View source for Transit, Card No 04 (RaceIntoSpace 1971)

{{RISCard1971|{{BASEPAGENAMEE}}.jpg|04|Transit|13th April 1960
|The United States Navy instituted a navigation programme as long ago as 1958 to provide accurate, all-weather positional data for its ships around the world. 
Ballistic-missile submarines, in particular, need to know their position to a few hundred yards for launching their missiles.	

The first of a series of Transit satellites was launched from Cape Canaveral on	April 13th, 1960, into a 232 by 463 mile Earth orbit. 
The satellites continuously transmit their positions, so that any vessel receiving these signals can locate itself. 

Some commercial shipping also uses the system.}}