A Novel Navigation and Sensor Strategy for Far, Mid and Close Range Rendezvous to a Cooperative Geostationary Target Spacecraft

Abstract

In this article, we propose a novel concept for rendezvous to a geostationary target spacecraft. For an approach to a cooperative target in the geostationary orbit (GEO), we develop a strategy for far, mid and close range rendezvous. The concept of the iBOSS project (Intelligent Building Blocks for On-Orbit Satellite Servicing) serves as reference scenario, where a servicing satellite with rendezvous and berthing capability approaches a client satellite in GEO for possible payload manipulation or lifetime extension. In our work, we assume a scenario similar to the iBOSS case. We assume the client to be a cooperative, geostationary communication satellite which is attitude-stabilized. Different rendezvous sensors and equipment are analyzed for suitable use during a mission like iBOSS. The selected rendezvous concept is based on a camera system which consists of three cameras with different field-of-view to cover all rendezvous phases. During the entire approach, it has to be ensured, that the intensity of the light reflected by the target or emitted at the target's surface and received by the camera is large enough such that the target is visible in the camera images. In a detailed visibility analysis, we estimate the magnitude of the irradiance of the light received by the camera. Further, we present methods for relative navigation during far, mid and close range rendezvous. The results of the visibility analysis and a performance evaluation of the proposed navigation methods show that the presented concept can be employed for rendezvous to a cooperative target in GEO.