Description: ACTA and Sandia National Laboratories propose to quantify and propagate substructure modeling uncertainty for reduced-order substructure models to higher levels of system assembly, thereby enabling predictive simulations of engineering designs with quantified margins and uncertainties for model-based flight qualification of complete spacecraft. A critical part of this process is the accurate modeling of interface structures, especially nonlinear interface structures that connect major substructures, and the quantification of their uncertainties. By developing generic uncertainty models for reduced order models of specific substructures, NASA will be able to quantify margins and uncertainties for structural systems outside the domain of model validation tests.

Benefits: The Air Force has requirements similar to NASA's for launch environment model V&V and qualification testing. While Air Force spacecraft may not approach the size of some NASA spacecraft, such as the NASA space station for example, Air Force satellites may have instrumentation appendages that cannot be tested in an earth-gravity environment. So, potential non-NASA applications stand to benefit from the proposed technology in the same ways as NASA applications.

NASA has long been required to ground-test spacecraft and spacecraft components in their launch configuration for model verification, validation and flight qualification because of the severity of the dynamic environment. Ground-testing of spacecraft in their on-orbit configurations is usually impractical because they are not designed to withstand earth-gravity forces. The ability to quantify modeling uncertainty at the substructure level and propagate it to system levels could obviate the need for launch environment model V&V and qualification testing, and enable the assessment of predictive accuracy for on-orbit modeling as well. This technology has potential application to virtually all NASA spacecraft.