Robots Making Satellites: Advancing In-Space Manufacturing Through On-Orbit Robotic Assembly

Abstract

On-orbit robotic assembly is a critical and necessary advancement for in-space manufacturing. On-orbit assembly missions typically involve humans-in-the-loop and use large custom-built robots to service existing modules. Introducing modularized small satellites (SmallSats) for use cases such as rapid reconstitution of satellite constellation nodes and inspecting damaged assets in Low Earth Orbit (LEO) can accelerate on-orbit robotic assembly capabilities. This thesis introduces and explores the potential of an innovative new approach: the on-orbit autonomous assembly of CubeSats.

The case for small-part robotic snap assembly using CubeSats and low-cost robots and the economic feasibility of the concept are presented. The research gaps which currently limit the on-orbit assembly of CubeSats are (1) the lack of standardization of electromechanical CubeSat modules to be compatible with Commercial-Off-The-Shelf (COTS) robotic assembly hardware, and (2) the assessment and modification of hardware to enable autonomous assembly. Standardization of electromechanical CubeSat modules requires compatibility with low-cost end-effectors. End-effectors must accurately detect and grasp CubeSat components and assemble them using snap assembly attachment mechanisms. Addressing the research gaps, in this work, the robotic assembly of a 1U CubeSat using modular components and COTS robot arms is demonstrated through analyses, simulations, and prototype development. After upgrading the robot system, an XYZ-axis cartesian robot sized at 300 mm x 300 mm x 500 mm is trained and tested using CubeSat subsystem modules for use in a relevant space environment.

The potential for decreasing the lead time for integration and assembly of CubeSats and improving cost savings via more efficient packing volumes and processes motivate the implementation of the proposed on-orbit work. A demonstration mission in which the cartesian robot and SmallSat components are enclosed in free-flying “spacecraft lockers” of approximately 24 inches x 36 inches x 12.5 inches is proposed. CubeSats could be assembled within and deployed from the proposed lockers. The lockers and the CubeSat snap-assembly modules could both have propulsion capability. It is expected that the proposed mission will demonstrate an unprecedented improvement in the build and deployment cycle of SmallSats by reducing the response time from the current minimum of 35 days to less than 10 hours.