Spacecraft Module Hole Size and Crack Length Prediction Following a Penetrating Debris Particle Impact

The process used to calculate and reduce the consequences of meteoroid and orbital debris (MOD) penetrations and their link to catastrophic failure has evolved over time. As the threat of the orbital debris population increased in the 1980s and early 1990s, NASA developed a tool to determine the probability of no catastrophic failure, or PNCF, for the space station and to assess possible changes in station design and/or operations to improve that survivability percentage. PNCF is directly related to the PNP, or probability of no penetration, as calculated by Bumper, the code used by NASA to perform MOD risk assessments. Part of the process in determining PNCF involves calculating the size of the holes and cracks caused by any penetrations. In this paper, the features of new generic hole- and crack-size prediction equations, as well as the phenomenology involved in the formation of holes and cracks in habitable space station modules are presented and discussed. When these new hole and crack size equations are used in survivability assessments, the fidelity of the PNCF calculations and predictions are expected to increase dramatically.