Cabin Environment Physics Risk Model
Speaker: Chris Mattenberger, Science and Technology Corporation / Applied Modeling & Simulation Branch, NASA Ames Research Center
Presentation
Abstract
The Cabin Environment Physics Risk (CEPR) model estimates the time for an initial failure of Environmental Control and Life Support System (ECLSS) functionality on a crewed spacecraft to propagate into a hazardous environment and trigger a loss-of-crew (LOC) event. This physics-of-failure model allows a probabilistic risk assessment of a crewed spacecraft to account for the cabin environment, which can serve as a buffer to protect the crew during an abort from orbit and ultimately enable a safe return. The results of the CEPR model replace the assumption that failure of the crew-critical ECLSS functionality causes LOC in all cases, and provide a more accurate representation of the spacecraft’s risk posture. The all-LOC assumption is shown to be excessively conservative and, moreover, can impact the relative risk drivers identified for the spacecraft. This, in turn, could lead the design team to allocate mass for equipment to reduce overly conservative risk estimates in a suboptimal configuration, which inherently increases the overall risk to the crew. Discussed is an example where available mass could be poorly used to add redundant ECLSS components that have a negligible benefit but appear to make the vehicle safer due to poor assumptions about the propagation time of ECLSS failures.
Biography
Chris Mattenberger is a Research Scientist/Engineer with the Science and Technology Corporation. His work since 2008 has focused on supporting risk-informed design and decision making as a member of several NASA organizations. Currently, he is a member of the Engineering Risk Assessment team at NASA Ames Research Center, supporting analysis of satellites, launch vehicles, crewed spacecraft, and space mission architectures. Previously, he was involved with the NASA Constellation Program and served as lead reliability analyst with the Lunar Lander Program Office as well as the Spacecraft Conceptual Design Office at NASA Johnson Space Center. Earlier, Mattenberger received a Bachelor of Science in Aerospace Engineering with Information Technology from the Massachusetts Institute of Technology in 2006, and went on to earn a Master of Science in Aeronautics and Astronautics from Stanford University in 2008. He was recognized with a NASA Accomplishment Award in 2008 for his work on the Altair Lunar Lander, and was recognized with a NASA Group Achievement Award in 2013 for his work on the Commercial Crew Engineering Risk Assessment Team.