India set to join quantum satellite race for a hack-proof communication network

The satellite will play a key role in the larger quantum communications network under the National Quantum Mission (NQM).

Ajai Chowdhry, Co-founder of HCL and Chairman of the Mission Governing Board for the National Quantum Mission (NQM), told businessline, “Satellite-based communication will be required for securing country-wide or international communication. The Department of Space is planning to launch a quantum satellite in 2-3 years for quantum communications.” The NQM has set up four Section 8 companies across four verticals of quantum technologies that the mission aims to incubate: computing, communication, measurement, and sensing. Of these verticals, Chowdhry said the communications vertical seeks to make communication in India “completely safe” from quantum computers capable of breaking today’s encryption technologies. Satellite-based communication acts as a complementary medium to the larger quantum communication network, which primarily relies on optical fibre for photon transmission. While a satellite can transfer quantum data across large distances, transmission via optical fibre is limited to 100-250 km

According to Sunil Gupta, Co-founder of QNu Labs, one of the eight startups selected for NQM, “After 100-250 km, photons traveling through optical fibre experience energy loss. Hence, a trusted node box needs to be set up every 150 km, increasing costs and reducing practicality. Satellites, on the other hand, have a larger footprint. We plan to work on satellites over the next 6 to 12 months.”   

Recently, Jitendra Singh, Minister of State for Science and Technology and Earth Sciences, said in Parliament that the government will develop satellite-based secure quantum communications between two ground stations over a range of 2,000 km within India and internationally. However, Gupta said that even this alternative measure comes with its own set of challenges. “The problem with satellite-based communication is the LEO [low earth orbit] stationary satellite. The way a LEO satellite moves, you’ll have coverage only for 15–20 minutes a day. So, we need a constellation of 4–7 satellites. Either ISRO or a private player like Dhruva has to prioritise launching these satellites into orbit,” said Gupta. He also urged the government to speed up the overall NQM timeline in light of recent technologies like Google’s Willow computing chip.

 Nonetheless, Chowdhry remained confident about NQM’s progress, as the Union Cabinet has approved an outlay of ₹6,003.65 crore for the eight years of the Mission.