Launching no earlier than Wednesday, Feb. 26, NASA’s Lunar Trailblazer will help resolve an enduring mystery: Where is the Moon’s water? After sharing a ride on a SpaceX Falcon 9 rocket with Intuitive Machines’ IM-2 launch — part of NASA’s CLPS (Commercial Lunar Payload Services) initiative — the small satellite will take several months to arrive in lunar orbit.
Here are six things to know about the mission.
1. Lunar Trailblazer will produce high-resolution maps of water on the lunar surface.
One of the biggest lunar discoveries in recent decades is that the Moon’s surface has quantities of water, but little about its nature is known. To investigate, Lunar Trailblazer will decipher where the water is, what form it is in, how much is there, and how it changes over time. The small satellite will produce the best-yet maps of water on the lunar surface. Observations gathered during the two-year prime mission will also contribute to the understanding of water cycles on airless bodies throughout the solar system.
Fueled and attached to an adaptor used for secondary payloads, NASA’s Lunar Trailblazer is seen at SpaceX’s payload processing facility within NASA’s Kennedy Space Center in Florida in early February 2025. The small satellite is riding along on Intuitive Machines’ IM-2 launch.
2. The small satellite will use two state-of-the-art science instruments.
Key to achieving these goals are the spacecraft’s two science instruments: the High-resolution Volatiles and Minerals Moon Mapper (HVM3) infrared spectrometer and the Lunar Thermal Mapper (LTM) infrared multispectral imager. NASA’s Jet Propulsion Laboratory in Southern California provided the HVM3 instrument, while LTM was built by the University of Oxford and funded by the UK Space Agency.
HVM3 will detect and map the spectral fingerprints, or wavelengths of reflected sunlight, of minerals and the different forms of water on the lunar surface. The LTM instrument will map the minerals and thermal properties of the same landscape. Together they will create a picture of the abundance, location, and form of water while also tracking how its distribution changes over time and temperature.
3. Lunar Trailblazer will take a long and winding road to the Moon.
Weighing only 440 pounds (200 kilograms) and measuring 11.5 feet (3.5 meters) wide with its solar panels fully deployed, Lunar Trailblazer is about the size of a dishwasher and relies on a relatively small propulsion system. To make the spacecraft’s four-to-seven-month trip to the Moon (depending on the launch date) as efficient as possible, the mission’s design and navigation team has planned a looping trajectory that will use the gravity of the Sun, Earth, and Moon to guide Lunar Trailblazer to its final science orbit — a technique called low-energy transfer.
4. The spacecraft will peer into the darkest parts of the Moon’s South Pole.
Lunar Trailblazer’s science orbit positions it to peer into the craters at the Moon’s South Pole using the HVM3 instrument. What makes these craters so intriguing is that they harbor cold traps that may not have seen direct sunlight for billions of years, which means they’re a potential hideout for frozen water. The HVM3 spectrometer is designed to use faint reflected light from the walls of craters to see the floor of even permanently shadowed regions. If Lunar Trailblazer finds significant quantities of ice at the base of the craters, those locations could be pinpointed as a resource for future lunar explorers.
5. Lunar Trailblazer is a high-risk, low-cost mission.
Lunar Trailblazer was a 2019 selection of NASA’s SIMPLEx (Small Innovative Missions for Planetary Exploration), which provides opportunities for low-cost science spacecraft to ride-share with selected primary missions. To maintain a lower overall cost, SIMPLEx missions have a higher risk posture and lighter requirements for oversight and management. This higher risk acceptance allows NASA to enable science missions that could not otherwise be done.
6. Future missions will benefit from Lunar Trailblazer’s data.
Mapping the Moon’s water supports future human and robotic lunar missions. With knowledge from Lunar Trailblazer of where water is located, astronauts could process lunar ice to create water for human use, breathable oxygen, or fuel. And they could conduct science by sampling the ice for later study to determine the water’s origins.
More About Lunar Trailblazer
Lunar Trailblazer is led by Principal Investigator Bethany Ehlmann of Caltech in Pasadena, California. Caltech also leads the mission’s science investigation, and Caltech’s IPAC leads mission operations, which includes planning, scheduling, and sequencing of all spacecraft activities. NASA JPL manages Lunar Trailblazer and provides system engineering, mission assurance, the HVM3 instrument, and mission design and navigation. JPL is managed by Caltech for NASA. Lockheed Martin Space provided the spacecraft, integrated the flight system, and supports operations under contract with Caltech. The University of Oxford developed and provided the LTM instrument, funded by the UK Space Agency. Lunar Trailblazer, part of NASA’s Lunar Discovery Exploration Program, is managed by NASA’s Planetary Mission Program Office at Marshall Space Flight Center in Huntsville, Alabama, for the agency’s Science Mission Directorate in Washington.