Issue 37

China Launches TianLian-2 (02) Relay Satellite

China launched TianLian-2 (02), its seventh tracking and data relay satellite, on 13 December 2021.

13 Dec 2021: China launched the Tianlian (TL) 2 tracking and data relay satellite from the Xichang Satellite Launch Center. Its mission is to enable communications between spacecraft and is the second TL-2 placed in orbit (the first launched in Mar 2019). The launch vehicle was a Chang Zheng (Long March) 3B/E. Video.

– The Tianlian satellites provide data relay for Chinese crewed vehicles and space assets. This includes communication with the Chinese Space Station and other LEO satellites.

– The TL-2 has a 15 year lifespan and uses the DFH-4 bus vs TL-1 satellites and the DFH-3 bus. TL-2(02) is the 7th relay satellite (5x TL-1 and 2x TL-2). All are listed as active.

– TL-2 also uses K-band frequencies (TL-1 satellites used the S-band) to enable 1.2 Gbps data transfer rates between the Chinese Space Station and ground control stations. The satellites make real-time communications including video possible between the ground and the Tianhe space station module, where three Shenzhou 13 astronauts are currently living and working.

– TL-2(02) was the 401st Long March launch. Prior to this launch, the most recent TL launch was the 5th TL-1 satellite in Jul 2021.

– In 2012, the Tianlian constellation achieved global coverage with the launch of the third spacecraft, TL-1(03), on 25 Jul 2012.

TL-2(02) remains in GTO as of 18 December. It passed through apogee on 15 Dec near 160° east longitude, suggesting it is aimed for either 167° E or 177° E. These locations correlate to the current locations of TL-1(02) (166.14°E) and TL-1(04) (176.68°E). TL-2(01) is also located near another relay satellite, TL-1(01).

Likely Locations for TL-2(02).