The Spacecraft Tracking and Data (Acquisition) Network (STADAN or STDN) was established by NASA in the early 1960s to satisfy the requirement for long-duration, highly available space-to-ground communications. The network was the "follow-on" to the earlier Minitrack, which tracked the flights of Sputnik, Vanguard, Explorer, and other early space efforts (1957–1962). Real-time operational control and scheduling of the network was provided by the Network Operations Control Center (NOCC) at the Goddard Space Flight Center (GSFC) in Greenbelt, Maryland.[1]
Consisting of parabolic dish antennas and telephone switching equipment deployed around the world, the STADAN provided space-to-ground communications for approximately 15 minutes of a 90-minute orbit period. This limited contact period sufficed for uncrewed spacecraft, but crewed spacecraft require a much higher data collection time. In May 1971 STADAN was consolidated with the Manned Space Flight Network (MSFN) to form the Spaceflight Tracking and Data Network (STDN).[2]