The active removal of space debris has great interest nowadays because of recent events of space collisions in LEO and unexpected object re-entry. There have been some test flights, e.g. ETS-VII  and Orbital Express , for on-orbit satellite servicing and autonomous rendezvous and docking, with the advantage of being cooperative targets, which gives aid for attitude and position determination by the chaser. In case of space debris, no cooperative information is given and the chaser satellite must extract accurate information about the behaviour of the tumbling debris. For this, specific sensors will be used during each phase of the rendezvous approach in order to ensure a secure and safe mission during the complete process. The purpose of this paper is to describe the use of possible sensors for autonomous rendezvous to space debris, i.e. non-cooperative targets.