I'm referring to the Lunar Flashlight, a cubesat launched in December by SpaceX, on the same mission as the ispace Hakuto-R M1 carrying the Rashid lunar lander by the United Arab Emirates.
I haven't been watching carefully for updates, and found out as part of today's story that Lunar Flashlight has had problems with its propulsion system thrusters since it launched. It currently looks like the probe will not be able to get to its intended Near Rectilinear Halo Orbit and there looks to be a pretty good chance the mission will never achieve its goal of looking for water ice in craters around the lunar south pole. NASA/JPL (and others) have been working to get the thrusters working but are saying that if they don't get it fixed by the end of April it's probably all over for the mission.
... on the way to the moon, the cubesat experienced thruster glitches on its mission to test a new "green" propellant. NASA officials downgraded its mission from orbiting to lunar flybys weeks ago. Yet the amended mission remains uncertain, agency officials said on Thursday (March 23).
"The operations team has been working on ways to restore partial operation of one or more thrusters to keep the spacecraft within the Earth-moon system," NASA officials stated in a blog post.
By early February, engineers at JPL and Georgia Tech had developed a novel way to use one working 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.
By later in February, the team decided to switch their emphasis to getting the existing thrusters to work well enough to keep the Lunar Flashlight in Earth orbit with a high enough apogee to image the moon's south pole region once a month. They have had some success but are still trying to overcome the thruster problems.
The rest of systems on the spacecraft continue to work as intended and the
mission has met all of its other objectives short of studying the lunar south
pole region. The new technology "green propellant" is a technology
demonstration that has never flown before. Demonstrations like
this are always high-risk, high-reward endeavors intended to push the
envelope of space technology. The lessons learned from this mission will be
part of developing the new technology, if it's deemed worth spending more
An artist's depiction of Lunar Flashlight looking for ice in a crater on the moon. (Image credit: NASA/JPL-Caltech)
For more on the Lunar Flashlight,
there's this pdf from JPL.