Intelsat III F-1

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Intelsat III F-1
Mission type Communications
Operator Intelsat
Mission duration 5 years planned
Failed to orbit
Spacecraft properties
Spacecraft type Intelsat III
Manufacturer TRW
Launch mass 293 kilograms (646 lb)
Power 183 watts
Start of mission
Launch date September 19, 1968, 00:09:00 (1968-09-19UTC00:09Z) UTC[1]
Rocket Delta M
Launch site Cape Canaveral LC-17A
Contractor NASA
Orbital parameters
Reference system Geocentric
Regime Geosynchronous
Epoch Planned

Intelsat III F-1 was a communications satellite intended to be operated by Intelsat. Launched towards geostationary orbit in 1968 it failed to achieve orbit.


The first of eight Intelsat III satellites to be launched, Intelsat III F-1 was built by TRW. It was a 293-kilogram (646 lb) spacecraft equipped with two transponders to be powered by body-mounted solar cells generating 183 watts of power.[2] It had a design life of five years and carried an SVM-2 apogee motor for propulsion..[3]


Intelsat III F-1 was launched on the maiden flight of the Delta M rocket, flying from Launch Complex 17A at the Cape Canaveral Air Force Station. The launch took place at 00:09:00 UTC on September 19, 1968, with the spacecraft bound for a geosynchronous transfer orbit.[1]

Twenty seconds after liftoff a fault became apparent in the gyroscope used to monitor the rate at which the rocket pitched over. Control of the rocket was subsequently lost, with it beginning to disintegrate around 102 seconds into the flight.[4] At 108 seconds after launch the rocket was destroyed by range safety.[5]

See also[edit]


  1. ^ a b McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved February 9, 2014. 
  2. ^ Wade, Mark. "Intelsat 3". Encyclopedia Astronautica. Retrieved February 9, 2014. 
  3. ^ Krebs, Gunter. "Intelsat-3". Gunter's Space Page. Retrieved February 9, 2014. 
  4. ^ Kyle, Ed. "Long Tank Thor-Delta". Space Launch Report. Retrieved February 9, 2014. 
  5. ^ Kyle, Ed. "Thor-Based Space Launch History". Space Launch Report. Retrieved February 9, 2014.