Satellite‑based implementations are seen as the most near term and efficient route to achieving global coverage for a quantum communications network. The satellite network, in the long term, is envisioned to be made up of low‑Earth, medium, and geostationary constellations that enable global connectivity with a high reliance.

In its simplest scenario, a single low‑Earth orbit satellite can be used to service multiple ground stations. The satellite shares a quantum key (Key A) with one ground station, and then a separate key (Key B) with another. The satellite shares an XOR of both keys with one ground station, enabling that ground station to know the key of the other station. Now the two ground stations share a common key (Key A), they can share private messages secured by the key.

Within the Single‑Photon Group, we develop practical models to determine hardware requirements of the satellite and ground station, explore novel devices and techniques for next generation services, and develop quantum optical ground receiver technology for satellite missions.

We are an integral part of the National Quantum Communications Hub's in‑orbit demonstrator mission, where we lead the development, deployment, and operation of the quantum optical ground station. We are also involved with a number of industrial projects that are developing next generation quantum payload solutions for the satellite and ground station.