Information about Disposal Orbit

A graveyard orbit, also called a supersynchronous orbit, junk orbit or disposal orbit, is an orbit significantly above synchronous 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 and geosynchronous orbits, the graveyard orbit would be few hundred kilometers above the operational orbit. The transfer to graveyard orbit above geostationary orbit however requires the same amount of fuel that a satellite needs for approximately three 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.

According to the Inter-Agency Space Debris Coordination Committee (IADC) [1] the minimum perigee altitude above the geostationary orbit should be:

where is the solar radiation pressure coefficient (typically between 1.2 and 1.5) and is the aspect area [m²] to mass [kg] ratio of the satellite. This formula includes about 200 km for the GEO protected zone to also permit orbit maneuvers in GEO without interference with the graveyard orbit. Another 35 kilometers tolerance must be allowed for the effects of gravitational perturbations (primarily solar and lunar). The remaining part of the equation considers the effects of the solar radiation pressure, which depends on the physical parameters of the satellite.

In order to obtain a license to provide telecommunications services in the United States, the FCC requires all geostationary satellites launched after March 18, 2002, to commit to moving to a graveyard orbit at the end of their operational life.^[1] U.S. government regulations require a boost, , of ~300 km.^[2]

References

See also

• List of orbits

•  • [ e] Orbits
Orbit types	Box orbit • Circular orbit • Ecliptic orbit • Elliptic orbit • Highly Elliptical Orbit • Graveyard orbit • Hyperbolic trajectory • Inclined orbit • Osculating orbit • Parabolic trajectory • Capture orbit • Escape orbit • Semi-synchronous orbit • Subsynchronous orbit • Synchronous orbit • Parking orbit
Earth-centered orbits	Geosynchronous orbit • Geostationary orbit • Sun-synchronous orbit • Low Earth orbit • Medium Earth Orbit • Molniya orbit • Near equatorial orbit • Orbit of the Moon • Polar orbit • Tundra orbit
Other orbits	Areosynchronous orbit • Areostationary orbit • Halo orbit • Lissajous orbit • Lunar orbit • Heliocentric orbit • Heliosynchronous orbit
Orbital elements	Inclination () • Longitude of the ascending node () • Eccentricity () • Argument of periapsis () • Semi-major axis () • Mean anomaly at epoch ()
Other orbital parameters	True anomaly () • Semi-minor axis () • Linear eccentricity () • Eccentric anomaly () • Mean longitude () • True longitude () • Orbital period ()
Orbital maneuvers	Bi-elliptic transfer • Geostationary transfer orbit • Gravitational slingshot • Hohmann transfer orbit • Orbital inclination change • Orbit phasing • Space rendezvous
Other orbital mechanics topics	Apsis • Celestial coordinate system • Delta-v budget • Epoch • Ephemeris • Equatorial coordinate system • Gravity turn • Ground track • Interplanetary Transport Network • Kepler's laws of planetary motion • Lagrangian point • List of orbits • n-body problem • Orbit equation • Orbital state vectors • Perturbation • Retrograde and direct motion • Specific orbital energy • Specific relative angular momentum • The Oberth effect