At 1518 GMT 0n 5 January 2017, a Long March 3B/G2 rocket took off from the Xichang launch site in China. Aboard was a mysterious satellite called TJS-2. The satellite was placed into a geosynchronous transfer orbit (GTO) on its way to a final operational position in the geostationary arc. The spacecraft is thought to be in excess of 5000 kg and carries a large unfurlable antenna, and may be connected with China’s early warning effort, either as a relay satellite or as a detector.