Three years after the project was first announced, the Clean Space One Project has passed a milestone, the completion of the prototype stage. École Polytechnique Fédérale de Lausanne also unveiled details of the plan to send a satellite into space to scoop up space junk.
The team of scientists are working on launching a space clean-up satellite into orbit, with the aim of capturing the SwissCube satellite, which has been orbiting Earth for over five years, and destroying it in the atmosphere.
The project is not without challenges, explains Christophe Paccolat, a PhD student working in LTS5:
“SwissCube is not only a 10cm by 10cm object that’s tough to grasp, but it also has darker and lighter parts that reflect sunlight differently. These variations can perturb the visual approach system and thus also the estimates of its speed and distance.”
Project head Muriel Richard-Noca, adds: “It only takes one error in the calculation of the approach for SwissCube to bounce off CleanSpace One and rocket out into space.”
Currently, the visual approach algorithms on the cleanup satellite’s cameras are being tested, to ensure the team avoids these kinds of disasters. To be accurate, they must take into account multiple parameters, such as the angle of illumination of the Sun, the physical data of the SwissCube, the relative speed at which it is moving and all the uncertainties involved in this measurement, and the speed of its own rotation.
The space clean-up satellite, in collaboration with Payerne-based S3, is scheduled for launch as early as 2018.
Engineers benefited from the collaboration of microengineering students from Hepia Geneva, member of the HES-SO University of Applied Sciences and Arts Western Switzerland, in their quest to design the most efficient capture system.
Students brainstormed various solutions, from articulated arms with claws to a system of tentacles. They finally opted for the so-called “Pac-Man” solution.
The prototype looks like net in the form of a cone that unfolds and then closes back down once it has captured the small satellite.
“This system is more reliable and offers a larger margin for maneuvering than a claw or an articulated hand,” says Michel Lauria, professor of industrial technology at Hepia.
The team will next evaluate the first version of the engineering models.
Illustration: © 2015 EPFL/Jamani Caillet