Following a December 2025 executive order prioritizing \u201cAmerican space superiority,\u201d NASA is advancing nuclear propulsion under the leadership of Administrator Jared Isaacman.\u00a0<\/p>\n
The centerpiece of this new era is Space Reactor-1 (SR-1) Freedom. Slated for a December 2028 launch, it will be the first interplanetary spacecraft powered by a nuclear fission reactor.<\/p>\n
It aims to finally realize the long-held goal of nuclear-powered space travel by launching a nuclear electric propulsion rocket to Mars.\u00a0<\/p>\n
If successful, it would clear the path to the establishment of a permanent, nuclear-driven base at the Moon\u2019s south pole.<\/p>\n
Advancing nuclear goal <\/p>\n
Nuclear thermal propulsion has remained in a cycle of development, never reaching operational deployment.<\/p>\n
SR-1 Freedom aims to break that cycle by utilizing existing technology to meet a strict 2028 deadline.<\/p>\n
Despite 60 years of research and $20 billion spent on various failed or aborted programs, this mission seeks to succeed where its predecessors \u2014 such as the short-lived SNAP-10A \u2014 failed.\u00a0<\/p>\n
To ensure it hits the 2028 launch window, NASA is intentionally limiting the spacecraft\u2019s scope, pairing a single new nuclear reactor system with proven, existing technologies rather than attempting a total design overhaul.<\/p>\n
Isaacman characterizes the SR-1 Freedom as a \u201c70 percent solution,\u201d designed primarily to demonstrate the viability of nuclear propulsion rather than serve as a final, perfect model.\u00a0<\/p>\n
The spacecraft will use a 20-kWe reactor fueled by HALEU (High-Assay Low-Enriched Uranium) to power advanced electric thrusters.\u00a0<\/p>\n
It is expected to be activated within 48 hours of launch, beginning its year-long journey to Mars.\u00a0<\/p>\n
The system will use a closed Brayton cycle to convert heat into electricity, supported by heat pipes and a boron carbide radiation shield.\u00a0<\/p>\n
To manage thermal loads and propulsion, the craft will employ lightweight composite-titanium radiators and an advanced 48-kW electric propulsion system, which also doubles as the primary spacecraft bus for communications and power distribution.<\/p>\n
Skyfall mission<\/p>\n
Its primary mission? To act as a mother ship for Skyfall<\/a>, a triad of \u201cIngenuity-style\u201d helicopters.\u00a0<\/p>\n Equipped with ground-penetrating radar, the drone swarm will survey potential landing sites and identify ice deposits, providing the critical data needed to verify the terrain for upcoming crewed missions.<\/p>\n NASA has yet to determine the fate of SR-1 Freedom following the Skyfall mission.\u00a0<\/p>\n Officials are currently weighing whether the reactor-driven craft will perform a simple flyby or attempt to enter Mars<\/a> orbit once its primary cargo has been delivered.<\/p>\n \u201cThe team is still looking at exploring the opportunities. Once we drop off Skyfall what do we do with SR-1 Freedom?\u201d said<\/a> Steve Sinacore, NASA\u2019s fission surface power program executive.<\/p>\n NASA aims to move from hardware development in June 2026 to a December 2028 launch for SR-1 Freedom.\u00a0<\/p>\n This mission serves as a stepping stone for Lunar Reactor-1 in 2030, part of a broader shift toward mass-producing megawatt-class reactors for human Mars missions and commercial use.\u00a0<\/p>\n To sharpen this focus, the agency is pausing the orbital Gateway Program<\/a>, redirecting all resources toward establishing a permanent surface base at the lunar<\/a> south pole.<\/p>\n