Hypervelocity Impact Testing Of Betacloth Covers On Space

Two major satellite breakups, the worst in 20 months, occurred just four weeks apart in the fourth quarter of 2001, both producing in excess of 300 large fragments. Two other lesser breakup events brought the total number of satellite fragmentations to nine for the year, a rate not matched since 1998., experienced a significant fragmentation while in an orbit just 30 km above the International Space Station (ISS), i.e., 411 km mean altitude for Cosmos 2367 and 382 km for ISS. Approximately 200 debris were detected by normal US Space Surveillance Network (SSN) operations, while special sensor observations several days after the event indicated that another 100 or more smaller debris were also in orbit. These debris were concentrated in the orbital regime of 200-500 km, but some were thrown into orbits with apogees above 1000 km. Approximately 40% of the debris were immediately thrown into orbits which crossed the orbit of ISS. Immediately upon notification of the breakup, the Orbital Debris Program Office undertook an effort to characterize the probable debris cloud and to assess the risks posed by it not only to the ISS but also to the imminent STS-108 mission. Naval Space Command , headquartered in Dahlgren, Virginia, spearheaded the effort to identify the individual debris and to develop initial orbital parameters for each. Throughout Thanksgiving and the following weekend, NASA and Naval Space Command personnel worked to gain a better insight into the extent of the newly created debris cloud. The STS-108 mission, then planned for launch on 29 November, raised new safety issues. The Space Shuttle is not as well protected from small debris impacts as ISS. Specific concerns were STS-108 overall mission risks, EVA risks, risks associated with boosting ISS during the mission, and risks associated with special Space Shuttle attitudes planned during independent flight. Fortunately, these new risks were assessed to be within NASA guidelines. Cosmos 2367 was the latest in the Cosmos 699 series of 3-metric-ton spacecraft which began in 1974. To date 20 of these spacecraft have undergone one or more fragmentation episodes with the number of debris generated usually on the order of 100 or more. Most of the events have occurred at relatively low altitudes, resulting in relatively rapid decay of the debris. In the case of Cosmos 2367 some of the debris should remain in orbit for many months. About three weeks after the Cosmos 2367 breakup, the …