Toward the Autonomous Assembly of Large Telescopes Using CubeSat Rendezvous and Docking

This paper describes the results of a system study for the in-space assembly of large optical telescopes using a building block approach involving multiple mirror segments. Such an approach is enabled by CubeSat rendezvous and docking and mirror steering technologies for compensating misalignment of the assembly. This concept thus removes the constraints imposed by the limited volume of launchers’ fairing, and hence larger telescope dimensions can be envisaged, leading to new observation capabilities. Each mirror segment is mounted on top of a small satellite, containing the miniaturized subsystems to achieve autonomous docking to either the service module containing the science instruments or other segments to build up the primary mirror. A systems’ design of all the elements constituting the assembly is provided, including tradeoffs, optimization, as well as mass and power budgets. The proposed solution scales with the size of the telescope and can be used to build primary mirrors as large as 20 m in diameter. The critical guidance, navigation, and control function is introduced, and related docking performances are presented. The results indicate that the in-space assembly of such large telescopes is feasible once these two key technologies are demonstrated in flight in the coming years.