SpooQySats: CubeSats to demonstrate quantum key distribution technologies

Satellite-based quantum key distribution (QKD) offers the potential to share highly secure encryption keys between optical ground stations all over the planet. SpooQySats is a programme for establishing the space worthiness of highly-miniaturized, polarization entangled, photon pair sources using CubeSat nanosatellites. The sources are being developed iteratively with an early version in orbit already and improved versions soon to be launched. Once fully developed, the photon pair sources can be deployed on more advanced satellites that are equipped with optical links. These can allow for very secure uplinks and downlinks and can be used to establish a global space-based quantum key distribution network. This would enable highly secure symmetric encryption keys to be shared between optical ground stations all over the planet. •A miniaturized photon pair source has been in orbit for over 335 days.•Future instruments for operational use will be three orders of magnitude brighter.•Orbiting quantum light sources will enable global quantum key distribution networks.