The Fine Guidance Sensor for the James Webb Space Telescope
- Paper number
IAC-05-A3.1.01
- Author
Dr. Neil Rowlands, COM DEV Ltd., Canada
- Year
2005
- Abstract
The James Webb Space Telescope (JWST) is a 6.6 m, passively cooled deployable telescope which will orbit the L2 earth-sun point beginning in 2011. NASA is leading the development of the Observatory with their partners the European Space Agency and the Canadian Space Agency. The Canadian contribution to the mission is the Fine Guidance Sensor (FGS). The primary function of the FGS is to provide continuous pointing information to the Observatory that is used to stabilize the line of sight, allowing JWST to obtain the required image quality. There are three primary science instruments, NIRCam, NIRSpec and MIRI, which are located in the JWST focal plane along with the FGS. The FGS also incorporates a flexible narrow spectral band science imaging capability in the 1 to 5 µm wavelength range, which adds to the scientific capabilities of the mission.
The FGS consists of an Optical Assembly and a set of instrument control electronics. The Optical Assembly of the FGS instrument consists of two modules, each with two channels. The first module (the guider module) images two separate regions of the JWST field of view (FOV) onto two independent 2k x 2k focal plane arrays. These two channels are dedicated to the guider function. The second, science imaging module, consists of a single FOV that is simultaneously imaged by two separate 2k x 2k focal plane arrays in two different wavelength regions. Each of these FGS–TF channels, designated short and long, contain a filter wheel and a scanning Fabry-Perot etalon that allow flexible imaging with a spectral resolution of 100, in the two wavelength bands simultaneously.
The FGS is currently in the detailed design phase and we report here on the design progress overall, while highlighting certain aspects of the design, notably the etalon design which enables the flexible narrow-band imaging capability.
- Abstract document
- Manuscript document
IAC-05-A3.1.01.pdf (🔒 authorized access only).
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