NASA Advances SR-1 Freedom Mission to 2028 Launch
The mission aims to test fission-powered propulsion for deep space exploration and future lunar base energy requirements.
Updated on Oct. 20, 2026 in Nuclear
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NASA has officially begun contract actions for the SR-1 Freedom mission, the agency's first spacecraft powered by a fission reactor designed for deep space. The mission, managed through the Space Flight Systems Development and Operations Contract III, is scheduled to launch in late 2028.
Why it matters
This mission tests nuclear electric propulsion, a critical technology intended to enable long-term space exploration and provide consistent power for lunar bases during periods of darkness. By finalizing these contracts now, NASA aims to reduce technical risk and maintain the timeline for its upcoming launch.
The SR-1 Freedom reactor utilizes a Sierra Lobo Inc. closed Brayton cycle system, which converts thermal energy from fission into electricity. This setup remains inactive throughout the spacecraft's transit through Earth orbit to ensure safety.
The players
NASA Glenn Research Center
A NASA facility in Cleveland focused on propulsion, energy, and space systems research.
Idaho National Laboratory
A Department of Energy research lab specializing in nuclear energy development and fission reactor design.
Sierra Lobo Inc.
An aerospace engineering firm that develops advanced thermal and power conversion systems for government and commercial space missions.
The details
The mission utilizes a fission reactor designed by the Idaho National Laboratory to generate reliable electricity far from solar sources. Sierra Lobo Inc. is providing the closed Brayton cycle, a thermodynamic process where a gas, such as helium or xenon, acts as a working fluid to drive a turbine and produce electrical power. NASA and the Department of Energy enforce rigorous interagency safety reviews and hazard-focused design processes to manage nuclear risks during the launch and operation phases.
Timeline
2024: NASA awarded the Space Flight Systems Development and Operations Contract III.
- 2026-10-20
NASA announced contract progress for the SR-1 Freedom mission.
Late 2028: Targeted launch date for the SR-1 Freedom mission.
The Tech Race
The SR-1 Freedom mission marks a transition from conceptual research to flight-ready fission power systems. It directly supports NASA's roadmap to deploy nuclear power for future surface missions and sustainable base operations.
The SR-1 Freedom mission serves as the testing platform for technologies that will eventually enable autonomous power for lunar and Martian outposts. Future missions will utilize these validated systems to search for water and sustain long-term research stations.
The takeaway
NASA is moving forward with nuclear power to solve the energy constraints of deep space and lunar missions. Readers should monitor the lead-up to the 2028 launch for updates on the reactor's performance testing and the progress of the three SkyFall Mars helicopters.
Further reading
For broader context on current fission research, visit the Nuclear section.
Live Poll
Should the federal government invest in developing experimental nuclear power systems for future space exploration?
