NASA’s CAPSTONE (Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment) is a CubeSat mission designed to test and verify the calculated orbital stability and navigation capabilities around the Moon. Launched in June 2022, CAPSTONE orbits the Moon in a near-rectilinear halo orbit (NRHO), the same orbit planned for the Lunar Gateway—a future moon-orbiting outpost under NASA’s Artemis program, which aims to return humans to the Moon and establish a sustainable presence there.