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TDRS-C was the second successful launch of the Tracking and Data Relay Satellite series. TDRS-C was used in combination with other TDRS spacecraft and a ground communications system to form the Tracking and Data Relay Satellite System (TDRSS).

The objective of the TDRSS program is to provide and maintain improved tracking and data acquisition services to spacecraft in low-Earth orbit. In order to fulfill this objective, TDRSS requires at least two fully operational TDRS in orbit with one or more additional spacecraft serving as system spares.

Each TDRS is a three-axis, momentum-biased satellite. The bus section of the spacecraft is hexagonal with an approximate diameter of 3 m. Power is provided by two opposing, three-section solar array panels, 4.0 x 3.8 m in dimension, at the end of 3.25 m booms. Perpendicular to the solar arrays are the two 4.9 m diameter, K- and S-band, single-access (SA) antennae. With the solar panels and SA antennae deployed, TDRS measures 17.3 x 14.2 m.

TDRS is comprised of three functional modules: payload, spacecraft, and antenna. The payload module consists of two single-access compartments, the multiple access antenna platform, and a main payload module. The main payload module has six panels which form an integral part of the main bus structure and house the principle elements of the TDRS payload. The spacecraft module contains the thermal control, electrical power, attitude control, propulsion, and tracking, telemetry, and command systems. The antenna module consists of the two SA dish antennae, the 2.0 m K-band Space-to-Ground Link (SGL) antenna, and, on the bus of the spacecraft, the 30 helical element, multiple access (MA) antenna array, a C-band antenna, and an S-band omnidirectional SGL antenna.

Alternate Names

  • 19548
  • TDRS 3
  • Tracking and Data Relay Satellite 3

Facts in Brief

Launch Date: 1988-09-29
Launch Vehicle: Shuttle
Launch Site: Cape Canaveral, United States
Mass: 2224.9 kg
Nominal Power: 1700 W

Funding Agency

  • NASA-Office of Tracking and Data Acquisition (United States)


  • Communications

Additional Information

Questions and comments about this spacecraft can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Mr. George Q. ClarkProject ManagerNASA Goddard Space Flight Center

Related Information/Data at NSSDCA

STS 26

Other Sources of TDRS Information/Data

TDRS program

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