Colliding Satellites: Consequences and Implications

The February 10, 2009 collision between the Iridium 33 and Cosmos 2251 satellites at an altitude of 470 miles significantly increased space debris in an already crowded region of low Earth orbit (LEO). The collision, occurring at speeds over 22,000 mph, created a debris cloud that spreads globally, threatening other satellites. Because atmospheric drag is minimal at this altitude, a large fraction of the debris will remain in orbit for decades, with roughly one-quarter of large debris expected to persist after 30 years. The document notes that the 700 to 1,000 km altitude band is already 'supercritical,' meaning collisions create debris faster than atmospheric drag removes it, potentially leading to a chain reaction. While international debris mitigation guidelines exist, the author argues they should be made mandatory and enforced, and suggests the development of space traffic management systems to preserve the long-term use of space.

• The collision between Iridium 33 and Cosmos 2251 on February 10, 2009, occurred at an altitude of 470 miles (770 km) and at a speed exceeding 22,000 mph (10 km/s), creating a debris cloud that threatens other satellites in the region.
• The debris from the collision will spread to form a shell around the Earth, becoming a global problem for all satellites passing through that specific altitude.
• Due to low atmospheric drag at the collision altitude, much of the debris will persist for decades; approximately 25% of large debris is estimated to remain in orbit after 30 years.
• The region between 700 and 1,000 km is the most likely place for collisions due to high satellite and debris density, and it is already considered 'supercritical,' meaning debris is created by collisions faster than it is removed by atmospheric drag.
• The author estimates that a collision between a piece of debris larger than 1 cm and an active satellite in near-Earth orbit will occur on average every 2 to 3 years over the next decade.
• The U.S. Space Surveillance Network can only reliably track debris larger than 5 to 10 cm, meaning the majority of dangerous debris (those larger than 1 cm) from the collision will not be observed from the ground.
• Existing international debris mitigation guidelines, while helpful in the mid-1990s, were undermined by a single event—the 2007 breakup of the Chinese Feng Yun-1C satellite—and should now be made mandatory with enforcement measures.

APA

Wright, D. (2009). Colliding Satellites: Consequences and Implications. Union of Concerned Scientists. https://www.ucs.org/sites/default/files/2019-10/SatelliteCollision-2-12-09.pdf

Chicago

Wright, David. Colliding Satellites: Consequences and Implications. Union of Concerned Scientists, 2009. https://www.ucs.org/sites/default/files/2019-10/SatelliteCollision-2-12-09.pdf.

Wikipedia

{{cite report |last1=Wright |first1=David |title=Colliding Satellites: Consequences and Implications |publisher=Union of Concerned Scientists |date=26 February 2009 |url=https://www.ucs.org/sites/default/files/2019-10/SatelliteCollision-2-12-09.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{wright2009colliding, author = {Wright, David}, title = {{Colliding Satellites: Consequences and Implications}}, institution = {Union of Concerned Scientists}, year = {2009}, month = feb, url = {https://www.ucs.org/sites/default/files/2019-10/SatelliteCollision-2-12-09.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }