Water ice detection campaign prepares lunar robots for Moon mission

by Robert Schreiber
Berlin, Germany (SPX) Nov 18, 2025

Researchers in Germany have conducted a campaign at the LUNA Analog Facility in Cologne to evaluate how water ice could be located and mapped on the Moon. Instruments and robotic vehicles were used in a simulated lunar environment with a substantial area covered in regolith material similar to Moon dust.

The Polar Explorer campaign at LUNA tested the mobility and sensing abilities of two rover units equipped with radar, spectroscopic, and seismic instruments. Nicole Schmitz from the DLR Institute of Space Research noted that combining varied detection methods greatly improves reliability in mapping water ice. Preliminary analysis confirms that the rovers successfully identified and mapped simulated subsurface water ice.

One approach used radar instruments that detected simulated "ice" objects concealed within three meters of regolith. Seismic methods provided additional data with fibre-optic cables laid to capture ground vibrations, enabling distributed acoustic sensing to map underground features.

The campaign also measured hydrogen content in rock samples using Laser-Induced Breakdown Spectroscopy (LIBS). LIBS generates a plasma cloud that reveals elemental composition by analyzing the resulting light spectrum. The spectrometer operated on a robotic arm integrated with one rover.

Surface mapping was performed using a multispectral stereo panoramic camera that records data in wavelength bands extending beyond human vision. These systems will help future lunar missions document mineral composition, predict terrain, and select safe routes for rover navigation.

Ground-penetrating radar mounted on a trailer provided a three-dimensional understanding of the simulated lunar area, integrating subsurface and surface mapping. The Polar Explorer mission rehearsal combined all planned operational steps and validated overall system readiness for space deployment.

The two rover units previously participated in field exercises on Mount Etna in Italy and have demonstrated autonomous operations, obstacle avoidance, and instrument deployment under challenging lighting conditions at LUNA. Experiments simulated sunlight angles found at the Moon's poles using a hall light array.

Current scientific theories suggest lunar water ice could result from comet and micrometeorite impacts, solar wind interactions, or ancient volcanism. Schmitz said, "Scientists used to agree that the Moon was bone dry. Now we have lots of evidence that there is water ice on the Moon - and at the same time lots of unanswered questions. It's extremely exciting." Studying lunar water ice may provide insight into solar system evolution.

Accessible water ice is critical for sustained exploration activities on the Moon. It is necessary for drinking water and can be split into hydrogen and oxygen for rocket fuel production.