by Lockheed Martin has been granted a $33.7 million contract by the Air Force Research Laboratory (AFRL) to design a nuclear-reactor-powered spacecraft for the Joint Emergent Technology Supplying On-Orbit Nuclear (JETSON) High Power program. As space missions venture further into the outer solar system and mission durations extend over longer periods, alternative methods of powering and propelling spacecraft are necessary. Chemical rockets and solar panels, which have been the primary sources of power for space missions for decades, have their limitations when it comes to missions beyond Jupiter.
Any missions that travel beyond Jupiter’s orbit require the use of some form of nuclear power to operate their systems. Chemical rockets in that region can only provide propulsion by limiting payloads and utilizing complex slingshot orbits to build up the necessary velocity to reach their destination.
Lockheed Martin is partnering with Space Nuclear Power Corp (SpaceNukes) and BWX Technologies, Inc. (BWXT) to develop the JETSON spacecraft. The project has reached the preliminary design stage, with the possibility of a critical design review if approved. The objective is to combine a nuclear fission reactor with Lockheed’s LM2100 satellites’ electric propulsion Hall thrusters.
The JETSON spacecraft currently features a reactor within the probe’s box, with a fan of radiators positioned behind it. To ensure the maximum distance from the radioactive power source, there is a boom that extends to keep the electronics and Hall thrusters distant from the reactor.
The reactor utilized in the JETSON spacecraft is based on NASA and the US Department of Energy’s 2018 Kilopower Reactor Using Stirling Technology (KRUSTY) demonstration. It utilizes a solid-cast uranium 235 reactor core measuring 6 inches (15 cm) in diameter for fuel, with a beryllium oxide reflector surrounding it. Starting and stopping the reactor is facilitated by a single rod of boron carbide, while the reflector captures escaping neutrons and redirects them back into the core.
For safety reasons, the reactor remains switched off until the spacecraft is in a secure orbit. Once activated, the heat generated by the reactor is utilized to power a bank of Stirling heat engines. The engines work by compressing and expanding gas in a closed cycle, producing up to 20 kWe of power—over three times more than traditional spacecraft solar panels. This significantly enhances the longevity of deep-space probes and provides power for Hall thrusters, which can gradually accelerate spacecraft to velocities sufficient for escaping the solar system or visiting various destinations.
According to Barry Miles, the JETSON program manager and principal investigator at Lockheed Martin, the development of nuclear fission for space applications could revolutionize space exploration and transportation. Lockheed Martin is committed to collaborating with government agencies and industry partners to advance high-power electrical subsystems, electric propulsion, nuclear thermal propulsion, and fission surface power technologies.
By developing a nuclear-reactor-powered spacecraft, Lockheed Martin aims to provide a solution for powering deep-space missions that go beyond Jupiter’s orbit. This innovative technology has the potential to propel space exploration into new frontiers and revolutionize how we navigate and explore the vastness of space.
