Why it matters: NASA's Artemis mission – which seeks to return humans to the moon for the first time in decades – will receive support from the first-ever lunar satellite. An important component of the satellite is a cutting-edge propulsion system that aims to increase power and save energy compared to earlier models.
Early testing has begun on a new solar electric propulsion (SEP) thruster system that will power a NASA satellite in orbit over the moon. The new thrusters are more than twice as powerful as earlier versions.
The Advanced Electric Propulsion System (AEPS) will provide 12 kilowatts of power per thruster compared to the four-and-a-half kilowatts used by prior SEPs. The boost should help NASA craft travel farther and faster. Compared to traditional chemical fuel, SEPs are much more efficient when performing low-level thrust, which gives NASA increased flexibility during the satellite's mission.
Called Gateway, the satellite is a critical component of NASA's Artemis lunar mission. The first stage was an unmanned flyby of the moon that NASA successfully carried out late last year. The next phase, Artemis II, will send a crew into orbit around the moon in May 2024.
Gateway will support the final phase, Artemis III, which aims to put the first humans on the moon's surface since the Apollo missions of the 1970s. The satellite will serve as a logistics hub for transporting science experiments, sample collection tools, and other cargo. Artemis will be only the first leg of Gateway's 15-year mission.
The tests starting this month are considered one of the final steps toward Gateway's completion. First, one of two AEPS prototypes will endure acceptance testing to ensure basic functionality, then stress testing to simulate real launch and flight conditions. Engineers will also collect performance data by hot-firing the thruster before and after each test.
The following testing stage begins next year after NASA and AEPS designer Aerojet Rocketdyne receive the second prototype, which will undergo endurance trials simulating the conditions in lunar orbit. The full testing period will last about four years, involving 23,000 hours of operation.
The three AEPS thrusters that will launch Gateway into space in 2025 are currently being built. Some of the thruster trials will occur after launch to qualify AEPS for future missions.