power generation for NASA's Moon Base during prolonged periods of