Nanosatellite experiments to enable future space-based QKD missions

We present a programme for establishing the space worthiness of highly-miniaturised, polarisation-entangled, photon pair sources using CubeSat nanosatellites. Once demonstrated, the photon pair sources can be deployed on more advanced satellites that are equipped with optical links to establish a global space-based quantum key distribution network. In doing so, this work will also bring experimental tests of the overlap between quantum and relativistic regimes closer to realisation.