NASA has terminated the LunaH-Map mission after a stuck valve on the ice-hunting cubesat prevented it from reaching the Moon’s south pole.

The briefcase-sized spacecraft was launched on November 16 last year as part of the Artemis I flight, which was testing the agency’s Space Launch System rocket and Orion capsule in preparation for its next crewed mission to the Moon.

LunaH-Map – or Lunar Polar Hydrogen Mapper – performed a flyby around the Moon but failed to enter the planned orbit. The goal was to study the lunar south pole and to dip to altitudes as low as 10 kilometers (6.2 miles) above the surface to look for ice hidden in regions permanently shadowed by the Sun.

A stuck valve prevented the propulsion system from working properly, meaning it couldn’t change course to get on the right orbit. Mission Control attempted to fix the issue by instructing the cubesat to heat the valve. Despite repeated attempts over six months, the valve did not fully open. NASA ceased operations back in May, and announced the decision this month.

LunaH-Map principal investigator Craig Hardgrove, of Arizona State University, told said in May that the delayed launch of Artemis I because of prolonged bad weather might have contributed to the fault. “We had informed NASA that this propulsion system was not built to withstand a long launch delay,” he is reported to have said.

The mission, under NASA’s SIMPLEx program, hasn’t been a complete flop, however. Lori Glaze, director of the Planetary Science division at the space agency, revealed that its neutron spectrometer worked successfully. The instrument will be installed as part of NASA’s upcoming Lunar-VISE (Lunar Vulkan Imaging and Spectroscopy Explorer) payload that is expected to fly aboard a future spacecraft to the Moon’s surface.

“We are thrilled that the LunaH-Map team was able to use this opportunity to demonstrate the capability of its neutron spectrometer in flight, even though the mission could not be completed as planned,” Glaze declared in a statement. “SIMPLEx missions are inherently risky, as they are designed to test the bounds of what can be achieved with lower-cost missions.”

The cubesat collected nearly three hours of data using its neutron spectrometer from a distance about 1,300 kilometers (807 miles) from the Moon to probe up to one meter below the surface. The spectrometer is designed to probe high-energy neutrons created when cosmic rays strike the atoms in lunar rocks and soil and look for the telltale signs of hydrogen emissions.

Since hydrogen is a core component of water and ice, scientists can get a better sense of the amount of liquid on the Moon and map its frozen deposits. NASA believes the resource will prove useful as future astronauts living and working on the Moon could use the ice to produce air, water, or propellant.

LunaH-Map was one of 10 cubesats launched in the Artemis I flight. Four others malfunctioned and failed to carry out their missions, but the overall mission is regarded as a success