Designing a laser communications payload integral to a nano-satellite, capable of fine pointing, is a difficult task. Integrating this with a quantum key distribution payload for inter-satellite secure communication adds significant complexity, as does ground based communication with the moving objects in low Earth orbit. The advantages of low path length, secure, global communication make this an opportunity not to be missed.
We report on developments of such a system. Beginning with a satellite demonstrator with a Pointing, Acquisition-and Tracking system that involves fine precision star-tracker, plasma and aerodynamic force interactions for steering, and an inter-satellite laser link demonstration on orbit using LED beacon for acquisition, and laser for communications link closure. Combining design studies for a nano-satellite quantum payload for transferring entangled photon-pairs between the satellites at long-range in Low Earth Orbit, and incorporating ground to space and space to ground laser communications, are described in the context of quantum optical ground station efforts within Australia.
|