|Launch vehicle.||Thor DM-21 Ablestar.|
|Launch date.||November 15, 1961, 22:26 UTC.|
|Launch site.||Cape Canaveral LC-17B.|
|Ceased operations.||August 12, 1962. Fatally damaged by the in the Starfish Prime high-altitude nuclear test of July 9, 1962, and shorted out that August.|
|Owner(s).||U.S. Navy (USN). The satellite system was also sponsored by the Navy and developed jointly by DARPA and the Johns Hopkins Applied Physics Laboratory.|
|Major contractor(s).||Johns Hopkins University Applied Physics Laboratory (APL).|
|Is it still in orbit.||N\A, but probably yes.|
|Launch mass.||86 kg.|
|Satellite type.||Navigation\communications satellite.|
|Links.||https://en.wikipedia.org/wiki/Transit_(satellite) and http://space.skyrocket.de/doc_sdat/transit-4.htm.|
The TRANSIT system, also known as NAVSAT or NNSS (for Navy Navigation Satellite 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.
Transit 4B and it's sister satellites had provided a continuous navigation satellite service from 1964, initially for Polaris submarines and later for civilian use as well. It carried an exsperimental SNAP 3 nuclear power source.
It was fatally damaged by the in the Starfish Prime high-altitude nuclear test of July 9, 1962, and shorted out on August 12, 1962.