Optical inter-satellite link terminals for next generation satellite constellations

The aerospace network connectivity market is currently experiencing a renewed period of intense activity in space, driven by numerous companies planning constellations of thousands of low Earth orbit satellites. These constellations - globe-spanning networks of interconnected satellites - promise to enhance Earth observation, facilitate the Internet of Things, and bring connectivity to the estimated half of the world's population still without internet. The consequent demand for data bandwidth that will follow from these developments can only be delivered through the implementation of optical inter-satellite links, routing user information on-demand and with minimum delay. The economic feasibility of these endeavors is dependent on the size, weight, and power requirements (SWaP) of the laser terminals that will provide the backbone connectivity of these constellations. Given that several optical terminals will be required per satellite, they need to not only establish gigabit data links over thousands of kilometers but also possess minimal SWaP and mostly be design-engineered for serial production. This paper discusses the requirements for optical terminals derived from constellation modeling. We update on the qualification status of the inter-satellite link terminal program, and introduce our roadmap for large scale serial production.