The orbiting Tiangong-2 space lab has transmitted quantum-encryption keys to four ground stations, researchers reported on 18 August. The same network of ground stations is also able to receive quantum keys from the orbiting Micius satellite, which is in a much higher orbit, using the space station as a repeater. It comes just after the late July launch of Jinan 1, China’s second quantum-encrypting satellite, by the University of Science and Technology of China. USTC told the Xinhua News Agency that the new satellite is one-sixth the mass of its 2016 predecessor.

“The launch is significant,” says physicist Paul Kwiat of the University of Illinois in Urbana-Champaign, because it means the team are starting to build, not just plan, a quantum network. USTC researchers did not reply to IEEE Spectrum’s request for comments.