The TL 1 (Tian Lian 1) satellite is a geostationary relay satellite based on the DFH-3 Bus (three-axis-stabilized
telecommunications satellite platform). TL 1 will be used to support real-time communications between orbiting satellites
and ground control stations. This system will replace the current network of ground-based space tracking and telemetry
stations and space tracking ships.
TL 1 represents the experimental first generation of this new network. Later satellites will be of more advanced
Tianlian 1-03 is joining its two predecessors to realize global network operation after in-orbit validation and system coordination
procedures are carried out. "The first data relay satellite, the Tianlian I-01, was launched in April 2008, and the second was
launched in July 2011. The third satellite is expected to improve the network's coverage in providing measurement and control
services for China′s manned spacecraft as well as the planned construction of future space labs and space stations, according to
the center. The network will also offer data relay services for the country's medium- and low-Earth orbits as well as measurement
and control support for spacecraft launches. The two-satellite network had previously played a key role in assisting in two space
docking missions; an automated one between the Tiangong-1 lab module and the Shenzhou-8 spacecraft in late 2011, and a manual
docking between Tiangong-1 and Shenzhou-9 in June.
China′s third tracking and data relay satellite was launched on Jul 25, 2012.
Tianlian yihao 03 xing (Tianlian-1 Satellite 03) flew to a 199 x 42513 km x 18.1 deg geostationary transfer orbit on a CZ-3C rocket.