The small satellite was to map lunar water, but operators lost contact with the spacecraft the day after launch and were unable to recover the mission.
NASA’s Lunar Trailblazer ended its mission to the Moon on July 31. Despite extensive efforts, mission operators were unable to establish two-way communications after losing contact with the spacecraft the day following its Feb. 26 launch.
The mission aimed to produce high-resolution maps of water on the Moon’s surface and determine what form the water is in, how much is there, and how it changes over time. The maps would have supported future robotic and human exploration of the Moon as well as commercial interests while also contributing to the understanding of water cycles on airless bodies throughout the solar system.
Lunar Trailblazer shared a ride on the second Intuitive Machines robotic lunar lander mission, IM-2, which lifted off at 7:16 p.m. EST on Feb. 26 aboard a SpaceX Falcon 9 rocket from the agency’s Kennedy Space Center in Florida. The small satellite separated as planned from the rocket about 48 minutes after launch to begin its flight to the Moon. Mission operators at Caltech’s IPAC in Pasadena established communications with the small spacecraft at 8:13 p.m. EST. Contact was lost the next day.
Without two-way communications, the team was unable to fully diagnose the spacecraft or perform the thruster operations needed to keep Lunar Trailblazer on its flight path.
“At NASA, we undertake high-risk, high-reward missions like Lunar Trailblazer to find revolutionary ways of doing new science,” said Nicky Fox, associate administrator, Science Mission Directorate at NASA Headquarters in Washington. “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. Thank you to the Lunar Trailblazer team for their dedication in working on and learning from this mission through to the end.”
The limited data the mission team had received from Lunar Trailblazer indicated that the spacecraft’s solar arrays were not properly oriented toward the Sun, which caused its batteries to become depleted.
For several months, collaborating organizations around the world — many of which volunteered their assistance — listened for the spacecraft’s radio signal and tracked its position. Ground radar and optical observations indicated that Lunar Trailblazer was in a slow spin as it headed farther into deep space.
“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, Lunar Trailblazer’s project systems engineer at NASA’s Jet Propulsion Laboratory in Southern California. “The global community’s support helped us better understand the spacecraft’s spin, pointing, and trajectory. In space exploration, collaboration is critical — this gave us the best chance to try to regain contact.”
However, as time passed, Lunar Trailblazer became too distant to recover as its telecommunications signals would have been too weak for the mission to receive telemetry and to command.
The small satellite’s High-resolution Volatiles and Minerals Moon Mapper (HVM3) imaging spectrometer was built by JPL to detect and map the locations of water and minerals. The mission’s Lunar Thermal Mapper (LTM) instrument was built by the University of Oxford in the United Kingdom and funded by the UK Space Agency to gather temperature data and determine the composition of silicate rocks and soils to improve understanding of why water content varies over time.
“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,” said Bethany Ehlmann, the mission’s principal investigator at Caltech. “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.”
Some of that technology will live on in the JPL-built Ultra Compact Imaging Spectrometer for the Moon (UCIS-Moon) instrument that NASA recently selected for a future orbital flight opportunity. The instrument, which has has an identical spectrometer design as HVM3, will provide the Moon’s highest spatial resolution data of surface lunar water and minerals.
Lunar Trailblazer was selected by NASA’s SIMPLEx (Small Innovative Missions for Planetary Exploration) competition, which provides opportunities for low-cost science spacecraft to ride-share with selected primary missions. To maintain the lower overall cost, SIMPLEx missions have a higher risk posture and less-stringent requirements for oversight and management. This higher risk acceptance bolsters NASA’s portfolio of targeted science missions designed to test pioneering mission approaches.
Caltech, which manages JPL for NASA, led Lunar Trailblazer’s science investigation, and Caltech’s IPAC led mission operations, which included planning, scheduling, and sequencing of all spacecraft activities. Along with managing Lunar Trailblazer, NASA JPL provided system engineering, mission assurance, the HVM3 instrument, and mission design and navigation. Lockheed Martin Space provided the spacecraft, integrated the flight system, and supported operations under contract with Caltech. The University of Oxford developed and provided the LTM instrument, funded by the UK Space Agency. Lunar Trailblazer, a project of NASA’s Lunar Discovery and Exploration Program, was managed by NASA’s Planetary Missions Program Office at Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.
Karen Fox / Molly Wasser
NASA Headquarters, Washington
202-358-1600
karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
Ian J. O’Neill
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-2649
ian.j.oneill@jpl.nasa.gov
Isabel Swafford
Caltech IPAC
626-216-4257
iswafford@ipac.caltech.edu
2025-099
