A mission architecture and systems level design of navigation, robotics and grappling hardware for an on-orbit servicing spacecraft

On-orbit servicing (OOS) includes a range of servicing types that increase the lifetime of a satellite and its performance, as well as ensuring that it does not contribute to the growing issue of space debris. The avoidance of satellites becoming derelict is particularly important given the rise of ‘mega-constellations’. With the first cases of it in the 1970s, OOS has been achieved many times using crewed missions and robots controlled from the ground or by astronauts, for example during repairs and upgrades to the Hubble Space Telescope (HST) and on the International Space Station (ISS). This has allowed various space agencies and other organisations to mature processes and tools for several OOS mission types. The Northrop Grumman Mission Extension Vehicle-1’s (MEV-1) success servicing Intelsat 901 in early 2020 demonstrated that OOS is now viable from a commercial as well as technical standpoint. However, due to low technology maturity, autonomous rendezvous and proximity operations (RPO) and servicing remain challenging, despite autonomous rendezvous and docking with space stations having been demonstrated many times. This report will investigate the current state of the art in OOS and which technologies require further development to enable widespread adoption of OOS. A mission architecture to support OOS of satellites in the highest populated orbits will be described. Using this architecture, the report will focus on the selection of hardware required for guidance, navigation and control (GNC), for relative navigation towards and docking with the target satellite and of robotics to service the target. The report will use the design of the OneWeb satellites as a baseline for the target spacecraft but will also show how the servicing spacecraft’s services could be applied to a range of orbits and target spacecraft