Quantum Experiments using Satellite Technology

Quantum Experiments using Satellite Technology, often shortened to QuEST, is an Indian research project begun in 2017 by the Raman Research Institute and described as the country's first project on satellite based long-distance quantum communication. As reported so far it has been a ground demonstration rather than a flight: in February 2021 it showed quantum communication over 50 metres, and on 19 March 2021 over 300 metres in line of sight at the Space Applications Centre, in coordination with the Indian Space Research Organisation, the Indian Institute of Science and the Tata Institute of Fundamental Research. The system uses an indigenous NavIC receiver for time synchronization, a gimbal mechanism instead of a large-aperture telescope for optical alignment, and an entangled photon source using the BBM92 protocol. It has shared secure text and images and supported two-way video conferencing between the Space Applications Centre and the Physical Research Laboratory.