The Evolution of the Spaceflight Tracking and Data Network (STDN)

Abstract

On July 29, 1955, President Eishenhower announced that the United States would launch an "Earth Circling" satellite as a part of the U.S. participation in the International Geophysical Year (IGY). Project Vanguard was this country's first efforts in space. It was the Soviet Union, however, that inaugurated the space age by launching Sputniks 1 and 2. Then, after the failure of the first Vanguard launch test, the President authorized the use of a military missile. The Army's successful launch of Explorer I was followed by the successful launch of the Vanguard I satellite. Thus, with two Soviet and two American satellites in six months, the space age was born. The Minitrack Network, the first worldwide satellite tracking capability (1957-1962), evolved into the Satellite Tracking and Data Acquisition Network (1960-1966). The Mercury Network, which became operational in 1961, was the foundation for the Manned Space Flight Network which was also to support the following Gemini and Apollo missions. The NASA Communications Network (NASCOM) began to take shape in the early 1960s. All of these functions began playing together (1965) and were consolidated in the early 1970s as the Space Tracking and Data Network (STDN). The STDN has supported both the manned and scientific missions during the 1970s. The concept of spacecraft tracking support from a satellite system in synchronous orbit began in 1966. Feasibility studies for this Tracking and Data Relay Satellite System (TDRSS) were completed in 1971, the definition phase was completed in 1973, and the contractor-owned government leased TDRSS system is expected to be operational in 1983. This paper will discuss the historical and technical aspects of these satellite tracking systems that have supported our space program from its beginning in 1955, and will take a brief look at the future.