The twin-stage solid-propellant Inertial Upper Stage made two burns. The first stage burn occurred shortly after deployment from Discovery, and placed the satellite into a geostationary transfer orbit (GTO). At 03:30 UTC on 14 March 1989, it reached apogee, and the second stage fired, placing TDRS-D into geostationary orbit.[5] At this point, it received its operational designation, TDRS-4. It was placed at a longitude 41.0° West of the Greenwich Meridian,[6][7] from where it provided communications services to spacecraft in Earth orbit, including the Space Shuttle and International Space Station. In 2005, it was relocated to 46.0° West.[6]
Retirement
TDRS-4 completed its planned mission in December 2011, and was subsequently removed to a graveyard orbit 350 kilometres (220 mi) above GEO orbit belt, per International Telecommunication Union (ITU) and United Nations (UN) recommendations.[8] In May 2012, NASA reported that the orbit-raising manoeuvre had been completed successfully, and the spacecraft had been retired.[9]
^Johnson, Nicholas (5 December 2011). "Space debris issues". audio file, @1:03:05-1:05:10. The Space Show. Archived from the original on 27 January 2012. Retrieved 8 December 2011.
Launches are separated by dots ( • ), payloads by commas ( , ), multiple names for the same satellite by slashes ( / ). Crewed flights are underlined. Launch failures are marked with the † sign. Payloads deployed from other spacecraft are (enclosed in parentheses).