Space Station Module Wall Hole Size and Crack Length Following Orbital Debris Penetration at 6.5 km/s

The threat of damage from high speed meteoroid and orbital debris particle impacts has become a significant design consideration in the development and construction of long duration earth-orbiting spacecraft. Historically, significant amounts of resources have been devoted to developing shielding for such structures as a means of reducing the penetration potential of high speed on-orbit impacts. These efforts have typically focused on simply whether or not the inner (or pressure) walls of candidate multi-wall structural systems would be perforated. Only recently the nature and extent of pressure wall penetration damage have begun to be explored. This paper presents the results of a study whose objective was to characterize the hole formation and cracking phenomena associated with the penetration of some of the multi-wall systems being considered for the International Space Station Alpha (ISSA). Empirical equations were developed for effective hole size and maximum tip-to-tip crack length in the event of a module penetration. These equations can be used in a survivability analysis to determine whether or not module unzipping would occur under a specific set of impact conditions and the time available for module evacuation prior to the onset of incapacitation due to air loss.