Long term consequences of the Iridium 33 - Cosmos 2251 collision
- Paper number
IAC-09.A6.2.4
- Author
Dr. Alessandro Rossi, ISTI-CNR, Italy
- Coauthor
Dr. Giovanni B. Valsecchi, INAF/IASF, Italy
- Coauthor
Dr. Ettore Perozzi, Telespazio S.p.A., Italy
- Coauthor
Dr. Donald R. Davis, Planetary Science Institute, United States
- Year
2009
- Abstract
The collision between the Iridium 33 satellite and the non functioning Cosmos 2251 spacecraft showed dramatically how the collision risk against space debris is now a serious threat to all the space activities. This collision could be particularly dangerous for the space environment due to the peculiar orbital configuration of the Iridium constellation. As we showed in (Rossi, Valsecchi and Farinella, {\it Nature}, 399, 1999) a near polar multi-plane constellation, such as Iridium, is particularly at risk of a collisional cascade if one of its satellite is first accidentally fragmented. Unfortunately, what was a "gedankenexperiment" at the time of the {\it Nature} paper, became now reality. In this paper we apply the method described in the previous work, showing how the real cloud of objects behaves with respect to the other constellation planes. The present collision happened on the third plane of the Iridium constellation. As showed in the {\it Nature} paper, the plane number three is one of the most protected planes, in dynamical terms. For this reason the resulting cloud does not encounter the nearby constellation planes in an unfavourable head-on geometry in the aftermath of the fragmentation (e.g., as would have been the case for a fragmentation happening on plane number six). Using the orbits of the real fragments, together with a simulated mass distribution, the evolution of the collision risk over a time span of a few decades is studied. Some considerations on the applicability of the currently adopted fragmentation models can also be drawn from the analysis of the evolution of the observed debris cloud.- Abstract document
- Manuscript document
(absent)