Minitrack

The Minitrack Network, was the first U.S. satellite tracking network to become operational, in 1957. It was used to track the flights of Sputnik, Vanguard, Explorer, and other early space efforts. Minitrack was the progenitor of Spacecraft Tracking and Data Acquisition Network (STADAN) and the Manned Space Flight Network (MSFN).

Read more about Minitrack:  Origins, Development, Technical Problems, Minitrack and Sputnik, Midlife: 1958-1962, Transformation Into STADAN, Bibliography