Xairos UK Limited, Inmarsat, and Heriot-Watt University will advance the development of satellite-based Quantum Time Transfer (QTT). This project will advance the development of QTT, a new secure optical two-way time transfer technology capable of highly secure picosecond level precision between ground-based clocks and clocks onboard satellites. QTT utilises individual photon pairs entangled in time and frequency, as well as in polarisation, to securely distribute time and frequency information. The project will address three separate, but inter-related tasks, necessary to develop the first on orbit demonstration of quantum secured time transfer at the picosecond level:
•Develop of a High-Fidelity QTT Simulation Model
•Develop a Space-Qualifiable QTT Entangled Photon Source 
•Develop an implementation roadmap through a Commercialisation Study