Probabilistic Assessment of
Space Shuttle Debris
Transport & Impact
Mechanics & Materials
Space shuttle launch
NASA Johnson Space Center (JSC)
Develop a probabilistic analysis methodology and tool to predict probability of impact and damage to the Space Shuttle thermal protection system (TPS) components due to debris impact, and perform an independent verification of NASA-JSC debris transport analysis.
As a result of the conclusion that debris impact caused the damage to the left wing of the Columbia Space Shuttle Launch Vehicle (SSLV) during ascent, the Columbia Accident Investigation Board recommended that an assessment be performed of the debris environment experienced by SSLV during ascent. Eliminating the possibility of debris transport is not possible; therefore, a flight rationale based on probabilistic assessment is required for the SSLV return-to-flight. The assessment entails identifying all potential debris sources, their probable geometric and aerodynamic characteristics, and their potential for impacting and damaging TPS components.
There are a multitude of uncertainties in the debris transport process. Experimental evidence indicates that a range of debris shapes, typically thin and roughly conical, can be shed from the foam insulation covering the external tank. During the transport of debris after release, drag forces act to slow the debris thereby increasing the speed relative to the SSLV. In addition to the highly stochastic nature of the release and transport of debris, uncertainties exist in the atmospheric conditions, mission profile, impact conditions, and TPS material properties.
A probabilistic debris transport analysis (DTA) model was developed based on transport models developed by NASA-JSC. Problem setup, definition and analyses were performed within the SwRI-developed NESSUS® probabilistic analysis software. NASA-JSC simulations were verified using the NESSUS-based DTA model.
Thacker, B.H., D.S. Riha, J.B. Pleming, L.J. Huyse, R.J. Gomez and P.C. Stuart, "Development and Verification of a Probabilistic Model for Space Shuttle Debris Transport ," Proc. AIAA/ASME/ASCE/AHS/ASC 47th Structures, Structural Dynamics, and Materials (SDM) Conf, Newport, RI, 1-4 May, 2006.
Team Members:David S. Riha, Luc J. Huyse and Jason B. Pleming
injury analysis • mechanics and materials • structural integrity • reliability assessment • mechanical behavior • mechanical characterization, fatigue life characterization • crack growth • corrosion fatigue • probabilistic mechanics • uncertainty modeling • bone fracture • bone properties