Accession Number : ADA292302

Title :   Overview of the Space Debris Environment.

Corporate Author : AEROSPACE CORP EL SEGUNDO CA TECHNOLOGY OPERATIONS

Personal Author(s) : Meshishnek, M. J.

PDF Url : ADA292302

Report Date : 15 MAR 1995

Pagination or Media Count : 34

Abstract : There is a component of the space environment that is man-made pollution, termed "space debris" it exists at all inclinations and, primarily, at altitudes of roughly 350 km to 2000 km. The size of this debris ranges from several meters to a fraction of a micrometer in diameter, and the particle distribution follows an inverse power law, with the smaller size component far exceeding that of the larger. Debris is composed primarily of alumina from solid rocket motor exhausts, aluminum from spacecraft structures, and zinc and titanium oxides from thermal control coatings. The accepted model of the space debris environment is that of Kessler et al., a complex model that predicts the number of particles that will impact a surface as a function of altitude, inclination, solar cycle, and particle diameter, as well as their collision velocities. Recent data from LDEF has demonstrated both the accuracy and shortcomings of the Kessler model. Measured debris impactor fluxes are in good agreement with the model for ram surfaces. However, predictions of the model for other surfaces of a spacecraft are less accurate, most notably for the wake or trailing side. While the Kessler model is appropriate for long-term, average flux predictions, spatial-temporal impact fluxes measured on LDEF dramatically illustrated the presence of strong debris clouds that do not dissipate quickly in space and will encounter an orbiting spacecraft cyclically and repeatedly over its lifetime. LDEF data has also indicated the presence of debris in elliptical orbits, a fact not predicted by the Kessler model. This fact is responsible for the discrepancy between measured impact fluxes and predictions on trailing edge surfaces.

Descriptors :   *DEBRIS, *SPACE ENVIRONMENTS, *POLLUTION, THERMAL PROPERTIES, VELOCITY, ORBITS, CLOUDS, DIAMETERS, SPACECRAFT, IMPACT, SIZES(DIMENSIONS), PREDICTIONS, MODELS, DISTRIBUTION, FLUX(RATE), ACCURACY, SURFACES, COATINGS, PARTICLES, ALUMINUM OXIDES, ALUMINUM, MANMADE, WAKE, ZINC, TEMPERATURE CONTROL, SPACECRAFT COMPONENTS, INVERSION, POWER, SIDES, SAMPLERS, SOLID PROPELLANT ROCKET ENGINES, SOLAR CYCLE, COLLISIONS, STRUCTURAL COMPONENTS, TITANIUM OXIDES, ROCKET EXHAUST, ELLIPTICAL ORBIT TRAJECTORIES.

Subject Categories : Astronautics

Distribution Statement : APPROVED FOR PUBLIC RELEASE