Hypervelocity impact experiments on aerogel dust collector

Autor: Akira Fujiwara, Kichiro Imagawa, Toshihiko Kadono, Yukihito Kitazawa, Kazuo Uematsu, Okada Yutaka
Rok vydání: 1999
Předmět:
Zdroj: Journal of Geophysical Research: Planets. 104:22035-22052
ISSN: 0148-0227
DOI: 10.1029/1998je000554
Popis: Laboratory hypervelocity impact experiments were conducted to verify the performance of aerogel dust collectors used for gathering meteorolds and space debris in the near-Earth environment and to derive the relationships of various parameters characterizing the projectile with morphology of tracks left by the penetrating projectile in the aerogel collector pad. Silica aerogel collectors of 0.03 g/cm - density were impacted at velocities ranging from 1 to 14 km/s with projectiles of aluminum oxide, olivine, or soda- lime glass, with diameters ranging from 10 to 400/xm. At impact velocities below 6 km/s the projectiles were captured without fragmentation by the aerogel collector and, in many instances, without complete ablation even at 12 km/s. The shapes and dimensions of the penetration tracks left in the aerogel collector were correlated with the impact parameters, and the results permitted derivation of a series of equations relating the track dimensions to incoming projectile size, impact energy, and other projectile parameters. A simplified model, similar to meteor-entry phenomena, was used to predict the trends in experimental penetration track lengths and the diameters of captured projectiles. Solid particles present in the near-Earth environment derive from either natural or artificial origin and are termed "mete- oroids" and "space debris", respectively. Meteoroids are con- sidered to be supplied from comets, asteroids, and planets, and some known as interstellar dust particles or interstellar grains are from outside the solar system (Griin et al., 1993). Since meteoroids are thought to be closely related with the evolution of the solar system, study of these materials provides us with crucial information on the source materials for the solar sys- tem. In situ sampling of meteoroids in space can avoid con- tamination by terrestrial sources, which is unavoidable in sam- pling on Earth. Space debris is the product of normal satellite operations, the deterioration of satellites, and the fragmentation or breakup of satellites (Johnson and McKnight, 1991). It is im- portant to investigate micrometer-to-millimeter-sized debris, the range within which the majority of debris particles lie, because this changes the characteristics of the materials of spacecraft or of the on-board parts after colliding with them. The distribution and composition of small-sized debris are not well known, as these particles are too small to be observed with ground-based telescopes or radars. In situ sampling of dust particles is useful for getting material information on the de
Databáze: OpenAIRE
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