SKYWALKER tests robotic crawling at ESTEC
As part of the ESA Academy Experiments programme, the SKYWALKER student team from Aalborg University, Denmark, successfully tested a smart algorithm to help a robotic arm on a floating platform move in microgravity-like conditions. The test campaign took place in late September 2025 at ESA ESTEC’s Orbital Robotics Lab. This work is paving the way for future robots to operate independently in space—building, repairing, and maintaining structures.
The SKYWALKER team from Aalborg University was selected in February 2025 to join the ESA Academy Experiments programme. The team developed two algorithms to enable a robotic arm to learn how to “crawl” in simulated microgravity conditions. One algorithm allows the robotic arm to find an anchor point and to anchor itself, and the other to drag the floating base by moving the arm while anchored. The first reinforcement learning algorithm worked successfully during testing, while the second encountered challenges when moving from simulation to real hardware.
Before the test campaign at ESA, SKYWALKER students trained the algorithms through simulations and then carried out pre-tests using a robotic arm and a platform they built themselves at university. After that, thanks to ESA Academy Experiments programme, the team had the chance to test their work at the Orbital Robotics Lab, at ESTEC in the Netherlands, with ESA experts. This facility has Europe’s flattest floor, designed to simulate a two-dimensional microgravity environment.
At the Orbital Robotics Lab, the team first set up their robotic arm on the MANTIS floating platform and connected it to the VICON motion capture system to run the initial tests. Then, students tested the two reinforcement learning algorithms separately. During this second test, one of the two algorithms had trouble working on the real hardware, producing results that differed from the earlier simulations. After investigating and comparing the simulated environment with the lab setup, the students found the issue, which they plan to fix back at their university.
Despite some technical challenges, the SKYWALKER team successfully demonstrated the system's full crawling motion, combining the robotic arm and floating platform, on the Orbital Robotics Lab's frictionless floor. The team is proud of the progress achieved: one algorithm successfully enabled the robot to anchor autonomously, and they now have a clear plan to refine the second algorithm thanks to what they learned during hands-on testing.
Thanks to the test campaign at ESTEC, the students gained valuable hands-on experience moving from simulations to real hardware and adapting to different lab conditions. The SKYWALKER project continues to move forward, with one recent graduate now working full-time on this important research to make autonomous crawling in microgravity a reality.