ON SEMI-ACTIVE SHIELDING PROTECTION OF SPACECRAFT FROM METEOROIDS AND ORBITAL DEBRIS

摘要

For increase of fragmentation and kinetic energy of tangential scattering of fragments (in the system of the mass centre of a cloud of fragments) it is proposed to use in structure of protection chemically active materials. There is a possibility to use the reaction directly between components of protection shield and orbital medium particles. For this purpose it is supported to use a mesh shield which elements are able to penetrate into indenter deeply. Then, the reaction surface area is increased considerably and the reaction will occur not only in a thin layer near the contact surface but in the tracks generated in the particle just behind the penetrative elements of a shield (in the vapor phase). Most of materials of orbital debris are characterized by a high reaction heat with halogens, oxygen and sulfur. The analysis performed on the current stage allows us to come to conclusion that the most promising materials are polyfluoro-olefins, for example, polytetrafluorethylene [-C_2F_4-]_n (PTFE, fluorocarbon polymer F4). This material is quite enough stable under orbital conditions and, at the same time, it provides with a large energy effect in the reactions with orbital medium particles. The submitted results of experiments testify to non-thermal character of reaction initiation in conditions of joint plastic deformation PTFE and aluminum at impact. E. Christiansen (JSC of NASA) made contribution to the semi-active shielding idea too.