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 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.

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.