NASA Eyes New Lunar CubeSat Orbit, Propulsion Challenges Continue

NASA’s Lunar Flashlight CubeSat launched on Dec. 11, 2022, to demonstrate several new technologies with a stretch science goal of detecting surface ice at the Moon’s South Pole. Shortly into Lunar Flashlight’s journey, the mission operations team discovered three of its four thrusters were underperforming.

Among the steps taken to analyze the issue and find possible solutions, the mission performed tests to determine whether the one fully functional thruster could provide adequate thrust to guide the spacecraft into its planned orbit. To that end, team members at NASA’s Jet Propulsion Laboratory in Southern California and Georgia Tech devised a creative maneuvering technique using one thruster: The spacecraft was spun at a rate of 6 degrees per second, or one revolution per minute, around its directed axis. Then the thruster was fired while commanding the spacecraft to remain pointed in the right direction. There was potential after 20 days, these mini-trajectory correction maneuvers would guide Lunar Flashlight to its planned near-rectilinear halo orbit around the Moon.

The team successfully completed quite a few 10-minute sequences on the single thruster, but soon after, that thruster also experienced a rapid loss in performance, and it became clear that the thrust being delivered was not enough to make it to the planned orbit.

The NASA JPL and Georgia Tech team is developing a new plan to get to the Moon. Because achieving an optimal near-rectilinear halo orbit appears unlikely, the Lunar Flashlight team decided to attempt lunar flybys using any remaining thrust the propulsion system can deliver. This new attempt is designed to get the CubeSat into high Earth orbit, which includes periodic flybys of the lunar South Pole once a month to collect data. The team plans to begin maneuvers on Thursday, and, if successful, the expected first science pass will now be in June.

While Lunar Flashlight faces significant challenges in its goal of getting to the Moon, testing its new propulsion system in space fulfills one of the mission’s objectives and will support future technology development. The mission’s miniaturized propulsion system is a technology demonstration that has never been flown in space before. Technology demonstrations are high-risk, high-reward endeavors intended to push the frontiers of space technology. The lessons learned from these challenges will help to inform future missions that further advance this technology.

The rest of the CubeSat’s onboard systems are fully functional, and the mission recently successfully tested its four-laser reflectometer. This mini-instrument is the first of its kind and is designed and calibrated to seek out surface ice inside the permanently shadowed craters at the Moon’s South Pole.

Lunar Flashlight is funded by the Small Spacecraft Technology program in NASA’s Space Technology Mission Directorate.