This project aligns with the Hub vision of expanding into free-space quantum communications at extra-terrestrial scales using satellites, and it is based on technology borne through Hub research and development. 3QN seeks to address the well-known distance limitations of QKD – the abundance of noise inside optical fibre in transmissions greater than a distance of about 150km makes QKD use impractical over large terrestrial scales. QKD through free space, on the other hand, can be less sensitive to distance. Satellites therefore provide the means for distributing keys across very large distances between end users spread across countries or continents, and facilitating global QKD networks. Crucial in all of these will be networks of Optical Ground Receivers required to receive and detect the photons carrying the key information. The 3QN project is focused on designing and building such affordable prototype modular optical QKD receivers that can be used to receive quantum keys from satellites using different QKD transmitters. Such devices would therefore not be limited to servicing any particular satellite but have a “plug and play” functionality instead, thus widening options for adoption and impact in the commercial world.