Selection of Critical Design Parameters for MMOD Protection in Interplanetary Missions

AbstractThis paper presents a methodology for the selection of critical design-parameters for the design of Micro Meteoroid and Orbital Debris (MMOD) spacecraft protection based on a modified implementation of the concept of the Probability of No Impact (PNI). The PNI methodology, based on Poisson's discrete statistics, has been widely used to determine critical particle sizes for the design of protection systems. However, it does not provide guidelines for the selection of the design impact speed, especially when the impact speed has a very wide statistical distribution like that encountered in interplanetary missions. The modifications to the PNI methodology presented here allows for the selection of both, a design particle size and impact speed, based on the same discrete probability theory. This methodology is applied to determine critical design parameters for the Solar Probe Plus (SPP) spacecraft; a mission currently under study funded by the NASA's Office of Space Science – Sun-Earth Connection theme. Results are presented for the Solar Array in the SPP spacecraft in the form of design particle size and impact speed for various PNI levels