The JWST MIRI FM wheel mechanisms characterisation for open loop drive

Örs Hunor Detre; Ulrich Grözinger; Oliver Krause; Friedrich Müller; Silvia Scheithauer

doi:10.1117/12.926661

13 September 2012 The JWST MIRI FM wheel mechanisms characterisation for open loop drive

Örs Hunor Detre, Ulrich Grözinger, Oliver Krause, Friedrich Müller, Silvia Scheithauer

Proceedings Volume 8450, Modern Technologies in Space- and Ground-based Telescopes and Instrumentation II; 84501Z (2012) https://doi.org/10.1117/12.926661
Event: SPIE Astronomical Telescopes + Instrumentation, 2012, Amsterdam, Netherlands

Abstract

The high reliability of the mechanisms of any space instrument is one of the most critical and challenging requirements. This is even more pronounced in the case of cryogenic instruments, such as the Mid-Infrared Instrument (MIRI) to be flown on the James Webb Space Telescope (JWST) – which will be cooled down to below 7 K. MIRI hosts three wheel mechanisms for filter, grating and dichroic selection. All of them have an open loop torque drive and thus the precise characterisation of the mechanisms and their motors is fundamental to achieve minimum heat load and maximum reliability of the mechanism movements over the lifetime. In this paper we present the overview of the characterisation and verification of the MIRI wheel mechanisms. Our method is based on measuring back EMF voltages generated by the two phase cold redundant motors of the wheel mechanisms after they had been fully integrated into the MIRI optical module. We present the analysis of the data and the resulting performance increase. We discuss the optimisation of the open loop drive, as well as the verification of the measurement results and the physical model of the motors and mechanisms.

Citation Download Citation

Örs Hunor Detre, Ulrich Grözinger, Oliver Krause, Friedrich Müller, and Silvia Scheithauer "The JWST MIRI FM wheel mechanisms characterisation for open loop drive", Proc. SPIE 8450, Modern Technologies in Space- and Ground-based Telescopes and Instrumentation II, 84501Z (13 September 2012); https://doi.org/10.1117/12.926661

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available