China launches twin satellites into space China's Long March-3B rocket, carrying the Beidou-M3 and Beidou-M4 satellites, has blasted off from the Xichang Satellite Launch Centre in southwest China's Sichuan Province. The pair of navigation satellites are part of the constellation for the country's independently-built global navigation system. They are the 12th and the 13th elements of China's Beidou navigation constellation, which began providing partial positioning and navigation services in December. The Beidou system was approved in 2004 and is capable of providing continuous, real-time passive 3D geo-spatial positioning and speed measurement. The country's long-term goal is to develop a global navigation satellite network similar to the GPS by 2020, eventually forming a constellation of 35 satellites.