5 September 2017 JWST center of curvature test method and results
Author Affiliations +
The James Webb Space Telescope (JWST) recently saw the completion of the assembly process for the Optical Telescope Element and Integrated Science Instrument Module (OTIS). This integration effort was performed at Goddard Space Flight Center (GSFC) in Greenbelt, Maryland. In conjunction with this assembly process a series of vibration and acoustic tests were performed. To help assure the telescope’s primary mirror was not adversely impacted by this environmental testing an optical center of curvature (CoC) test was performed to measure changes in the mirror’s optical performance. The primary is a 6.5 meter diameter mirror consisting of 18 individual hexagonal segments. Each segment is an off-axis asphere. There are a total of three prescriptions repeated six times each. As part of the CoC test each segment was individually measured using a high-speed interferometer (HSI) designed and built specifically for this test. This interferometer is capable of characterizing both static and dynamic characteristics of the mirrors. The latter capability was used, with the aid of a vibration stinger applying a low-level input force, to measure the dynamic characteristic changes of the PM backplane structure. This paper describes the CoC test setup, an innovative alignment method, and both static and dynamic test results.
Conference Presentation
© (2017) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Babak Saif, David Chaney, Perry Greenfield, Kyle Van Gorkom, Keira Brooks, Warren Hack, Marcel Bluth, Josh Bluth, James Sanders, Koby Smith, Larkin Carey, Sze Chaung, Ritva Keski-Kuha, Lee Feinberg, Severine Tournois, W. Scott Smith, Vladimir Kradinov, "JWST center of curvature test method and results", Proc. SPIE 10401, Astronomical Optics: Design, Manufacture, and Test of Space and Ground Systems, 104010T (5 September 2017); doi: 10.1117/12.2273974; https://doi.org/10.1117/12.2273974

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