The Transit system was the first satellite navigation system to be used operationally. The system was primarily used by the U.S. Navy to provide accurate location information to its Polaris ballistic missile submarines, and it was also used as a navigation system by the Navy's surface ships, as well as for hydrographic survey and geodetic surveying. April 13, 1960 at 12:02 UTC · Launch Successful Thor DM-21 Ablestar — United States Air Force, to Polar Orbit Space Launch Complex 17B, Cape Canaveral SFS, FL, USA The world's 61st orbital launch attempt, and 7th of 1960. Data: Launch Library 2, The Space Devs. Image via The Space Devs.