Water extraction from Moon rocks advances for astronaut support

Water extraction from Moon rocks advances for astronaut support
by Robert Schreiber
Berlin, Germany (SPX) Oct 30, 2024

Water extraction in space is critical for expanding human exploration of the Solar System. Led by the German Aerospace Center (DLR), a new technique is being validated to harvest water from the Moon. Through the LUWEX research project, dedicated to testing lunar water extraction and purification for in-situ resource use, researchers at the Technical University (TU) Braunschweig have conducted large-scale experiments over several months. The trials aim to produce at least half a liter of water per run.

The LUWEX project's primary objective is to develop and test a method for extracting and purifying water from lunar regolith containing ice. This process could supply both drinking water and rocket fuel for future Moon missions. Recently, the technique has shown promising results in experimental conditions.

Paul Zabel, from the DLR Institute of Space Systems in Bremen, shared his enthusiasm: "We exceeded our goal of producing at least half a litre of water in each test run. In the experiments, we were able to extract and process almost 65 percent of the water from the simulated Moon rock. In several experiments, we produced a total of more than three litres of clean water."

The process at TU Braunschweig involved creating a dust-ice simulant by mixing synthetic lunar dust with ice produced through a specialized freezing method. Fine water droplets, misted and shock-frozen in liquid nitrogen, formed water ice particles only 2.4 micrometres in radius - about one-twentieth of a human hair's width. This ice was then combined with lunar regolith simulants to replicate Moon-like conditions.

Simulating the Moon's environment, the lunar ice simulant was placed within DLR's thermal vacuum chamber-based water extraction system. After removing the atmosphere, the simulant was heated and stirred to distribute heat uniformly. Due to low pressure in the chamber, the ice didn't melt; instead, it sublimated into vapor, which condensed into ice on copper pipes cooled to minus 150 degrees Celsius by liquid nitrogen. The ice then accumulated and was subsequently melted to produce liquid water. Developed at DLR's Bremen site, this subsystem refined the water extraction method further.

Testing involved multiple regolith and ice ratios to pinpoint optimal extraction parameters, such as ideal temperature and stirring rates. Thales Alenia Space oversaw the water purification stage, monitoring water quality with sensors and analyzing samples for quality assurance.

"This allowed us to successfully demonstrate how the overall system works under different conditions. This is an important step in the development of technologies for future lunar missions," said Zabel.

The LUWEX project brings together an interdisciplinary team from Germany, Austria, Poland, and Italy, each contributing subsystems or specific infrastructures. Partners include DLR, TU Braunschweig, LIQUIFER Systems Group, Thales Alenia Space, Wroclaw University of Science and Technology, and Scanway Space.