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Design and Lessons Learned on the Development of a Cryogenic Pupil Select Mechanism Used in the Testing and Calibration of the Integrated Science Instrument Module (ISIM) on the James Webb Space Telescope (JWST)Calibration and testing of the instruments on the Integrated Science Instrument Module (ISIM) of the James Webb Space Telescope (JWST) is being performed by the use of a cryogenic, full-field, optical simulator that was constructed for this purpose. The Pupil Select Mechanism (PSM) assembly is one of several mechanisms and optical elements that compose the Optical Telescope Element SIMulator, or OSIM. The PSM allows for several optical elements to be inserted into the optical plane of OSIM, introducing a variety of aberrations, distortions, obscurations, and other calibration states into the pupil plane. The following discussion focuses on the details of the design evolution, analysis, build, and test of this mechanism along with the challenges associated with creating a sub arc-minute positioning mechanism operating in an extreme cryogenic environment. In addition, difficult challenges in the control system design will be discussed including the incorporation of closed-loop feedback control into a system that was designed to operate in an open-loop fashion.
Document ID
20140013464
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Mitchell, Alissa
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Capon, Thomas
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Guzek, Jeffrey
(SGT, Inc. Greenbelt, MD, United States)
Hakun, Claef
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Haney, Paul
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Koca, Corina
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Date Acquired
November 11, 2014
Publication Date
May 14, 2014
Subject Category
Optics
Report/Patent Number
GSFC-E-DAA-TN13639
Meeting Information
Meeting: Aerospace Mechanisms Symposium
Location: Baltimore, MD
Country: United States
Start Date: May 14, 2014
End Date: May 16, 2014
Sponsors: NASA Goddard Space Flight Center, Lockheed Martin Space Operations
Funding Number(s)
CONTRACT_GRANT: NNG07CA21C
Distribution Limits
Public
Copyright
Public Use Permitted.
Keywords
Testing
Design and lessons learned
Calibration
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