Satellite relayed tracking and data acquisition for the 1990's

The Tracking and Data Relay Satellite System (TDRSS) provides near-continuous tracking for low earth-orbiting spacecraft. Increases in data volume projected for the 90's will affect the configuration for data handling in one of two ways. One way involves an increase in the number of satellites in the TDRSS constellation. In connection with the second way, a new tracking and data acquisition satellite system will be developed. The new system will have greater capacity, increased reliability, and a more direct user-to-relay connectivity. The program for developing the ne satellite system of the 1990;s has been defined as Tracking and Data Acquisition System (TDAS). TDAS requirements are considered along with basic TDAS design parameters, TDAS spacecraft architectures, and TDAS constellation options. System and technology considerations are also discussed, taking into account user interface options, operational functions of the TDAS ground elements, and user communication technology.