Before there was GPS there was TRANSIT.
American missile firing submarine fleet requiring up-to-the-minute and vital navigational precision of which the solution was an orbiting satellite called TRANSIT.
"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"
Transmissions from near-earth orbiting satellites allowing submariners to determine their position with an unprecedented degree of accuracy.
Data from the satellite transmissions processed by a unique and task tailored ship-board computer.
"Since no computer small enough to fit through a submarine's hatch existed (in 1958), a new computer was designed, named the AN/UYK-1. It was built with rounded corners to fit through the hatch and was about five feet tall [one and one-half meters] and sealed to be waterproof."
A TRW advertisement for the AN/UYK-1. Called the TRW-130 in the commercial model. Cost circa early 1960's listed as $73,340 USD complete with software. Computer sans radio receiver. Calculations regarding position with print-out.
TRANSIT and the AN/UYK-1 at that exact moment in time state-of-the-art but by modern standards primitive in the extreme. How times have changed!