Protecting the Space Station from Meteoroids and Orbital Debris (1997) / Chapter Skim
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3: METEOROID AND DEBRIS ENVIRONMENT MODELS
3: METEOROID AND DEBRIS ENVIRONMENT MODELS
Pages 18-26
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From page 18... ...
radars, the U.S. Space Command satellite catalog, the Massachusetts Institute of Technology experimental test site telescope (Taff et al., 1985)
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From page 19... ...
Unlike earlier models, this model begins by defining a population of debris divided into six inclination bands, two eccentricity families, and six size ranges. These populations are based on the existing data, but, where data are lacking, estimates derived from the complex NASA EVOLVE model (Reynolds, 1993)
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From page 20... ...
A third change is that the predicted average impact velocity has been reduced. (The small increase in average collision velocity due to collisions with objects in elliptical orbits is overshadowed by the reduction in average collision velocities for the much larger population of objects in nearly circular orbits.)
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From page 21... ...
Further efforts to more accurately determine the current population of these objects in the ISS orbit, however, may not be the most effective way to help improve the models. At the altitude of the ISS, atmospheric drag steadily removes debris from orbit, and new debris may enter the altitude band as satellites and rocket bodies break up, solid rocket motors eject slag, and the orbits of higher-altitude objects decay.
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From page 22... ...
A major gap exists in the available data about another key size range of meteoroids and debris. Figure 3-4 shows the various data sources used in developing the NASA meteoroid and debris environment models.
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From page 23... ...
band; 4% per year for other bands for altitudes with little atmospheric drag Reduced population growth at lower altitudes, decreasing to no growth at about 200 km Based on Haystack, catalog, and other sources Unchanged Unchanged Predominant source Breakups Breakups Breakups and solid of objects larger than rocket motor ejecta 1 cm Includes debris in No No Yes elliptical orbits Approximate number 0 0 2 x 1 o-5 per square of impacts of objects meter larger than 0.5 cm in diameter with ISS trailing surfaces over 10 years
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From page 24... ...
Recent NASA analysis of data from the Haystack radar suggests that aluminum oxide ejected from solid rocket motors may be the most common debris detectable from Earth in the ISS orbit (Reynolds and Zhang, 1996~. Fragments from the breakup of spacecraft and rocket bodies may be the second most common debris.
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From page 25... ...
NASA should continue to update the 1996 debris environment model by using new data and analyses. Efforts should focus on improving understanding of the processes that add and remove objects in the 0.5 to 20 cm size range from the International Space Station altitude regime, the sources and characteristics of smaller debris down to 1 mmin diameter, and debris composition and shape.
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From page 26... ...
Briefing presented to the NRC Committee on International Space Station Meteoroid/Debris Risk Management, Houston, Texas, April 1, 1996. Stansbery, E.G., T.E.
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