Intelsat III F-3
Mission typeCommunications
OperatorIntelsat
COSPAR ID1969-011A
SATCAT no.03674
Mission duration5 years
Spacecraft properties
Spacecraft typeIntelsat III
ManufacturerTRW
Launch mass293 kg (646 lb)
BOL mass151 kg (333 lb)
Power183 watts
Start of mission
Launch dateFebruary 6, 1969, 00:39:00 (1969-02-06UTC00:39Z) UTC[1]
RocketDelta M
Launch siteCape Canaveral LC-17A
ContractorNASA[2]
End of mission
DisposalDecommissioned
Deactivatedc.December 14, 1979 (1979-12-15)[3]
Orbital parameters
Reference systemGeocentric
RegimeGeosynchronous
Now Graveyard
Longitude174° east (1969)
63° east (1969-c.1975)
Perigee39,921 km (24,806 mi)[4]
Apogee41,534 km (25,808 mi)[4]
Inclination18.33 degrees[4]
Period1695.49 minutes[4]
EpochJanuary 23, 2015, 15:01:00 UTC[4]
Intelsat III
 

Intelsat III F-3 was a geostationary communications satellite operated by Intelsat. Launched in 1969 it was intended for operations over the Pacific Ocean; however, it spent most of its service life over the Indian Ocean at a longitude of 63 degrees east.[5]

The third of eight Intelsat III satellites to be launched, Intelsat III F-3 was built by TRW. It was a 293-kilogram (646 lb) spacecraft, with its mass reducing to 151 kilograms (333 lb) by entry into service as it burned propellant to reach its final orbit. The satellite carried an SVM-2 apogee motor for propulsion and was equipped with two transponders powered by body-mounted solar cells generating 183 watts of power.[6] It was designed for 5 years of service life.[7]

The launch of Intelsat III F-3 made use of a Delta M rocket flying from Launch Complex 17A at the Cape Canaveral Air Force Station. The launch, which was conducted by NASA, took place at 00:39:00 UTC on February 6, 1969, with the spacecraft entering a geosynchronous transfer orbit.[1] Shortly after launch, Intelsat III F-3 fired its apogee motor to achieve geostationary orbit.

Intended to be operated over the Pacific Ocean at a longitude of 174° east, Intelsat III F-3 was moved to the less important Indian Ocean slot at 63° east after only three months in orbit due to concerns regarding its reliability.[8] The satellite was only regarded as partially operable; however, it remained in service until April 1979, before being decommissioned in December of that year.[3][8]

At the end of its service life, Intelsat III F-3 was raised into a higher orbit to reduce the probability of it colliding with an operational spacecraft. As of February 3, 2014 it remains in orbit, with a perigee of 39,935 kilometers (24,814 mi), an apogee of 41,521 kilometers (25,800 mi), inclination of 18.63 degrees and an orbital period of 28.25 hours.[4]

References

  1. ^ a b McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved February 9, 2014.
  2. ^ "INTELSAT 3 F-3". National Space Science Data Center. Retrieved February 9, 2014.
  3. ^ a b McDowell, Jonathan. "Geostationary Satellite Log". Jonathan's Space Page. Archived from the original on September 9, 2016. Retrieved February 9, 2014.
  4. ^ a b c d e f "INTELSAT 3-F3 Satellite details 1969-011A NORAD 03674". N2YO. January 23, 2015. Retrieved January 25, 2015.
  5. ^ "Intelsat 3 Quicklook". Mission and Spacecraft Library. NASA Jet Propulsion Laboratory. Retrieved February 9, 2014.
  6. ^ Wade, Mark. "Intelsat 3". Encyclopedia Astronautica. Retrieved February 9, 2014.
  7. ^ Krebs, Gunter. "Intelsat-3". Gunter's Space Page. Retrieved February 9, 2014.
  8. ^ a b "Chronology of Intelsat Development and Operations, 1969-1978". NASA Historical Data Book. NASA History Office. Retrieved February 9, 2014.