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.