NASA and Canadian Space Agency (CSA) engineers install the Fine Guidance Sensor (FGS) / Near-InfraRed Imager and Slitless Spectrograph (NIRISS) instrument package onto the Webb Telescope's Integrated Science Instrument Module (ISIM). The FGS/NIRISS was built by the Canadian Space Agency and delivered to NASA Goddard in July of 2012.
The Fine Guidance Sensor (FGS) allows Webb to point precisely, so that it can obtain high-quality images. The Near Infrared Imager and Slitless Spectrograph part of the FGS/NIRISS will be used to investigate the following science objectives: first light detection, exoplanet detection and characterization, and exoplanet transit spectroscopy. It has a wavelength range of 0.8 to 5.0 microns, and is a specialized instrument with three main modes, each of which addresses a separate wavelength range.