Tracking and data relay satellite system (TDRSS) - A worldwide view from space

The development, performance levels, and operational use of the TDRSS satellite system are outlined. The TDRSS spacecraft were conceived in the mid-1960s by NASA as a means of using GEO-positioned satellites to eliminate existing ground stations. The main ground terminal becomes Goddard Space Flight Center, through which users other than the Shuttle can also gain access. The TDRSS functions as a relay vehicle, with very little on-board processing except for status reports inserted into the data stream. Use of the TDRSS system by nonNASA agencies currently costs $110/min for forwards, return, and tracking, $24/min for forward service alone, and $8/min for return service only. The spacecraft can store data on board and dump it to the ground station during the limited hours of operation.