Among the executive orders President Trump issued during his last weeks in office was “Promoting Small Modular Reactors for National Defense and Space Exploration,” which builds on the Space Policy Directives published during his term. The order, issued on January 12, calls for actions within the next six months by NASA and the Department of Defense (DOD), together with the Department of Energy and other federal entities. Whether the Biden administration will retain some, all, or none of the specific goals of the Trump administration’s space nuclear policy remains to be seen, but one thing is very clear: If deep space exploration remains a priority, nuclear-powered and -propelled spacecraft will be needed.
The prospects for near-term deployment of nuclear propulsion and power systems in space improved during Trump’s presidency. However, Trump left office days after a hot fire test of NASA’s Space Launch System (SLS) rocket did not go as planned. The SLS rocket is meant to propel crewed missions to the moon in 2024 and to enable a series of long-duration lunar missions that could be powered by small lunar reactor installations. The test on January 16 of four engines that were supposed to fire for over eight minutes was automatically aborted after one minute, casting some doubt that a planned November 2021 Artemis I mission can go ahead on schedule.