Spacecraft Tracking and Data Acquisition Network
The Spacecraft Tracking and Data Acquisition Network was known by the abbreviation STADAN. NASA built it in the early 1960s. It gave ground controllers only about fifteen minutes of contact with a spacecraft during each ninety minute trip around the Earth. What made those fifteen minutes possible, and where on the planet did the listening happen? And what came before STADAN, the network that made a new one necessary?
Before STADAN existed, a network called Minitrack tracked the flights of Sputnik, Vanguard, Explorer, and other early space missions between 1957 and 1962. STADAN picked up where Minitrack left off, designed to provide communication that lasted longer and stayed available more reliably. That growing web of ground stations still needed a nerve center to keep every dish pointed the right way.
The Network Operations Control Center, known as the NOCC, handled real-time operational control and scheduling from Goddard Space Flight Center in Greenbelt, Maryland. Parabolic dish antennas paired with telephone switching equipment carried the signals between spacecraft and that center.
Stations reporting to the NOCC ringed the globe. In the United States, dishes stood at Fort Myers in Florida, Rosman in North Carolina, East Grand Forks in Minnesota, and Fairbanks in Alaska. California held three: the Goldstone Deep Space Communications Complex, Barstow, and Brown Field near Chula Vista. Bermuda's Cooper's Island and Newfoundland's Shoe Cove, in Canada, extended coverage north and east. Santiago and Antofagasta in Chile, Quito in Ecuador, and Lima in Peru covered South America. Johannesburg in South Africa, Tananarive in Madagascar, and Ascension Island in the South Atlantic Ocean carried the chain across Africa. Winkfield in England and Crete in Greece anchored Europe, while a station in Pakistan reached into Asia. Australia hosted three: Carnarvon, the Orroral Valley Tracking Station near Canberra, and the Cooby Creek Tracking Station near Toowoomba in Queensland. Not every spacecraft passing overhead needed the same amount of attention, and that difference would soon reshape the network.
By May 1971, NASA merged STADAN with the Manned Space Flight Network to create the Spaceflight Tracking and Data Network. The new combined system took the abbreviation STDN. The contact each ground pass had provided was enough for satellites that operated without a crew aboard, but astronauts needed far more of it. That merger folded STADAN's ground stations into a larger operation, though it would not be the network's final transformation.
By the early 1980s, most STADAN stations had closed. A new system, the Tracking and Data Relay Satellite System, took over most of the tracking work for satellites in low Earth orbit. Engineers called the replacement TDRS.
The Deep Space Network took over crewed missions higher than 10,000 miles above Earth, including the Apollo flights. Deep space probes remained the Deep Space Network's main assignment throughout. Where STADAN once listened for satellites passing close overhead, the Deep Space Network's dishes still turn toward probes searching far beyond Earth.
Common questions
What was the Spacecraft Tracking and Data Acquisition Network?
The Spacecraft Tracking and Data Acquisition Network, abbreviated STADAN, was a NASA system built in the early 1960s for long duration, highly available space to ground communication. It gave ground controllers about fifteen minutes of contact with a spacecraft during each ninety minute orbit.
When was the Spacecraft Tracking and Data Acquisition Network established?
NASA established STADAN in the early 1960s as a follow on to the earlier Minitrack network, which had tracked Sputnik, Vanguard, Explorer, and other early missions between 1957 and 1962.
Where were the Spacecraft Tracking and Data Acquisition Network's ground stations located?
STADAN stations were spread across the globe, including sites in Chile, Bermuda, South Africa, Australia, the United States, Canada, Ecuador, Peru, Madagascar, England, Ascension Island, Pakistan, and Greece. The Network Operations Control Center that ran the system sat at Goddard Space Flight Center in Greenbelt, Maryland.
Why did the Spacecraft Tracking and Data Acquisition Network merge with the Manned Space Flight Network?
STADAN's roughly fifteen minute contact windows per orbit worked for uncrewed satellites but were not enough for crewed missions, which needed far more data collection time. In May 1971, NASA merged STADAN with the Manned Space Flight Network to form the Spaceflight Tracking and Data Network, or STDN.
What replaced the Spacecraft Tracking and Data Acquisition Network's stations?
Most STADAN stations were phased out in the early 1980s as the Tracking and Data Relay Satellite System, or TDRS, took over tracking of satellites in low Earth orbit. The Deep Space Network handled crewed spacecraft farther than 10,000 miles from Earth, such as the Apollo missions, alongside its main job of collecting data from deep space probes.
How much contact time did the Spacecraft Tracking and Data Acquisition Network provide per orbit?
STADAN provided about fifteen minutes of space to ground communication during each ninety minute orbit period. That was enough for uncrewed spacecraft but insufficient for crewed missions, which needed considerably more contact time.