Portal de Periódicos da CAPES

Verification of the James Webb Space Telescope Integrated Science Instrument Module cryogenic structural alignment requirements via photogrammetry

2008; SPIE; Volume: 7068; Linguagem: Inglês

10.1117/12.798791

1996-756X

Maria Nowak, Paul Cleveland, Allen Crane, Pamela S. Davila, Acey Herrera, Jason E. Hylan, Andrew D. Liehr, J. G. Marsh, Raymond G. Ohl, Kevin Redman, Henry P. Sampler, Joseph M. Stock, Greg Wenzel, Robert A. Woodruff, Philip J. Young,

Astronomy and Astrophysical Research

The alignment philosophy of the James Webb Space Telescope (JWST) Integrated Science Instrument Module (ISIM) is such that the cryogenic changes in the alignment of the science instruments (SIs) and telescope-related interfaces are captured in an alignment error budget. The SIs are aligned to the structure's coordinate system under ambient, clean room conditions using laser tracker and theodolite metrology. The ISIM structure is thermally cycled and temperature-induced mechanical and structural changes are concurrently measured to ensure they are within the predicted boundaries. We report on the ISIM photogrammetry system and its role in the cryogenic verification of the ISIM structure. We describe the cryogenic metrology error budget and the analysis and testing that was performed on the ISIM mockup, a full scale aluminum model of the ISIM structure, to ensure that the system design allows the metrology goals to be met, including measurement repeatability and distortion introduced from the camera canister windows.