Development and sizing of the JWST Integrated Science Instrument Module (ISIM) metering structure

Kunt, Cengiz; Johnston, John D.; Bartoszyk, Andrew; Hendricks, Steve

doi:10.1117/12.670112

Cited by 8 publications

(3 citation statements)

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“…2 The ISIM Structure is an approximately 2m x 2m x 1.5m bonded composite frame that acts as a metering structure between the instruments/guider and the telescope. 3,4 The ISIM Structure interfaces to the OTE via a kinematic mount (KM) system consisting of two bipods and two monopods. The ISIM Structure and the supported instruments are designed to operate at cryogenic temperatures (~35 K), and thermal distortion performance is critical to maintaining the alignment of the instruments to the ISIM Structure.…”

Section: Overview Of Jwst Isim and The Isim Structurementioning

confidence: 99%

Cryogenic thermal distortion model validation for the JWST ISIM structure

Johnston

Cofie

2011

SPIE Proceedings

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The James Webb Space Telescope (JWST) Integrated Science Instrument Module (ISIM) Structure is a precision optical metering structure for the JWST science instruments. Optomechanical performance requirements place stringent limits on the allowable thermal distortion of the metering structure. A significant effort was completed to develop capabilities to predict and metrologize cryogenic thermal distortion of the ISIM Structure. This paper focuses on thermal distortion finite element modeling, analysis, and model validation. Extensive thermal distortion analysis was completed during the design phase for the ISIM Structure to demonstrate that thermal distortion requirements were achieved. Comparison of measurements from recently completed cryogenic testing and model predictions demonstrate the adequacy of thermal distortion modeling uncertainty factors adopted during the design phase, and provide bounds on the accuracy of the model predictions. This paper will provide an overview of the test configurations, describe the thermal distortion models of the tests, and provide a comparison of test results and analytical predictions from the models.

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Section: Overview Of Jwst Isim and The Isim Structurementioning

confidence: 99%

Cryogenic thermal distortion model validation for the JWST ISIM structure

Johnston

Cofie

2011

SPIE Proceedings

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“…Therefore it is main ly used to support optics and sensitive equipment. For examp le, the kinematic mounting is used for the James Webb Space telescope to connect all the scientific instruments, which contain FGS, NIRSpec, NIRCam, and MIRI, to the ISIM structure [1][2][3] .The scientific instruments on Hubble Space Telescope are connected to the main body structure via the kinemat ic mount [4] .The main optical elements of the Spitzer telescope are connected to the back-end instrument platform through the kinematic mount [5] .…”

Section: Introductionmentioning

confidence: 99%

Design and analysis of the kinematic mount between the space camera and the satellite platform

Sun

Xue

et al. 2023

Advanced Fiber Laser Conference (AFL2022)

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A kinematic mount based on the statically determinate principle is designed using a single-axis right circular flexure hinge. The main role of this support structure is to reduce the influence the satellite platform on the space camera, thereby ensuring the thermal stability of the space camera in orbit. The mathematical model of the compliance of the single-axis right circular flexure hinge is derived based on the Castigliano’s second theorem. According to the index requirements and the compliance equations, the initial structure of kinematic mount is obtained. The optimization design is conducted with the initial structure as the optimization object and the natural frequency as the optimization objective to obtain the optimal structure. The finite element analysis shows that the optimal structure meets the index requirements. Compared with the initial structure, the natural frequency of the optimal structure is increased by 4.2%, the optimal structure in Rx, Ty, and Tz are better than the initial structure 13.3%, 21%, and 12.8%. Experiment verifications of compliance equation C33 of single-axis right circular flexure hinge and the compliance of the bipod are carried out. The experiment results indicate that the compliance equation C33 is correct, and the compliance of the bipod meets the design value. Therefore, it is concluded that all the compliance equations are correct, and the kinematic mount can meet the requirements of the thermal stability of the space camera in orbit.

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Section: Introduction 11 Overview Of Jwst Isim and The Isim Structurementioning

confidence: 99%

Cryogenic thermal distortion performance characterization for the JWST ISIM structure

et al. 2011

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The James Webb Space Telescope (JWST) Integrated Science Instrument Module (ISIM) Structure is a precision optical metering structure for the JWST science instruments. Optomechanical performance requirements place stringent limits on the allowable thermal distortion of the metering structure between ambient and cryogenic operating temperature (~35 K). This paper focuses on thermal distortion testing and successful verification of performance requirements for the flight ISIM Structure. The ISIM Structure Cryoset Test was completed in Spring 2010 at NASA Goddard Space Flight Center in the Space Environment Simulator Chamber. During the test, the ISIM Structure was thermal cycled twice between ambient and cryogenic (~35 K) temperatures. Photogrammetry was used to measure the Structure in the ambient and cryogenic states for each cycle to assess both cooldown thermal distortion and repeatability. This paper will provide details on the post-processing of the metrology datasets completed to compare measurements with performance requirements.

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Development and sizing of the JWST Integrated Science Instrument Module (ISIM) metering structure

Cited by 8 publications

References 0 publications

Cryogenic thermal distortion model validation for the JWST ISIM structure

Cryogenic thermal distortion model validation for the JWST ISIM structure

Design and analysis of the kinematic mount between the space camera and the satellite platform

Cryogenic thermal distortion performance characterization for the JWST ISIM structure

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