Flight hardware development for a space-based robotic assembly and servicing testbed

Abstract

Robotic assembly and servicing missions in space are becoming increasingly attractive for their potential to expand space capabilities and save money. Future missions may construct large systems on-orbit, service existing space assets, or remove retired satellites from valuable locations in the Geosynchronous orbit, among other things. Due to the high-risk nature of these missions, rigorous test facilities are a necessity. This thesis examines the existing testbeds for robotic assembly and servicing technologies and argues that a new, space-based testbed is necessary. It presents initial ground testing results for applicable control concepts, which also indicate that the dynamic authenticity associated with a six-degree-of-freedom on-orbit testbed is crucial for further development. This thesis then presents the requirements for such a testbed and describes the SPHERES Facility on the International Space Station. The facility, created by members of MIT's Space Systems Laboratory, has many of the desired testbed characteristics and can be easily expanded to meet the requirements through a hardware augmentation known as the Halo. The thesis develops the requirements for the Halo and then steps through the conception, design, and implementation of that hardware, along with the planned operations aboard the International Space Station.