Graveyard orbit

A graveyard orbit is an orbit where spacecraft are intentionally placed at the end of their operational life. It is a measure performed in order to lower the probability of collisions with operational spacecraft and of the generation of additional space debris. It is used when the delta-v required to perform a de-orbit maneuver would be too high. De-orbiting a geostationary satellite would require a delta-v of about 1,500 m/s while re-orbiting it to a graveyard orbit would require about 11 m/s.

For satellites in a geostationary orbit the graveyard orbit would be few hundred kilometers above the opertational orbit. The transfer to graveyard orbit above geostationary orbit however requires the same amount of fuel that a satellite needs for approximately 3 months of stationkeeping. It also requires a reliable attitude control during the transfer maneuver. While most satellite operators try to perform such a maneuver at the end of the operational life only one third succeed in doing so.