Description: The objective for the Phase II effort will be to develop a comprehensive, efficient, and flexible uncertainty quantification (UQ) framework implemented within a matured user-friendly software, which will enable the modeling of both inherent and epistemic uncertainties in spacecraft system models, have a general quantification of margins and uncertainties (QMU) capability for system certification and reliability assessment, and utilize advanced methods based on non-intrusive polynomial chaos (NIPC) for efficient and accurate propagation of mixed (inherent+epistemic) uncertainties as also demonstrated under the Phase I effort. In the proposed project, an adaptive uncertainty quantification methodology, which will successively utilize different NIPC methods depending on the size of the problem along with the non-linear global sensitivity information, will be implemented to address the computational expense of UQ in complex spacecraft system simulations with large number of uncertain variables. The developed UQ framework and QMU capability will be demonstrated on a large-scale spacecraft system model that is of interest to NASA. This proposed work will compliment M4 Engineering's expertise in developing simulation technologies that solve relevant demonstration applications. The researchers from MS&T (RI) will guide the implementation of UQ and QMU methodologies and contribute to the proposed effort with their UQ expertise in aerospace simulations.

Benefits: M4 Engineering has active relationships with several prime contractors who are likely users of this technology. These include Boeing Phantom Works, Northrop Grumman, and Raytheon. These provide excellent commercialization opportunities for the technology. The application of these new uncertainty quantification techniques is expected to find wide application to many aerospace and non-aerospace products. The non-intrusive approach for uncertainty propagation is a widely applicable concept. Examples include aerospace/defense, turbomachinery, automotive, and alternative energy applications.

The first NASA application will be performed as a demonstration example during the Phase II project. One candidate for this example will be the SWOT program. It is also expected that this technology will be applicable to other research projects planned at JPL. The effectiveness in reducing the total runtime associated with UQ makes it an ideal candidate for use in computationally demanding systems requiring complex analyses to characterize the design space. Examples of potential application include future space systems, next generation launch and entry systems such as HMMES and HRRLS as well as exploration programs, high efficiency subsonic aircraft, quiet supersonic aircraft, high-altitude, long-endurance aircraft, and hypersonic aircraft. This effort will develop technologies to make use of high fidelity, physics-based UQ analysis earlier in the design cycle. It is therefore applicable in general to any NASA vehicle application. While initial implementation is expected for space applications, applications to future concepts in aeronautics also have potential. This proposal addresses NASA's goals by proposing state of the art advances in UQ methods. The tools developed can be used with an integration framework, and will be widely applicable to space systems as well as subsonic and supersonic vehicles including unconventional designs. By making these analyses available earlier in the design process, more effective vehicle systems can be generated while maintaining safety.