First successful demonstration for the robots of the future Lunar Village
The European Space Agency plans to organize a mission in 2025 to show the feasibility of using lunar resources. The exploration can only be carried out by robots capable of cooperating. A first simulation has just been successfully carried out.
Among the robots in development at the European Space Agency (ESA), those capable of cooperating will play a key role in future space exploration missions, including missions to Mars.
Announced in 2015 by former European Space Agency (ESA) Director Jan Wörner, the Moon Village, a utopian vision of a human and/or robotic lunar base, is now taking shape. ESA plans to launch the first In Situ Resource Utilization (ISRU) demonstration mission to the Moon in 2025. At the beginning of April 2021, the robotic platform in charge of this mission has just proven itself in an analog environment.
Robots to prepare lunar outposts
To stay on the Moon, humans will need resources: water, oxygen and building materials to make their habitat. However, it would be too costly to transport these raw materials from Earth by spacecraft; it is therefore preferable to use the resources present on site (in situ). Only robots can exploit these resources before the arrival of humans. Oxygen extracted from lunar regolith can be used as an oxidizer to make fuel and to generate artificial atmosphere in habitats; regolith will also be used as a building material for housing structures that will be 3D printed.
The ISRU facilities would thus serve as outposts and would also deliver hydrogen and oxygen to various points in lunar space.
A European consortium
This mission was assigned to the project called PRO-ACT (Planetary Robots Deployed for Assembly and Construction Tasks), which was tasked with implementing the cooperation of several robotic systems to perform different tasks (including site preparation) on a lunar mission and demonstrating their functionality in a lunar mission scenario.
Initiated on February 1, 2019, the project was completed as planned at the end of March 2021, despite difficulties related to the coronavirus pandemic, which did not allow for joint testing. PRO-ACT is in fact the product of the collaboration of a European consortium under the leadership of the Belgian company Space Applications Services NV/SA; this consortium includes a total of nine European companies and institutions from six countries (Belgium, France, Germany, Spain, Great Britain and Poland).
Funded by the European Commission, the PRO-ACT project is part of the second phase of the Space Robotics Technologies Research Cluster under the PERASPERA (Plan European Roadmap and Activities for Space Exploitation of Robotics and Autonomy) call of the Horizon 2020 program.
Three complementary robotic systems
The multi-robotic platform on which the project is based consists of three robots capable of cooperating:
● The six-wheeled VELES rover, manufactured by the Polish Institute for Industrial Research on Automation and Measurement (PIAP), is capable of traveling long distances and carrying particularly heavy payloads with its gripper arm.
● The six-legged walking robot, Mantis, built by the German Research Center for Artificial Intelligence (DFKI) in Bremen, can grasp and lift objects with its front legs, which also serve as arms. It can also carry objects with another type of robot (in this case the VELES rover). Thanks to the sensor integrated in its head, it is able to detect its environment and to decide its movements autonomously.
● The mobile gantry from Spanish company AVS can be assembled or disassembled with the support of Mantis and VELES. Featuring an integrated 3D printer, which it can move using a cable control system, it will have two uses: printing structural elements for assembly and construction of human habitats, and dust removal.
After 27 months of work, the feasibility tests were able to take place indoors and outdoors at the DFKI in Bremen and the PIAP in Poland, in an environment analogous to the lunar environment. This virtual demonstration had to be conducted remotely due to health regulations prohibiting travel to Europe.
In order to respect the lunar environment as closely as possible, the demonstration site included boulders, slopes of various degrees and a crater; light, dark and dry conditions were also controlled.
In the inner halls of the DFKI and PIAP, Mantis and VELES explored the terrain simultaneously and autonomously, mapping the environment in a cooperative manner. Supervised by the control station developed by the Belgian company Space Applications Services, their operations were coordinated in real time by the planners of the Spanish group GMV.
Remotely controlled by the Belgian station, the mobile gantry located in the AVS premises in Spain simulated the printing of components for the assembly of the ISRU installation with lunar regolith. To replace it, the simulant 1 of the European Astronaut Center was not retained, because it is very dusty and dangerous for the health inside. Therefore, sand from the Baltic Sea was chosen, which has relevant geomorphological conditions and also corresponds to lunar conditions.
Finally, in the LAAS-CNRS laboratories in France, the two Pandas robotic arms have demonstrated their cooperative manipulation capabilities.
The usefulness of this demonstration
In the PRO-ACT project, the software and algorithms were tested on simulated robots before being implemented on “real” systems, allowing program errors to be detected and possibly corrected at an early stage. Since the demonstration was carried out entirely virtually and remotely, the consortium partners also gained experience in teleoperation, which will be of great use for future planetary space missions.
As the PRO-ACT project is part of the second phase of the Strategic Research Cluster (SRC) “Space Robotics Technologies”, the consortium has built on the research from previous projects by further developing and adapting it to this specific mission. The next mission of this Research Cluster pursues the same goal: the CoRob-X project, launched in March 2021 under the leadership of the DFKI Robotics Innovation Center, aims to have a team of robots cooperate with the goal of exploring lava tunnels on the Moon.