Integrated Modeling of the James Webb Space Telescope: pre-Launch Predictions,Flight Performance and Lessons Learned

Because of its size and complexity, the Observatory performance of the James Webb Space Telescope (JWST) in its operating condition was primarily verified by analysis prior to launch, breaking the standard NASA paradigm of test-as-you-fly. Most of the requisite analytical predictions were achieved through Integrated Modeling which combines models of the various physics and subsystem behaviors affecting system-level performance: thermal, jitter, structures thermal distortion, gravity release and alignments, optics, wavefront sensing and control, attitude control, straylight and launch loads analysis. We will briefly describe the process by which models were managed, constructed, verified, validated, and used to support the analyses. We will address how uncertainties were accounted for given the many unknowns of the nanometric performance of the first-of-its-kind large deployable cryogenic precision optics in space. Finally, we will compare the pre-flight predictions to actual performance on-orbit for several key analysis use cases and conclude with lessons learned for future missions.