A new nuclear energy system that would power space flights has just passed a series of crucial tests in the Nevada desert. The Kilopower Reactor Using Stirling Technology (KRUSTY) experiment could create fission-powered electricity in a stable and reliable manner—regardless of what environment it operates in.
The Kilopower project aims to create an affordable fission nuclear power system that can enable long-duration stays on the Moon, Mars and destinations beyond.
KRUSTY is a small, lightweight fission power system that can provide up to 10 kilowatts of electrical power—sufficient to run an entire household continuously for at least a decade. Four such units could power an outpost on the Moon or another planet.
The KRUSTY prototype uses a solid, cast uranium-235 reactor core about the size of a paper towel roll. Passive sodium heat pipes transfer heat from the reactor to high-efficiency Stirling engines, which convert the heat to electricity.
The Kilopower team conducted the experiment from November 2017 through March 2018 in four phases. The first two phases were conducted without power and confirmed that each component of the system performed as it should. During the third phase, the team increased power incrementally to heat the reactor core. The final phase consisted of a full power test of a simulated mission, including reactor startup, ramp to full power, steady operation and shutdown.
Throughout the experiment, the team simulated problems such as power reduction, failed engines and failed heat pipes. With each scenario, the system demonstrated that it could continue operating during multiple failures and manage them successfully.
Engineers lower the wall of the vacuum chamber around the KRUSTY system.
“We threw everything we could at this reactor … and KRUSTY passed with flying colors,” said chief reactor designer David Poston of the Los Alamos National Laboratory.
The NASA team is developing mission concepts and additional risk reduction measures to prepare for a possible future flight demonstration—which could open the door for future Kilopower systems that would power human outposts. Such a system would be essential on the Moon, where nights can last longer than two weeks and render solar power unreliable.
Traditionally, spacecraft have used the heat from plutonium-238 that was the byproduct of Cold War-era nuclear weapons production. That production ended in the late 1980s, and supplies are currently running low. Kilopower could provide a viable alternative to that plutonium.
“Safe, efficient and plentiful energy will be the key to future robotic and human exploration,” said Jim Reuter, NASA’s acting associate administrator for the Space Technology Mission Directorate. “I expect the Kilopower project to be an essential part of lunar and Mars power architectures as they evolve.”
Read more about space exploration at NASA Returns to Mars with New InSight Lander.