Intelsat IV-F1
Mission typeCommunications
COSPAR ID1975-042A[1]
SATCAT no.07815[2]
Mission duration7 years
Spacecraft properties
ManufacturerHughes Aircraft
Launch mass1,414 kilograms (3,117 lb)
BOL mass730 kilograms (1,610 lb)
Start of mission
Launch date22 May 1975, 22:04 (1975-05-22UTC22:04Z) UTC
RocketAtlas SLV-3D Centaur-D1A
Launch siteCape Canaveral LC-36B
Orbital parameters
Reference systemGeocentric
Semi-major axis42,449.0 kilometers (26,376.6 mi)
Perigee altitude36,032.3 kilometers (22,389.4 mi)
Apogee altitude36,124.6 kilometers (22,446.8 mi)
Period1,450.7 minutes
Epoch21 April 2017
Band12 IEEE C band (NATO G/H-band)
Bandwidth36 MHz
Intelsat IV
← Intelsat III F-7 (Intelsat III)

Intelsat IV F-1 was a geostationary communication satellite built by Hughes, it was owned by Intelsat. The satellite was based on the HS-312 platform and its estimated useful life was 7 years.


The Intelsat IV F-1 was part of the Intelsat IV series which consisted of eight communications satellites, launched from Cape Canaveral during the early 1970s, marked the fifth generation of geostationary communications satellites developed by the Hughes Aircraft Company since 1963 with the launch of Syncom II, the world's first synchronous satellite. The Syncom II was 15 cm high and 28 inches in diameter, weighing 78 pounds in orbit. In contrast, the Intelsat IVs weighed more than 1,300 lb (595 kg) into orbit and were more than 17 feet (5.2 meters) in diameter. All seven satellites exceeded their projected life expectancies and were withdrawn from active duty, the last of which, the Intelsat IV F-1 was retired in October 1987.

The satellite was equipped with 12 C-band transponders. It had 6,000 two-way relay phone calls or broadcast 12 concurrent color television programs or mixed combinations of communications traffic including data and fax.

The satellite had 12 channels of broadband communication. Each channel had a bandwidth of 40 MHz and provided about 500 communication circuits.


The satellite was successfully launched into space on May 22, 1975, by means of an Atlas SLV-3D Centaur-D vehicle from the Cape Canaveral Air Force Station in Florida, United States. It had a launch mass of 3,117 lb.[3]

See also


  1. ^ NASA Goddard Space Flight Center Intelsat IV F-1. NSSDC Master Catalog. Retrieved 19 April 2017.
  2. ^ [1]. Retrieved 02 Dec 2023.
  3. ^ Krebs, Gunter. Intelsat-4. Gunter's Space Page. Retrieved 2 Dec 2023.