Space debris

"Space Junk" redirects here. For other uses, see Space Junk (disambiguation).
"Cosmic debris" redirects here. For the Frank Zappa song, see Cosmik Debris.

Infographic showing the space debris situation in different kinds of orbits around Earth
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Space debris (also known as space junk, space pollution,[1] space waste, space trash, space garbage, or cosmic debris[2]) are defunct human-made objects in space – principally in Earth orbit – which no longer serve a useful function. These include derelict spacecraft (nonfunctional spacecraft and abandoned launch vehicle stages), mission-related debris, and particularly numerous in-Earth orbit, fragmentation debris from the breakup of derelict rocket bodies and spacecraft. In addition to derelict human-made objects left in orbit, space debris includes fragments from disintegration, erosion, or collisions; solidified liquids expelled from spacecraft; unburned particles from solid rocket motors; and even paint flecks. Space debris represents a risk to spacecraft.[3]

Space debris is typically a negative externality. It creates an external cost on others from the initial action to launch or use a spacecraft in near-Earth orbit, a cost that is typically not taken into account nor fully accounted for[4][5] by the launcher or payload owner.[6][1][7]

Several spacecraft, both crewed and un-crewed, have been damaged or destroyed by space debris. The measurement, mitigation, and potential removal of debris is conducted by some participants in the space industry.[8]

As of November 2022, the US Space Surveillance Network reported 25,857 artificial objects in orbit above the Earth,[9] including 5,465 operational satellites.[10] However, these are just the objects large enough to be tracked and in an orbit that makes tracking possible. Satellite debris that is in a Molniya orbit, such as the Kosmos Oko series, might be too high above the Northern Hemisphere to be tracked.[11] As of January 2019, more than 128 million pieces of debris smaller than 1 cm (0.4 in), about 900,000 pieces of debris 1–10 cm, and around 34,000 of pieces larger than 10 cm (3.9 in) were estimated to be in orbit around the Earth.[8] When the smallest objects of artificial space debris (paint flecks, solid rocket exhaust particles, etc.) are grouped with micrometeoroids, they are together sometimes referred to by space agencies as MMOD (Micrometeoroid and Orbital Debris).

Collisions with debris have become a hazard to spacecraft. The smallest objects cause damage akin to sandblasting, especially to solar panels and optics like telescopes or star trackers that cannot easily be protected by a ballistic shield.[12]

Below 2,000 km (1,200 mi), pieces of debris are denser than meteoroids. Most are dust from solid rocket motors, surface erosion debris like paint flakes, and frozen coolant from Soviet nuclear-powered satellites.[13][14][15] For comparison, the International Space Station (ISS) orbits in the 300–400 kilometres (190–250 mi) range, while the two most recent large debris events, the 2007 Chinese antisatellite weapon test and the 2009 satellite collision, occurred at 800 to 900 kilometres (500 to 560 mi) altitude.[16] The ISS has Whipple shielding to resist damage from small MMOD. However, known debris with a collision chance over 1/10,000 are avoided by maneuvering the station.

  1. ^ a b "'We've left junk everywhere': why space pollution could be humanity's next big problem". The Guardian. 26 March 2016. Archived from the original on 8 November 2019. Retrieved 28 December 2019.
  2. ^ Powell, Jonathan (2017). Cosmic Debris. Astronomers' Universe. Bibcode:2017cdwi.book.....P. doi:10.1007/978-3-319-51016-3. ISBN 978-3-319-51015-6.
  3. ^ "Guide to Space Debris". spaceacademy.net.au. Archived from the original on 26 August 2018. Retrieved 13 August 2018.
  4. ^ Coase, Ronald (October 1960). "The Problem of Social Cost" (PDF). Journal of Law and Economics (PDF). 3. The University of Chicago Press: 1–44. doi:10.1086/466560. JSTOR 724810. S2CID 222331226. Archived (PDF) from the original on 17 June 2012. Retrieved 13 December 2019.
  5. ^ Heyne, Paul; Boettke, Peter J.; Prychitko, David L. (2014). The Economic Way of Thinking (13th ed.). Pearson. pp. 227–228. ISBN 978-0-13-299129-2.
  6. ^ Muñoz-Patchen, Chelsea (2019). "Regulating the Space Commons: Treating Space Debris as Abandoned Property in Violation of the Outer Space Treaty". Chicago Journal of International Law. University of Chicago Law School. Archived from the original on 13 December 2019. Retrieved 13 December 2019.
  7. ^ Werner, Debra (30 March 2018). "Preventing space pollution". Aerospace America. Retrieved 21 January 2023.
  8. ^ a b "Space debris by the numbers". www.esa.int. Retrieved 18 April 2024.
  9. ^ Cite error: The named reference ODQN-201911 was invoked but never defined (see the help page).
  10. ^ Cite error: The named reference ucs20191216 was invoked but never defined (see the help page).
  11. ^ Clark, David (2006). The Elgar Companion to Development Studies. Edward Elgar Publishing. p. 668. ISBN 978-1-84376-475-5.
  12. ^ "The Threat of Orbital Debris and Protecting NASA Space Assets from Satellite Collisions" (PDF). Space Reference. 2009. Archived (PDF) from the original on 23 December 2015. Retrieved 18 December 2012.
  13. ^ Wiedemann, C. (2 April 2009). "Size distribution of NaK droplets for MASTER-2009". Proceedings of the 5th European Conference on Space Debris. 672: 17. Bibcode:2009ESASP.672E..17W.
  14. ^ A. Rossi et al, "Effects of the RORSAT NaK Drops on the Long Term Evolution of the Space Debris Population", University of Pisa, 1997.
  15. ^ Wiedemann, C.; Oswald, M.; Stabroth, S.; Klinkrad, H.; Vörsmann, P. (2005). "Size distribution of NaK droplets released during RORSAT reactor core ejection". Advances in Space Research. 35 (7): 1290–1295. Bibcode:2005AdSpR..35.1290W. doi:10.1016/j.asr.2005.05.056.
  16. ^ The Threat of Orbital Debris and Protecting NASA Space Assets from Satellite Collisions (PDF), Space Reference, 2009, archived (PDF) from the original on 23 December 2015, retrieved 18 December 2012.