Graveyard orbit

Not to be confused with Spacecraft cemetery.

Short description: Spacecraft end-of-life orbit

Comparison of geostationary, GPS, GLONASS, Galileo, Compass (MEO), International Space Station, Hubble Space Telescope, Iridium constellation and graveyard orbits, with the Radiation|Radiation

belt]]s and the Earth to scale.[lower-alpha 1] The Moon's orbit is around 9 times as large as geostationary orbit.[lower-alpha 2] (In the SVG file, hover over an orbit or its label to highlight it; click to load its article.)]]

An example of a graveyard orbit – Earth fixed frame
Earth * Spaceway-1 * Spaceway-2 * Spaceway-3

A graveyard orbit, also called a junk orbit or disposal orbit, is an orbit that lies away from common operational orbits. One significant graveyard orbit is a supersynchronous orbit well beyond geosynchronous orbit. Some satellites are moved into such orbits at the end of their operational life to reduce the probability of colliding with operational spacecraft and generating space debris.

## Contents

* 1 Overview
* 2 Disposal orbit
* 3 See also
* 4 Notes
* 5 References

## Overview

A graveyard orbit is used when the change in velocity required to perform a de-orbit maneuver is too large. De-orbiting a geostationary satellite requires a delta-v of about 1,500 metres per second (4,900 ft/s), whereas re-orbiting it to a graveyard orbit only requires about 11 metres per second (36 ft/s).[1]

For satellites in geostationary orbit and geosynchronous orbits, the graveyard orbit is a few hundred kilometers beyond the operational orbit. The transfer to a graveyard orbit beyond geostationary orbit requires the same amount of fuel as a satellite needs for about three months of stationkeeping. It also requires a reliable attitude control during the transfer maneuver. While most satellite operators plan to perform such a maneuver at the end of their satellites' operational lives, through 2005 only about one-third succeeded.[2] Given the economic value of the positions at geosynchronous altitude, unless premature spacecraft failure precludes it, satellites are moved to a graveyard orbit prior to decommissioning.[3][4]

According to the Inter-Agency Space Debris Coordination Committee (IADC) the minimum recommended perigee altitude ΔH beyond the geostationary orbit is[5]

ΔH=235 km+CRA[m2]m[kg]⋅1000 km

where

CR is the satellite's solar radiation pressure coefficient, whose value is between 1 (for absorption) and 2 (for specular reflection),
A is its aspect area,
m is its mass.

This formula includes 200 kilometres (120 mi) for the GEO-protected zone to also permit orbit maneuvers in GEO without interference with the graveyard orbit. Another 35 kilometres (22 mi) of 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 Federal Communications Commission (FCC) requires all geostationary satellites launched after March 18, 2002, to commit to moving to a graveyard orbit at the end of their operational lives.[6] U.S. government regulations require a boost, ΔH, of about 300 km (186 mi).[7] In 2023 DISH received the first-ever fine by the FCC for failing to de-orbit its EchoStar VII satellite according to the terms of its license.[8]

A spacecraft moved to a graveyard orbit will typically be passivated.

Uncontrolled objects in a near geostationary [Earth] orbit (GEO) exhibit a 53-year cycle of orbital inclination[9] due to the interaction of the Earth's tilt with the lunar orbit. The orbital inclination varies ± 7.4°, at up to 0.8°pa.[9]: 3

## Disposal orbit

While the standard geosynchronous satellite graveyard orbit results in an expected orbital lifetime of millions of years, the increasing number of satellites, the launch of microsatellites, and the FCC approval of large megaconstellations of thousands of satellites for launch by 2022 necessitated new approaches for deorbiting to assure earlier removal of the objects once they have reached end-of-life. Contrary to GEO graveyard orbits requiring three months' worth of fuel (delta-V of 11 m/s) to reach, large satellite networks in LEO require orbits that passively decay into the Earth's atmosphere. For example, both OneWeb and SpaceX have committed to the FCC regulatory authorities that decommissioned satellites will decay to a lower orbit - a disposal orbit - where the satellite orbital altitude would decay due to atmospheric drag and then naturally reenter the atmosphere and burn up within one year of end-of-life.[10]

## See also

* List of orbits
* SNAP-10A – nuclear reactor satellite, remaining in a 700-nautical-mile (1,300 km; 810 mi) sub-synchronous Earth orbit for an expected 4,000 years
* Spacecraft cemetery, in the Pacific Ocean

## Notes

1. ↑ Orbital periods and speeds are calculated using the relations 4π2R3 = T2GM and V2R = GM, where R = radius of orbit in metres, T = orbital period in seconds, V = orbital speed in m/s, G = gravitational constant ≈ 6.673×10−11 Nm2/kg2, M = mass of Earth ≈ 5.98×1024 kg.
2. ↑ Approximately 8.6 times (in radius and length) when the moon is nearest (363 104 km ÷ 42 164 km) to 9.6 times when the moon is farthest (405 696 km ÷ 42 164 km).

## References

1. ↑ "Method for re-orbiting a dual-mode propulsion geostationary spacecraft – Patent # 5651515 – PatentGenius". http://www.patentgenius.com/patent/5651515.html.
2. ↑ "ESA – Space debris mitigation: the case for a code of conduct". http://www.esa.int/Enabling_Support/Operations/Space_debris_mitigation_the_case_for_a_code_of_conduct.
3. ↑ Jehn, R.; Agapov, V.; Hernández, C. (20 April 2005). "End-of-Life Disposal of Geostationary Satellites". Proceedings of the 4th European Conference on Space Debris (ESA SP-587) (ESA/ESOC) 587: 373. Bibcode: 2005ESASP.587..373J. https://adsabs.harvard.edu/full/2005ESASP.587..373J. Retrieved November 6, 2022.
4. ↑ Johnson, Nicholas (2011-12-05). "Broadcast 1666 (Special Edition) – Topic: Space debris issues". in Livingston, David. The Space Show. 1:03:05–1:06:20. http://www.thespaceshow.com/show/05-dec-2011/broadcast-1666-special-edition.
5. ↑ "Report of the IADC Activities on Space Debris Mitigation Measures". Guideline 5.3.1: Post mission disposal for geosynchronous region. http://www.iadc-online.org/Documents/IADC-UNCOPUOS-final.pdf.
6. ↑ "FCC Enters Orbital Debris Debate". http://www.space.com/spacenews/businessmonday_040628.html.
7. ↑ "US Government Orbital Debris Standard Practices". http://orbitaldebris.jsc.nasa.gov/library/USG_OD_Standard_Practices.pdf.
8. ↑ Shepardson, David (2 October 2023). "DISH gets first-ever space debris fine over EchoStar-7". Reuters. https://www.reuters.com/technology/space/dish-gets-first-ever-space-debris-fine-over-echostar-7-2023-10-02/.
9. ↑ 9.0 9.1 Anderson, Paul (2015). "Operational Considerations of GEO Debris Synchronization Dynamics". 66th International Astronautical Congress. Jerusalem, Israel. IAC-15,A6,7,3,x27478. http://hanspeterschaub.info/Papers/Anderson2015c.pdf.
10. ↑ Brodkin, Jon (4 October 2017). "SpaceX and OneWeb broadband satellites raise fears about space debris". Ars Technica. https://arstechnica.com/information-technology/2017/10/spacex-and-oneweb-broadband-satellites-raise-fears-about-space-debris/.

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Gravitational orbits

Types|

| General|

* Box
* Capture
* Circular
* Elliptical / Highly elliptical
* Escape
* Horseshoe
* Hyperbolic trajectory
* Inclined / Non-inclined
* Lagrangian point
* Osculating
* Parabolic trajectory
* Parking
* Prograde / Retrograde
* Synchronous
* semi
* sub
* Transfer orbit

|

Geocentric|

* Geosynchronous
* Geostationary
* Geostationary transfer
* Graveyard
* High Earth
* Low Earth
* Medium Earth
* Molniya
* Near-equatorial
* Orbit of the Moon
* Polar
* Sun-synchronous
* Tundra

About other points|

* Mars
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* Heliosynchronous

Parameters|

* Shape
* Size

* e Eccentricity
* a Semi-major axis
* b Semi-minor axis
* Q, q Apsides

|

Orientation|

* i Inclination
* Ω Longitude of the ascending node
* ω Argument of periapsis
* ϖ Longitude of the periapsis

Position|

* M Mean anomaly
* ν, θ, f True anomaly
* E Eccentric anomaly
* L Mean longitude
* l True longitude

Variation|

* T Orbital period
* n Mean motion
* v Orbital speed
* t0 Epoch

Maneuvers|

* Bi-elliptic transfer
* Collision avoidance (spacecraft)
* Delta-v
* Delta-v budget
* Gravity assist
* Gravity turn
* Hohmann transfer
* Inclination change
* Low energy transfer
* Oberth effect
* Phasing
* Rocket equation
* Rendezvous
* Transposition, docking, and extraction

Orbital mechanics|

* Celestial coordinate system
* Characteristic energy
* Escape velocity
* Ephemeris
* Equatorial coordinate system
* Ground track
* Hill sphere
* Interplanetary Transport Network
* Kepler's laws of planetary motion
* Lagrangian point
* n-body problem
* Orbit equation
* Orbital state vectors
* Perturbation
* Retrograde motion
* Specific orbital energy
* Specific relative angular momentum
* Two-line elements

* List of orbits

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