China has launched two new satellites for its homegrown rival to the US’s GPS system, known as the Beidou Navigation Satellite System. The successful launch marks another solid step in building Beidou into a navigation system with global coverage.

The satellites were launched Saturday from the Xichang Satellite Launch Center in southern China. They are the 18th and 19th to join the satellite navigation system. The two satellites reached their target orbits three and a half hours after the launch.

They will be used to test a new type of navigation signaling and inter-satellite links, and also provide navigation services.

China launched the first Beidou satellite in 2000. The system began providing services to civilian users in China and surrounding areas in the Asia-Pacific in December 2012.