A system operated by the USA, under the name NAVSTAR originally developed for military purposes.

1978-1985 Test phase using 11 Block I satellites altogether (Figure). The last one of these satellites is decommissioned at the end of 1995.

1989-1990 Deployment of the successor generation (Block II, nine satellites) developed for full operation of the system. The last (and the only) one of them is yet in operation in May 2005.

1990-1997 Deployment of 19 advanced (Block IIA) satellites. The GPS system reaches full operational capability in 1995, following placement in orbit of the 24th satellite.

1997-2005 Deployment of the next generation (Block IIR) of at least 16 satellites. The most recent launch was planned for May 20, two further launches will follow in July and autumn 2005, respectively.

Starting in 2005 (planned), the successor generation Block IIF will be deployed (Figure at the startpage of "Satellite Navigation").