In May, CAPSTONE successfully tested navigation technology similar to Earth’s GPS for the first time, expanding capabilities that could help future space missions navigate the moon more efficiently. The spacecraft also took the first images of the moon as CAPSTONE approached the moon on May 3, showing the lunar surface near the moon’s north pole.

CAPSTONE, short for Cislunar Autonomous Positioning System Technology Operations and Navigation Experiment, is a microwave-sized CubeSat that flies in a unique elliptical lunar orbit that Gateway will use. Two spacecraft participated in the CAPS mission technology tests: CAPSTONE and NASA’s Lunar Reconnaissance Orbiter (LRO). During the May 9 experiment, CAPSTONE sent a signal to the LRO designed to measure the distance and relative velocity between the two spacecraft. The LRO then sent the signal back to CAPSTONE, where it was converted into a measurement. The test demonstrated the ability to collect measurements to be used by the CAPS software to determine the position of both spacecraft. This capability could provide autonomous onboard navigation information for future lunar missions.

In addition to the successful CAPS test, CAPSTONE also achieved another mission goal of flying in a nearly linear halo orbit for at least six months. This marks the end of the spacecraft’s primary mission, and CAPSTONE will continue to orbit and test onboard technologies for a year during the extended phase of the mission.