Global alignment optimization strategies, procedures, and tools for the James Webb Space Telescope (JWST) Integrated Science Instrument Module (ISIM)

摘要

During cryogenic vacuum testing of the James Webb Space Telescope (JWST) Integrated Science Instrument Module(ISIM), the global alignment of the ISIM with respect to the designed interface of the JWST optical telescope element(OTE) will be measured through a series of optical characterization tests. These tests will determine the locations andorientations of the JWST science instrument projected focal surfaces and entrance pupils with respect to theircorresponding OTE optical interfaces. Thermal, finite element and optical modeling will then be used to predict the on-orbitoptical performance of the observatory. If any optical performance non-compliances are identified, the ISIM willbe adjusted to improve its performance. If this becomes necessary, ISIM has a variety of adjustments that can be made.The lengths of the six kinematic mount struts that attach the ISIM to the OTE can be modified and five scienceinstrument focus positions and two pupil positions can be individually adjusted as well. In order to understand how tomanipulate the ISIM’s degrees of freedom properly and to prepare for the ISIM flight model testing, we have completeda series of optical-mechanical analyses to develop and identify the best approaches for bringing a non-compliant ISIMElement back into compliance. During this work several unknown misalignment scenarios were produced and thesimulated optical performance metrics were input into various mathematical modeling and optimization tools todetermine how the ISIM degrees of freedom should be adjusted to provide the best overall optical performance.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.