Kilopower was a NASA technology-development project investigating compact fission power for long-duration exploration. Led by Glenn Research Center with Marshall and Department of Energy partners, it belonged to NASA’s Game Changing Development Program. Its KRUSTY ground experiment tested reactor operation and Stirling conversion of reactor heat into electrical power at the Nevada National Security Site from November 2017 through March 2018. The completed project also matured heat-pipe technology through flight experiments and developed concepts for lunar power demonstrations. NASA’s later Fission Surface Power Project builds on its results. Kilopower’s ground tests and mission concepts established technology heritage; they did not place a reactor on the Moon.