Intelsat III F-8

Mission type	Communications
Operator	Intelsat
COSPAR ID	1970-055A
SATCAT no.	04478
Mission duration	5 years (planned) Launch failure
Spacecraft properties
Manufacturer	TRW
Launch mass	293 kilograms (646 lb)
BOL mass	151 kilograms (333 lb)
Power	183 W
Start of mission
Launch date	July 23, 1970, 00:16:03 (1970-07-23UTC00:16:03Z) UTC[1]
Rocket	Delta M
Launch site	Cape Canaveral LC-17A
Orbital parameters
Reference system	Geocentric[2]
Regime	Geostationary[2]
Eccentricity	0.24386[2]
Perigee altitude	19,400 kilometers (12,100 mi)[2]
Apogee altitude	36,030 kilometers (22,390 mi)[2]
Inclination	13.3°[2]
Period	1,043.0 minutes[2]
Epoch	July 23, 1970[2]
Intelsat III ← Intelsat III F-7 Intelsat IV F-1 (Intelsat IV) →

Intelsat III F-8 was a communications satellite owned by Intelsat. The satellite had an estimated useful life of 5 years.

Design

The last of eight Intelsat III satellites to be launched, Intelsat III F-8 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.^[3] It had a design life of five years and carried an SVM-2 apogee motor for propulsion.^[4]

Launch

Intelsat III F-8 was launched on a Delta M rocket, flying from Launch Complex 17A at the Cape Canaveral Air Force Station. The launch took place on July 23, 1970, with the spacecraft bound for a geosynchronous transfer orbit.^[1]

The Intelsat III F-8 was lost due to a malfunction during the apogee motor firing. Communications stopped 14.5 seconds into the planned 27 second apogee motor burn.