It was the first Tracking and Data Relay Satellite, of second generation, to be launched.Due to a malfunction of the multiple-access phased array antenna the spacecraft did not provide the expected level of performance for eighteen of the communications services that it was to provide.The same problem was found and corrected on the TDRS-9 and TDRS-10 satellites prior to their launches.Following its launch, it raised itself into geostationary orbit by means of its onboard R-4D apogee motor, and was positioned at 150.0° West for on-orbit testing.After testing was complete, it was moved to 171.0° East from where it provides communications services to spacecraft in Earth orbit, including the Space Shuttle and International Space Station.