The Intelsat VI series was constructed by Hughes Aircraft, based on the HS-389 satellite bus.

[2] Intelsat 603 was launched at 11:52:31 UTC on 14 March 1990, atop a Commercial Titan III carrier rocket, flight number CT-2, with an Orbus-21S upper stage.

The Orbus-21S failed to separate from the Titan's second stage, and as a result it was unable to fire, leaving Intelsat 603 in low Earth orbit.

During its maiden flight, STS-49, in 1992 Space Shuttle Endeavour rendezvoused with and captured Intelsat 603, and astronauts attached a new Orbus-21S to the satellite.

Finally from May 2010 it operated at 11.5 degrees east until it was removed from geostationary orbit in January 2013.