Intelsat 509, previously named Intelsat V F-9, was a communications satellite operated by Intelsat. Launched in 1984, it was the ninth of fifteen Intelsat V satellites to be launched. The Intelsat V series was constructed by Ford Aerospace, based on the Intelsat-Vsatellite bus. Intelsat V F-9 was part of an advanced series of satellites designed to provide greater telecommunications capacity for Intelsat's global network. He also carried a Maritime Communications Services (MCS) package for Inmarsat. However, the launch vehicle failed to put the satellite into a useful orbit.
Payloads are separated by bullets ( · ), launches by pipes ( | ). Crewed flights are indicated in underline. Uncatalogued launch failures are listed in italics. Payloads deployed from other spacecraft are denoted in (brackets).