WASHINGTON — NASA has formally ended a lunar orbiter smallsat mission more than five months after losing contact with it, another blow to the agency’s efforts at low-cost planetary missions.
NASA announced Aug. 4 that the agency officially ended the Lunar Trailblazer mission on July 31. The spacecraft had been out of contact with ground controllers since the day after its Feb. 26 launch as a secondary payload on the Falcon 9 carrying the Intuitive Machines IM-2 lunar lander.
The data that controllers did receive from the spacecraft indicated the spacecraft was in a slow spin and unable to properly align its solar arrays, depleting its batteries. Mission managers hoped that, as the spacecraft flew into deep space, its changing orientation with respect to the sun might enable the panels to generate more power and restore communications.
“As Lunar Trailblazer drifted far beyond the Moon, our models showed that the solar panels might receive more sunlight, perhaps charging the spacecraft’s batteries to a point it could turn on its radio,” said Andrew Klesh, project systems engineer for Lunar Trailblazer at the Jet Propulsion Laboratory, in a statement. He thanked a global community of ground station operators for their efforts to track the spacecraft and listen for any signals.
At the end of April, NASA said it would continue efforts to restore contact with the spacecraft until mid-June. Two months later, the agency said it would extend those efforts through early July, then “assess any remaining options, including closing out the mission.” That was the last update from NASA on Lunar Trailblazer until the Aug. 4 statement.
The NASA announcement did not disclose the root cause of the spacecraft’s inability to properly orient its solar panels. The 200-kilogram spacecraft was built by Lockheed Martin.
Lunar Trailblazer was designed to go into orbit around the moon, mapping the amount and form of water ice on the moon with two instruments, an imaging spectrometer and thermal mapper. A version of the spacecraft’s imaging spectrometer, called the Ultra Compact Imaging Spectrometer for the Moon, was selected by NASA last month for development to go on a future, unspecified lunar orbital mission.
“We’re immensely disappointed that our spacecraft didn’t get to the moon, but the two science instruments we developed, like the teams we brought together, are world class,” Bethany Ehlmann, principal investigator for Lunar Trailblazer, said in a statement. “This collective knowledge and the technology developed will cross-pollinate to other projects as the planetary science community continues work to better understand the moon’s water.”
More risks than rewards
In the statement announcing the end of the mission, NASA shrugged off the loss of Lunar Trailblazer as an aspect of attempting inexpensive planetary missions.
“At NASA, we undertake high-risk, high-reward missions like Lunar Trailblazer to find revolutionary ways of doing new science,” Nicky Fox, NASA associate administrator for science, said in the statement. “While it was not the outcome we had hoped for, mission experiences like Lunar Trailblazer help us to learn and reduce the risk for future, low-cost small satellites to do innovative science as we prepare for a sustained human presence on the moon.”
The success of the twin Mars Cube One, or MarCO, cubesats that accompanied the InSight lander to Mars and relayed telemetry in 2018 raised hoped that cubesats and other smallsats might enable low-cost missions to the moon, Mars and other inner solar system destinations. But NASA has had a poor record of success on such missions since then.
NASA’s Small Innovative Missions for Planetary Exploration, or SIMPLEx, program supported the development of several such missions, starting with the cubesat-class Q-PACE and LunaH-Map. Q-PACE, designed to measure particle interactions in microgravity to assist modeling of protoplanetary disks, was not heard from after its launch into Earth orbit in 2021. LunaH-Map launched as a secondary payload on Artemis 1 in 2022 but suffered a failure of its propulsion system that prevented it from going into lunar orbit as planned.
In 2019, NASA selected three smallsat missions for development as part of SIMPLEx, including Lunar Trailblazer. A second mission, Janus, was to fly by binary asteroids, launching as a secondary payload on the Psyche mission. Delays in Psyche, though, meant that Janus could no longer reach suitable destinations. NASA formally canceled the Janus mission in 2023 and put the completed spacecraft into storage at the Langley Research Center.
Some have proposed repurposing the Janus spacecraft to visit the asteroid Apophis ahead of its close flyby of Earth in 2029. Dan Scheeres, principal investigator of Janus, said at a June 25 meeting of the Small Bodies Assessment Group that using Janus for Apophis or other asteroid flybys was feasible, but the spacecraft would require some reassembly, testing and “rework” of some components.
The third SIMPLEx mission selected in 2019, ESCAPADE, has yet to launch on its mission to Mars. It was to fly on the inaugural Blue Origin New Glenn launch, but taken off in September 2024 when NASA concluded the rocket would not be ready in time to meet an October launch window. Blue Origin announced July 17 ESCAPADE will go on the second New Glenn, but the company has not set a launch date other than no earlier than Aug. 15. Industry sources expect a launch some time this fall.
In addition to the problems with SIMPLEx missions, several other deep space smallsat missions run or funded by NASA, launched alongside LunaH-Map on Artemis 1, suffered failures. They included NEA Scout, which planned to deploy a solar sail to enable it to go to an asteroid; Lunar IceCube and Lunar Flashlight, which planned to look for water ice at the moon; and CuSP, a solar science mission.
There have been a few successes. BioSentinel, another cubesat launched on Artemis 1, continues to operate more than two and a half years after launch, collecting data on how radiation affects microorganisms. CAPSTONE, a NASA-funded smallsat mission run by Advanced Space, launched in June 2022 and is still operating in a near-rectilinear halo orbit around the moon.
NASA has not solicited proposals for additional SIMPLEx missions since the selection of ESCAPADE, Janus and Lunar Trailblazer. The agency cited funding constraints that have also delayed plans for larger Discovery and New Frontiers planetary science missions.