Iridium 33 and Cosmos 2251 collide
An operational American communications satellite and a defunct Russian military satellite collided at an altitude of about 790 kilometres over Siberia, at a closing speed on the order of eleven kilometres per second. It was the first accidental hypervelocity collision between two intact satellites, and it produced roughly two thousand catalogued fragments. Thirty-one years after the collision cascade was described in the literature, the mechanism was demonstrated — and the demonstration made conjunction assessment and collision avoidance a routine operating cost for every satellite operator rather than an abstraction.
Historical — it happened, and the record is settled.
Subjects
- Orbital debris · phenomenon · not located
- The Kessler collision cascade · model · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent.
ESA Annual Space Environment Report
Supports the catalogued and modelled debris population magnitudes, the altitude dependence of orbital decay, and the fragment contributions of the 2007 Fengyun-1C test, the 2009 Iridium–Cosmos collision and the 2021 Cosmos 1408 test. V55 verification basis: esa.int was refused by the network egress proxy in this session and no search was available, so counts are given as ranges and no edition-specific number is quoted.
European Space Agency, Space Debris Office · Partly verified
ESA Space Debris Office, ESA Annual Space Environment Report, Darmstadt, annual series
Recorded on Orbital debris
- Kessler and Cour-Palais publish the collision cascade argument
- The UN adopts voluntary space debris mitigation guidelines
- A Chinese anti-satellite test destroys the Fengyun-1C weather satellite
- Iridium 33 and Cosmos 2251 collide
- The first sixty Starlink satellites are deployed
- A Russian anti-satellite test destroys Cosmos 1408
- The FCC adopts a five-year post-mission disposal rule
Related
Related because they share a subject in the Atlas — never because the text looks similar.
- The FCC adopts a five-year post-mission disposal rule · 2022-09-29
- A Russian anti-satellite test destroys Cosmos 1408 · 2021-11-15
- The first sixty Starlink satellites are deployed · 2019-05-24
- A Chinese anti-satellite test destroys the Fengyun-1C weather satellite · 2007-01-11
- The UN adopts voluntary space debris mitigation guidelines · 2007
- Kessler and Cour-Palais publish the collision cascade argument · 1978