The German Aerospace Center (DLR) and the European Space Agency (ESA) have jointly built the LUNA research facility in Cologne and officially opened it on September 24, 2024. With its unique equipment and seamless integration into the campus, LUNA is designed to enable the execution of highly complex simulations for human and robotic lunar activities. LUNA will thus add a crucial component to existing global capacities.

Moon network tested

What looks like golden packages on the moon, for example, is not an extraterrestrial gift depot, but a current project in the LUNA hall mentioned above. There, DLR is researching how payload boxes, sensors, rovers and astronauts connect to form a network. In doing so, they exchange signals that can be used for communication and navigation at the same time. “Every robot, sensor or astronaut becomes a participant in a network and passes on information to its neighbors. We determine the distances between the participants by measuring the time it takes for the radio signal to travel between them. With our method, we can determine the exact position of the participants within the network,” explains project manager Dr. Emanuel Staudinger from the DLR Institute for Communication and Navigation. “The system works decentrally, requires no infrastructure and is designed, among other things, for a large number of participants.” The swarm navigation system developed at the institute also makes it possible, for example, to explore the surface of the Moon and Mars. But it also works in lava caves or complex environments on Earth where conventional systems such as satellite navigation are not available.

Many inquiries from a wide range of fields

Emanuel Staudinger and his team have tested the swarm navigation system in recent years on Mount Etna and in a lava cave on Lanzarote. Now, for the first time, swarm navigation has been successfully tested in the LUNA hall, which simulates a realistic lunar environment. “The research center – a joint project of DLR and the European Space Agency ESA – can prepare astronauts and robots for missions on the Moon,” explains Dr. Thomas Uhlig from the LUNA project management. ”Our colleagues from the DLR Institute of Communications and Navigation are among the first to conduct research in our facility. We have now received many requests from a wide range of fields for LUNA. The future will be exciting.”

Robots working together

The scientists from Oberpfaffenhofen have presented several scenarios in the LUNA hall, including this one: a lander arrives on the lunar surface and first deploys two rovers. The first rover has the task of placing radio beacons around the lander. These sensor units immediately take on initial navigation tasks. During its exploratory trips, the rover discovers a crater and finds that it cannot descend into it. It has to call for help from the second rover. The crater is located in an area of the LUNA hall where the floor is lowered by three meters. The second rover finds its way to the crater independently via the navigation system and carries out its scientific investigations. During the journey into the crater, the first rover, from the edge of the crater, assists the second rover with orientation. Another scenario involved deploying sensor units in an area that is too steep for rovers. Up to 50 sensors were distributed and connected to form a network for navigation. Flying units or dropping the sensors into an inaccessible crater were also tested.

3D model of the regolith surface created

In addition to the navigation experiments, the team created a 3D model of the hall and the ground for simulations and to check measurement data. A large part of the LUNA Hall is covered with a layer of regolith simulant ('moon dust'). The mixture has similar chemical, physical and geotechnical properties to the regolith that was brought to Earth by the Apollo missions. The DLR research team will now evaluate the data in detail and further develop the swarm navigation system. The aim is to make this type of robust decentralized navigation and communication available to astronauts and robots exploring the Moon in the future – while also helping with terrestrial exploration of difficult terrain.

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