China spent around US$100 million on a single satellite to prove that quantum-secured communication could work from orbit. That satellite, Micius, was launched in August 2016 from Jiuquan on a Long March 2D rocket, and it re-entered the atmosphere on 25 January 2026, about nine and a half years later.
Micius was the core of the Quantum Experiments at Space Scale project, run by the Chinese Academy of Sciences with ground stations across China. The University of Vienna and the Austrian Academy of Sciences operated its European receiving stations. The project grew out of a competition, then a partnership, between the Austrian physicist Anton Zeilinger and his former doctoral student Jianwei Pan. Zeilinger could not get funding for a European satellite, so he joined the Chinese effort. Beijing paid for Pan’s version quickly.
What the satellite did
The idea is simple to state. Its main instrument made pairs of entangled photons and sent one of each pair to the ground. Because any attempt to eavesdrop disturbs the entangled state in a way that can be detected, the pairs can carry a secret key between two parties. Fiber cables and the atmosphere both scatter photons, which limits how far this works on the ground. From orbit there is less scattering, so the distances can be far greater.
The first experiment linked the Xinjiang Astronomical Observatory near Ürümqi with Xinglong Observatory near Beijing, a distance of about 2,500 kilometers. The team tested Bell’s inequality at 1,200 kilometers, farther than any experiment before it, and teleported a photon state between the satellite and Shiquanhe Observatory in Tibet. In 2021, full quantum state teleportation was shown over 1,200 kilometers on the ground, using entanglement the satellite had distributed.
Micius then opened a quantum key channel between China and the Institute for Quantum Optics and Quantum Information in Vienna, a ground distance of 7,500 kilometers. It carried what was described as the first intercontinental secure quantum video call, in 2016. The key distribution work won the American Association for the Advancement of Science’s Newcomb Cleveland Prize in 2018.
Limits and defense interest
The satellite itself had limited communication capacity. It needed line of sight, and it could only operate when it was not in sunlight.
Pan told Reuters the project had “enormous prospects” in defense. The satellite was to provide secure communications between Beijing and Ürümqi. The US Department of Defense believed China was aiming to counter enemy use of space technology, and the New York Times noted that quantum technology was a focus of China’s thirteenth five-year plan. The Wall Street Journal said the launch put China ahead of rivals on the way to “hack-proof communications.” Several outlets pointed to Edward Snowden’s leaks as an impetus, and Popular Science called it “a satellite for the post-Snowden age.”
What came next
A global network of further Micius-type satellites was planned for 2030. In March 2025, researchers reported Jinan-1, billed as the first quantum microsatellite. It produced keys in real time with compact ground stations in China and South Africa, and it enabled encrypted communication between Beijing and Stellenbosch over about 12,900 kilometers. The European Space Agency intends to launch its own quantum key distribution satellite, Eagle-1, as part of the European Quantum Communication Infrastructure.
