Intelsat III F-1

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.

Intelsat III F-1

Mission type	Communications
Operator	Intelsat
COSPAR ID	INT3F-1
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 ← Intelsat II F-4 (Intelsat II) Intelsat III F-2 →

Design

Launch of Intelsat III F-1.

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]

Launch

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]

It was to go in operation above the Atlantic Ocean in time to relay broadcasts of the next month's Olympics in Mexico City.^[4][5][6]

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.^[7] At 108 seconds after launch the rocket was destroyed by range safety.^[8]

See also

• Spaceflight portal

• 1968 in spaceflight