INSAT-1A
INSAT-1A was an Indian communications satellite which formed part of the Indian National Satellite System. Launched in 1982, it was operated in geostationary orbit at a longitude of 74° east. Following a series of failures, the satellite was abandoned in September 1983, less than 18 months into a seven-year mission.

Built by Ford Aerospace and operated by the Indian National Satellite System, INSAT-1A was based upon a custom satellite bus developed for the INSAT-1 series. It had a mass at launch of , and was expected to operate for 7 years. The spacecraft carried 12 C and 3 S band transponders, powered by a single solar array.

NASA was contracted to launch INSAT-1A using a Delta 3910 rocket with a PAM-D upper stage. The launch occurred at 06:47 UTC on 10 April 1982, from Launch Complex 17A at Cape Canaveral Air Force Station. The satellite was successfully inserted into geosynchronous transfer orbit, from which it raised itself into geostationary orbit. It received the International Designator 1982-031A and Satellite Catalog Number 13129.

Following launch, INSAT-1A had some initial problems deploying its antennas, solar array and stabilisation boom. The C-band antenna could not be deployed for twelve days, and the solar array failed to extend fully, preventing the spacecraft generating enough power to conduct weather observation. The satellite's S-band transponders subsequently overheated and failed. The stabilisation boom failed to deploy altogether.

Early in the satellite's mission a fault in a valve in its attitude control system was detected which caused the spacecraft to expend propellant at a greater rate than expected. On 4 September 1983 the satellite's primary earth-tracking sensor was temporarily deactivated to protect the system while the sun passed through its field of view. Owing to the failure of the stabilisation boom, the backup sensor was not oriented in the correct direction, instead being oriented towards the moon, which overloaded it and shut down the sensor. The satellite exhausted its remaining propellant supply trying to regain earth-lock, and was abandoned on 6 September. Due to the sudden nature of its failure, INSAT-1A was not removed from geosynchronous orbit. As of 10 November 2013 it is in an orbit with a perigee of , an apogee of , inclination of 14.59 degrees and an orbital period of 23.93 hours.
Q668
India
LOC
Q149918
communications satellite
Concept
Q1642195
Indian National Satellite System
MEDIA
Q192316
geostationary orbit
Concept
Q4353824
Ford Aerospace
ORG
Q1642195
Indian National Satellite System
MEDIA
Q372881
satellite bus
Concept
Q1642195
INSAT
MEDIA
Q2344775
C
Concept
Q2018880
S band
Concept
Q1897785
solar array
Concept
Q23548
NASA
Concept
Q49520
Delta 3910
MISC
Q1424161
PAM-D
MISC
Q1034324
Launch Complex 17A
LOC
Q334465
Cape Canaveral Air Force Station
LOC
Q1138649
geosynchronous transfer orbit
Concept
Q192316
geostationary orbit
Concept
Q54228
International Designator
ORG
Q913832
Satellite Catalog Number
UNK
Q83481
perigee
Concept
Q83481
apogee
Concept
Q4112212
inclination
Concept
Q37640
orbital period
Concept
Q13115907
INSAT-1A
Concept
Q13115907
INSAT-1A
Concept
Q13115907
INSAT-1A
Concept
Q13115907
INSAT-1A
Concept
Q13115907
INSAT-1A
Concept
1982-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1982
DATE
1983-09-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
September 1983
DATE
3910-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
3910
DATE
1982-04-10T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
10 April 1982
DATE
1982-01-01T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
1982
DATE
1983-09-04T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
4 September 1983
DATE
2013-11-10T00:00:00Z^^http://www.w3.org/2001/XMLSchema#dateTime
10 November 2013
DATE
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NUMBER
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74
NUMBER
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-031
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NUMBER
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NUMBER
+14.59^^http://www.w3.org/2001/XMLSchema#decimal
14.59
NUMBER
+23.93^^http://www.w3.org/2001/XMLSchema#decimal
23.93
NUMBER
country
instance of
part of
manufacturer
part of
part of
space launch vehicle
start point
UTC date of spacecraft launch
part of