DEVELOPING A RELIABLE CAPTURE SYSTEM FOR CLEANSPACE ONE

The objectives of the CleanSpace One mission are to raise the awareness of the orbital debris problem, develop and test technologies for non-cooperative rendezvous and as a demonstration, de-orbit the SwissCube satellite. Within this project and over the last few years, several capture systems have been prototyped, from robotic grippers to nets to more conventional capture mechanisms. A major trade-off was performed end of 2014 taking into account system, operational, reliability, functionalities, cost, manufacturability and local expertise criteria. This exercise led to the selection of a deployable “pacman” mechanism. Since then, two iterations of prototypes have been manufactured, with different deployment and closing concepts. This paper describes the latest design. It first presents capture system requirements, including concept of the capture scenario. The capture system trade-offs and selection are then discussed. The main section describes the capture mechanism analyses and design. Analyses especially focus on the cross section and geometry of the elements to ensure successful capture. In the current design, five deployment units unfold bi-stable reeled composite booms. The deployment units use harmonic drives to reduce volume and mass. The synchronized closing of the Pacman is achieved by a closed loop cable linked to a single linear actuator. A complete design of the deployment units has been created to validate the concept. A prototype of one deployment unit has been manufactured. Preliminary tests of the net between the deployable booms have been done. First prototype of the vision-based system that will drive the closing command and confirm capture is discussed. The capture prototypes work well and thus demonstrate the feasibility of the mechanism.