29. October 2024 | Press releases:

Water from moon dust: Tests successfully completed Laboratory at TU Braunschweig mimics lunar conditions

Joint press release of TU Braunschweig and the German Aerospace Centre

  • International team tests technologies for extracting water from moon regolith in the laboratory.
  • Laboratory experiments on how ice can be extracted from simulated moon regolith have been successfully carried out at TU Braunschweig.
  • The water obtained could be used as drinking water, for oxygen production or to produce hydrogen-based rocket fuel in space.

The extraction of water in space is of immense importance for research into the solar system. Under the direction of the German Aerospace Center (DLR) in Bremen, the LUWEX research project has developed a process that has now been tested on a large scale at the Technical University of Braunschweig in an experimental phase lasting several months. The aim is to extract at least half a litre of water per experiment.

As part of the LUWEX research project (Validation of Lunar Water Extraction and Purification Technologies for In-Situ Propellant and Consumables Production), scientists have developed a process for extracting and purifying water from moon dust containing ice (regolith) to provide rocket fuel and drinking water for future astronauts stationed on the moon’s surface.

Laboratory conditions simulate the moon

This process has now been successfully tested in experiments. In the experiments, almost 65 percent of the water was extracted from the simulated moon rock and processed. In total, more than three litres of clean water were produced in several experiments. As a partner in the project, the Institute of Geophysics and Extraterrestrial Physics at TU Braunschweig is providing the necessary laboratory infrastructure to test the procedures on a large scale, in great detail and in practical experiments. These experiments enable the validation of the technological setup as well as the identification of potential weaknesses.

The thermal vacuum chamber of the CoPhyLab (Comet Physics Laboratory), a unique facility originally developed for comet research, reflects the conditions on the lunar surface. It allows experiments with dust-ice mixtures at temperatures down to -170 degrees Celsius and under vacuum conditions. A total of 14 measurement systems ensure complete monitoring.

Production of icy lunar regolith in the laboratory

In the CoPhyLab at TU Braunschweig, a dust-ice simulant is mixed with self-produced ice and synthetic lunar regolith, from which the water can then be extracted in the thermal vacuum chamber. For the ice, a mist of very fine water droplets is shock frozen in liquid nitrogen. This produces individual round ice particles with a radius of 2.4 micrometres, which is about one-twentieth of the width of a human hair. These are then mixed with the lunar regolith.

Laboratory conditions simulate the Moon

The lunar ice simulant is then filled into the water extraction system developed by DLR. The system is located inside the thermal vacuum chamber and is tested under moon-like conditions. Up to 15 kilograms of simulant are produced for each series of tests and then filled into a pre-cooled container in the thermal vacuum chamber. The remaining atmosphere is then pumped out and the simulant is heated and stirred to distribute the heat evenly. Due to the low pressure, the ice does not liquefy but is converted directly to water vapour. This gas is then collected on copper pipes cooled to -150°C with liquid nitrogen. Here the gas condenses back to ice. This separates the ice from the lunar regolith. When enough ice has collected on the copper pipes, they are heated and the ice slides down. There it is reheated and liquefied. The DLR Institute of Space Systems in Bremen developed this subsystem for water extraction. At the end of the experiment, the water is processed and its quality checked.

Extracting water under moon-like conditions

Various samples with different proportions of lunar regolith and ice have been tested to identify the optimal process parameters for water extraction. The aim of the project is to extract the maximum amount of lunar water with the least amount of energy. The researchers have been testing the most suitable temperature and stirring speed. In the second step, Thales Alenia Space is responsible for processing and purifying the extracted water. Sensors measure the quality of the water, and samples are analysed in more detail in the laboratory. The goal of extracting at least half a litre of water in each test run has been exceeded. So far, almost 65% of the water added has been extracted and processed.

Collaborative international cooperation

The interdisciplinary LUWEX team from Germany, Austria, Poland and Italy has set itself the goal of developing a novel water extractor. Each participating partner provides one or more subsystems or infrastructures. In addition to TU Braunschweig and DLR, the following institutions and companies are involved in the project: LIQUIFER Systems Group, Thales Alenia Space, Wroclaw University of Science and Technology and SCANWAY SPACE.