On Orbit Servicing (OOS) is a class of robotic space missions that could potentially extend the life of orbiting satellites by fuel replenishment, repair, orbital maintenance or satellite repurposing, and possibly reduce the rate of space debris generation. OOS performed in geostationary orbit poses a unique challenge for the optical space surveillance community. As both satellites would be performing proximity operations in tight formation flight with separations less than 200 meters, atmospheric seeing (turbulence) would prevent resolving a geostationary satellite pair in order to remotely determine the objects' positions. The two objects would appear merged in an image as the resolving power of the telescope and detector, coupled with atmospheric seeing, limits the ability to resolve the two objects. In order to overcome this problem speckle interferometry using a cross spectrum approach is examined as a means to optically resolve the client and servicer's relative positions and enable a means to perform relative orbit determination of the two spacecraft. This paper explores cases where client and servicing satellites are in unforced relative motion flight and examines the observability of the objects. Tools are described that exploit cross-spectrum speckle interferometry to 1) determine the presence of a secondary in the vicinity of the client satellite and 2) estimate the servicing satellite's motion relative to the client. Experimental observations performed with the Mont Mégantic 1.6m telescope on co-located geostationary satellites (acting as OOS proxy objects) are described.

65th International Astronautical Congress 2014: Our World Needs Space, IAC 2014
Department of Mechanical and Aerospace Engineering

Scott, R. (Robert), & Ellery, A. (2014). An approach to ground based space surveillance of geostationary On-Orbit Servicing operations. In Proceedings of the International Astronautical Congress, IAC (pp. 1675–1686).