A condensed orbital history of Intelsat satellites

Intelsat, first established in 1964, has launched a total of 33 satellites between 1965 and 1983, including the Intelsat I, II, III, IV, IV-A and V series. Another 14 satellites, the Intelsat V-A and VI series, are under contract. Geostationary satellite service began in 1965 with the launch of Intelsat I over the Atlantic region. Launches of Intelsat II F-2 and Intelsat III F-3 over the Pacific and Indian Oceans followed in 1967 and 1969. Comsat managed the satellite system until Intelsat had established its own international staff in 1979. The Intelsat system's primary purupose is to provide transmission for public international communication traffic. As international communications increase, provision of spare satellites becomes important in the event of a failure in orbit. All Intelsat satellites operate on the 4 and 6 GHz frequency bands, while Intelsat V and subsequent satellites are also equipped to operate in the 11 and 14 GHz bands and, according to their designations, may be equipped to relay maritime traffic through Inmarsat. Despite several in-orbit incidents such as hydrogen peroxide propellant leakage, nickel-cadium battery deterioration, and uncommanded switching of electronic systems due to electrostatic discharges, it is concluded that the orbital history of Intelsat satellites has proved to be an outstanding success over the past 18 years. A comprehensive chart delineating the chronological evolution of the satellites is included.