Which company built JWST's FGS/NIRISS instrument?

Honeywell built JWST’s FGS/NIRISS instrument. Honeywell International designed and built the hardware in collaboration with the Canadian Space Agency and the instrument’s science team, led by principal investigator René Doyon.

FGS/NIRISS combines two functions in one package. The Fine Guidance Sensor helps Webb lock onto guide stars and maintain extremely steady pointing, while NIRISS—the Near Infrared Imager and Slitless Spectrograph—performs specialized near-infrared imaging and spectroscopy.

NIRISS is a Canadian contribution to the international Webb mission. Technical support also came from the National Research Council of Canada’s Herzberg Astronomy and Astrophysics Research Centre. The instrument’s development history is sometimes described using COM DEV, the Canadian company that developed the hardware before being acquired by Honeywell; that is why older references may name COM DEV instead.

A frequent mix-up is attributing every Webb instrument to the same contractor. Lockheed Martin built NIRCam, Ball Aerospace built NIRSpec, and Airbus led development of MIRI, whereas FGS/NIRISS is associated with Honeywell and Canada.