HELSINKI — China launched a new Tianlian data tracking and relay communications satellite Wednesday, adding to the country’s on-orbit infrastructure in the geostationary belt.
A Long March 3B lifted off at 11:55 a.m. Eastern (1555 UTC) March 26 from the Xichang Satellite Launch Center, southwest China. The China Aerospace Science and Technology Corporation (CASC) announced the success of the launch around an hour after liftoff, revealing the payload to be the Tianlian-2 (04) data tracking and relay communications satellite.
While the launch was expected due to airspace closure notices, the payload only became apparent with CASC’s post-launch statement. The satellite is now in geosynchronous transfer orbit (GTO) and will maneuver to take up a position along the geostationary belt, around 35,786 kilometers above the equator.
Tianlian-2 (04) is part of China’s second-generation geostationary orbit (GEO) data relay satellite system. It is designed to provide data relay and telemetry, tracking, and command (TT&C) services for crewed spacecraft including the Tiangong space station and Shenzhou spacecraft, as well as for medium- and low Earth orbit satellites and launches.
Tianlian satellites perform a similar role as the U.S. Tracking and Data Relay Satellite System (TDRSS). The Tianlian system, with satellites placed at various points around GEO to provide near constant coverage, recently supported a seven-hour-long extravehicular activity outside the Tiangong station.
The new satellite, compared with Tianlian-2 (03) launched in July 2022, features several technical upgrades, including transmission capacity and response speed. The improvements aim to meet growing domestic needs for data and TT&C while enhancing the autonomy and security of China’s second-gen relay system, according to CASC.
China launched its first Tianlian satellite—Tianlian-1 (01)—in 2008. It, and the subsequent Tianlian-1 (02) and (03) satellites, are now in graveyard orbits above the geostationary belt, according to U.S. Space Force space tracking data. Tianlian-1 (04) and (05), together with the new generation Tianlian-2 (01), (02) and (03) satellites, remain active in GEO.
Like earlier satellites in the series, Tianlian-2 (04) was developed by the China Academy of Space Technology (CAST), a major spacecraft-making institute under CASC, the country’s state-owned main space contractor. CALT, a major rocket maker under CASC, provided the Long March 3B; a hypergolic propellant rocket which has long been China’s workhorse for geosynchronous launches.
Wednesday’s mission was China’s 15th orbital launch of 2025. It follows a pair of Ceres-1 solid propellant rocket launches from commercial launch company Galactic Energy. The first, on March 17, sent eight satellites into orbit, including six commercial meteorological satellites, from Jiuquan Satellite Launch Center, northwest China. The second, just four days later from the same launch area at Jiuquan, sent another six commercial meteorological satellites into orbit for the same Yunyao-1 constellation.
Galactic Energy is preparing to debut the larger Ceres-2 solid rocket and the kerosene-liquid oxygen propellant Pallas-1 rocket later this year.
CASC has not yet published an overview of its plans for 2025. However, the country, with expanded spaceport capabilities, megaconstellation projects underway, and new launchers expected to debut, could be targeting around 100 or more launches across the year. This would eclipse the national record 68 launches last year. An increase in commercial launch activity is expected, with a number of new, medium-lift and potentially reusable rockets targeting debut flights.
Major missions will include the Shenzhou-20 and 21 human spaceflight missions to Tiangong. The Tianwen-2 near-Earth asteroid sample return mission is expected to launch from Xichang on a Long March 3B rocket around May.
