PARIS — A Chinese Long March 3C rocket on July 25 successfully placed the Tianlian-03 data-relay satellite into geostationary transfer orbit, where it will join two other data-relay spacecraft, the China Great Wall Industry Corp. announced July 26.

The launch, from the Xichang Satellite Launch Center in China’s Sichuan Province, was the 11th Long March liftoff for the Long March series this year and the 53rd flight of the Long March 3A family, which is used for most geostationary-orbit launches.

The two previous data-relay satellites, Tianlian-01 and Tianlian-03, are operated at 77 degrees and 176.8 degrees east in geostationary orbit, respectively, following their launches in 2008 and 2011. It was not immediately known where Tianlian-03 will operate.

The data-relay spacecraft are used to relay Earth observation data from low-orbiting satellites to the Earth, and to provide communications links for China’s astronaut program, much as the U.S. TDRS and Russian Luch satellites do.

Peter B. de Selding was the Paris bureau chief for SpaceNews.