MMOD Risk to the International Space Station and its Sensitivity to Particle Size

This paper will provide a summary of the latest meteoroid and orbital debris (MMOD) risk assessment of the International Space Station (ISS) produced by the Hypervelocity Impact Technology (HVIT) group at the NASA Johnson Space Center. Major updates include using the most current orbital debris engineering model (ORDEM 3.2) and the latest meteoroid environment model (MEM 3). Failure criteria associated with this baseline risk analysis is defined as threshold perforation of a pressurized module and it incorporates a simplified seven-step assembly sequence to model the time between first element launch in November 1998 and the assembly complete stage in February 2010. Updated model configurations were used to represent changes to the ISS for the period between 2010 and 2025. In addition to failures that could lead to depressurization of both the U.S. and Russian segments, data will be presented about the risks to other non-critical hardware that may lead to operational failures by impacts from smaller MMOD particles.