Fine Guidance Sensor and Near Infrared Imager and Slitless Spectrograph

Fine Guidance Sensor and Near Infrared Imager and Slitless Spectrograph (FGS-NIRISS) is an instrument on the James Webb Space Telescope (JWST) that combines a Fine Guidance Sensor and a science instrument, a near-infrared imager and a spectrograph.

[7] FGS helps provide data to the JWST Attitude Control System (ACS) and to do this it has a big sky coverage and sensitivity, to give a high probability it can find a guide star.

The FGS is designed to find pre-selected guide stars, which allows the telescope to stay precisely pointed at the desired target.

[16] In July 2011 the Canadian Space Agency reluctantly discontinued work on the Tunable Filter Imager (TFI) when it became clear that issues associated with the cryogenic operation of its Fabry-Perot etalon were unlikely to be resolved in time to meet the instrument's delivery schedule... A developmental version of the TFI was tested in Ontario, Canada in 2010.

[15] Related institutions and the science team for the instrument includes:[7] Canada credits work on the FUSE (Far Ultraviolet Spectroscopic Explorer) as helping them prepare for making JWST FGS.