01 Jul 2020
Research project in which moondust is laser-melted under lunar conditions suggests moon-based manufacturing is feasible.Laser Zentrum Hannover (LZH) together with the Institute of Space Systems (IRAS) of the Technical University of Braunschweig carried out this unique experiment in the Einstein-Elevator at the Hannover Institute of Technology at the Leibniz University Hannover.
"With these spheres, we have come a big step closer to 3D-printing on the moon," commented Niklas Gerdes, a scientist at LZH. A laser system developed by the LZH was used to melt synthetically produced lunar dust, the so-called regolith, under both lunar and microgravity conditions simulating the process as it might happen on the moon.
Material samples adapted to possible landing site
IRAS scientists have compiled the material samples for the experiments. "Depending on the landing site of a possible lunar mission, the composition of the lunar dust varies," said Prof. Dr.-Ing. Enrico Stoll from IRAS.
The melting of the regolith was the first scientific experiment in the new Einstein-Elevator located at the LUH. The laser system and a vacuum chamber in the gondola of the elevator were attached to an experiment carrier prior to operation in the elevator.
The experiment carrier supplies the laser system with power and enables the controls over the system. The regolith samples are held in a vacuum during the experiments – just as they would be on the moon. During the flight, the laser melts a small amount of regolith, forming a sphere that cools down before landing in the experiment chamber.
Prof. Dr.-Ing. Ludger Overmeyer, of LUH, described the special features of the large research device from Hannover as follows: "The Einstein-Elevator is equipped with long-stator linear motors. This enables us to accelerate and set a vertical trajectory precisely, but also to brake it safely. In this way, we can achieve up to 300 flight attempts per day and also varying degrees of gravity."
Microgravity, i.e. weightlessness, is achieved in free fall, while lunar gravity is generated when the elevator is slowed down. "This is unique to date and makes it possible to carry out statistical tests in different gravitational environments," said Prof. Dr.-Ing. Overmeyer.
"The next goal is now to test the laser system on a lunar mission," said Stefan Linke, of IRAS. "If the laser system can be used to melt regolith on the moon, 3D-printed construction material on the moon will come closer and with it the realization of the vision of a lunar colony."
The Volkswagen Foundation supports the ambitious and future-oriented research project within the funding initiative of “Open – for the Unusual". The foundation supports extraordinary and daring projects for which no other financing can be found.
The Einstein-Elevator at the Hannover Institute of Technology of Leibniz University Hannover is an actively controlled drop tower of a new generation. It enables experiments in weightlessness and other gravity conditions such as lunar or Martian gravity at a repetition rate of up to 300 runs per day in a three-shift operation.
The facility was commissioned in autumn 2019 and had already successfully completed its first research flights for the Moonrise project and other research projects. The Institute of Transport and Automation Technology works in close cooperation with LZH on laser-based additive manufacturing under space conditions.