Debris environment definition to assess effectiveness of measures taken to reduce spacecraft vulnerability

Techniques for assessing the exposure of spacecraft surfaces to a limiting debris size and to penetration related characteristics such as crater diameter or surface penetration have been developed within a phase space definition of the debris environment. This approach requires the use of the full three dimensional description of the flux density distribution in the co- moving frame of the spacecraft. In this paper results of a simple modeling approach are used to generate debris environment and penetration related characteristics for the manmade debris environment as defined in the Space Station Natural and Induced Environment Document (SSP 30425), for a manmade environment derived of USSPACECOMMAND catalog element sets, and for the reference meteoroid environment in SSP 30425. Assuming the spacecraft is protected by an aluminum Whipple two-sheet shield, techniques for reducing shielding weight for a given reliability will be presented and results using this technique for several convex structural shape will be discussed.