TDRS-3
Encyclopedia
TDRS-3 , known before launch as TDRS-C, is an American
communications satellite
which is operated by NASA
as part of the Tracking and Data Relay Satellite System
. It was constructed by TRW
, and is based on a custom satellite bus
which was used for all seven first generation TDRS satellites.
The TDRS-C satellite was launched aboard during the STS-26R
mission in 1988; the first Shuttle flight since the Challenger accident
which had resulted in the loss of the previous TDRS satellite, TDRS-B
. Discovery launched from Launch Complex 39B
at the Kennedy Space Center
at 15:37:00 GMT on 29 September 1988. TDRS-C was deployed from Discovery around six hours after launch, and was raised to geostationary orbit
by means of an Inertial Upper Stage
.
The two-stage solid-propellent Inertial Upper Stage made two burns. The first stage burn occurred shortly after deployment from Discovery, and placed the satellite into a geosynchronous transfer orbit. At 04:30 on 30 September it reached apogee, and the second stage fired, placing TDRS-C into geosynchronous orbit. At this point it received its operational designation. Although the TDRS-2 designation had not been assigned, TDRS-C was given the designation TDRS-3 as NASA did not want to reuse the designation which had been intended for the STS-51-L
payload. It was briefly placed at a longitude 151° West of the Greenwich Meridian, before being moved to 171° West before the end of 1988, from where it provided communications services to spacecraft in Earth orbit, including Space Shuttle
s. In 1990, it was relocated to 174° West, and again in 1991 to 62° West. In 1994 it returned to 171° West. In June 1995, it was moved to 85° East, from where it was used primarily for communications with spacecraft such as the Compton Gamma Ray Observatory
and the Hubble Space Telescope
. It is now primarily used as a backup satellite. Over time, its orbital inclination
has increased due to natural forces, to approximately 12 degrees.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
communications satellite
Communications satellite
A communications satellite is an artificial satellite stationed in space for the purpose of telecommunications...
which is operated by NASA
NASA
The National Aeronautics and Space Administration is the agency of the United States government that is responsible for the nation's civilian space program and for aeronautics and aerospace research...
as part of the Tracking and Data Relay Satellite System
Tracking and Data Relay Satellite System
The Tracking and Data Relay Satellite System is a network of American communications satellites and ground stations used by NASA for space communications. The system was designed to replace an existing network of ground stations that had supported all of NASA's manned flight missions...
. It was constructed by TRW
TRW
TRW Inc. was an American corporation involved in a variety of businesses, mainly aerospace, automotive, and credit reporting. It was a pioneer in multiple fields including electronic components, integrated circuits, computers, software and systems engineering. TRW built many spacecraft,...
, and is based on a custom satellite bus
Satellite bus
A satellite bus or spacecraft bus is the general model on which multiple-production satellite spacecraft are often based. The bus is the infrastructure of a spacecraft, usually providing locations for the payload .They are most commonly used for geosynchronous satellites, particularly...
which was used for all seven first generation TDRS satellites.
The TDRS-C satellite was launched aboard during the STS-26R
STS-26
STS-26 was the 26th NASA Space Shuttle mission and the seventh flight of the Discovery orbiter. The mission launched from Kennedy Space Center, Florida, on 29 September 1988, and landed four days later on 3 October. STS-26 was declared the "Return to Flight" mission, being the first mission after...
mission in 1988; the first Shuttle flight since the Challenger accident
Space Shuttle Challenger disaster
The Space Shuttle Challenger disaster occurred on January 28, 1986, when Space Shuttle Challenger broke apart 73 seconds into its flight, leading to the deaths of its seven crew members. The spacecraft disintegrated over the Atlantic Ocean, off the coast of central Florida at 11:38 am EST...
which had resulted in the loss of the previous TDRS satellite, TDRS-B
TDRS-B
TDRS-B was an American communications satellite, which was to have formed part of the Tracking and Data Relay Satellite System. It was destroyed when the disintegrated 73 seconds after launch....
. Discovery launched from Launch Complex 39B
Kennedy Space Center Launch Complex 39
Launch Complex 39 is a rocket launch site at the John F. Kennedy Space Center on Merritt Island in Florida, USA. The site and its collection of facilities were originally built for the Apollo program, and later modified to support Space Shuttle operations. NASA began modifying LC-39 in 2007 to...
at the Kennedy Space Center
Kennedy Space Center
The John F. Kennedy Space Center is the NASA installation that has been the launch site for every United States human space flight since 1968. Although such flights are currently on hiatus, KSC continues to manage and operate unmanned rocket launch facilities for America's civilian space program...
at 15:37:00 GMT on 29 September 1988. TDRS-C was deployed from Discovery around six hours after launch, and was raised to geostationary orbit
Geostationary orbit
A geostationary orbit is a geosynchronous orbit directly above the Earth's equator , with a period equal to the Earth's rotational period and an orbital eccentricity of approximately zero. An object in a geostationary orbit appears motionless, at a fixed position in the sky, to ground observers...
by means of an Inertial Upper Stage
Inertial Upper Stage
The Inertial Upper Stage , originally known as the Interim Upper Stage, is a two-stage solid-fueled booster rocket developed by the U.S...
.
The two-stage solid-propellent Inertial Upper Stage made two burns. The first stage burn occurred shortly after deployment from Discovery, and placed the satellite into a geosynchronous transfer orbit. At 04:30 on 30 September it reached apogee, and the second stage fired, placing TDRS-C into geosynchronous orbit. At this point it received its operational designation. Although the TDRS-2 designation had not been assigned, TDRS-C was given the designation TDRS-3 as NASA did not want to reuse the designation which had been intended for the STS-51-L
STS-51-L
STS-51-L was the twenty-fifth flight of the American Space Shuttle program, which marked the first time an ordinary civilian, schoolteacher Christa McAuliffe, had flown aboard the Space Shuttle. The mission used Space Shuttle Challenger, which lifted off from the Launch Complex 39-B on 28 January...
payload. It was briefly placed at a longitude 151° West of the Greenwich Meridian, before being moved to 171° West before the end of 1988, from where it provided communications services to spacecraft in Earth orbit, including Space Shuttle
Space Shuttle
The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...
s. In 1990, it was relocated to 174° West, and again in 1991 to 62° West. In 1994 it returned to 171° West. In June 1995, it was moved to 85° East, from where it was used primarily for communications with spacecraft such as the Compton Gamma Ray Observatory
Compton Gamma Ray Observatory
The Compton Gamma Ray Observatory was a space observatory detecting light from 20 KeV to 30 GeV in Earth orbit from 1991 to 2000. It featured four main telescopes in one spacecraft covering x-rays and gamma-rays, including various specialized sub-instruments and detectors...
and the Hubble Space Telescope
Hubble Space Telescope
The Hubble Space Telescope is a space telescope that was carried into orbit by a Space Shuttle in 1990 and remains in operation. A 2.4 meter aperture telescope in low Earth orbit, Hubble's four main instruments observe in the near ultraviolet, visible, and near infrared...
. It is now primarily used as a backup satellite. Over time, its orbital inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
has increased due to natural forces, to approximately 12 degrees.