Issue 120

China Launches (Another) Relay Satellite

27 Apr: China launched a Long March-3B from Xichang carrying the TianLian-2 05 (TL-2 05) (63662) relay satellite to Geosynchronous Transfer Orbit. TL-2 05 is the fifth satellite of China's second-generation data relay satellite system and joins TianLian-1 04 & 05 and TianLian-2 01, 02, 03 and 04 to provide global data…

27 Apr: China launched a Long March-3B from Xichang carrying the TianLian-2 05 (TL-2 05) (63662) relay satellite to Geosynchronous Transfer Orbit. TL-2 05 is the fifth satellite of China’s second-generation data relay satellite system and joins TianLian-1 04 & 05 and TianLian-2 01, 02, 03 and 04 to provide global data relay and transmission services. The relay satellite network allows near real time communications between China Space Station (and other LEO satellites) and their mission control centers. As of 4 May the satellite remained unlocated. Launch Video.

– The addition of Tianlian-2 05 brings the total to 7 operational Tianlian relay satellites. This is China’s second Tianlian launch in 2025. There were zero TL launches in 2023 or 2024.

– The Tianlian satellites are similar to NASA’s Tracking and Data Relay Satellite network and the European Space Agency’s European Data Relay Satellite network. Overall, the Tianlian network consists of 2 first generation and 5 second generation satellites.

– The first generation of TianLian (“sky chain”) satellites were built around the DFH-3 satellite bus and were launched between 25 Apr 2008, and 6 Jul 2021 using Long March 3C rockets from Xichang.

– The second generation of Tianlian satellites are built around the DFH-4 satellite bus and have switched to the more powerful Long March 3B also launching from Xichang.

– The second generation of the satellites introduced multi-targeting ability and improved data transmission rates into the overall network.

– TL-2 uses K-band frequencies (TL-1 satellites used 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 14 astronauts are currently living and working. See video on China’s relay satellite capabilities.

https://www.youtube.com/watch?v=m_fQK6GpLG8