Fine Guidance Sensor/Near InfraRed Imager and Slitless Spectrograph (FGS/NIRISS)
The Fine Guidance Sensor (FGS) allows Webb to point precisely, so that it can obtain high-quality images. The FGS was delivered to NASA Goddard in July of 2012.
Learn More About FGS/NIRISS:
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. FGS is a "guider," which helps point the telescope.
FGS/NIRISS is being built by the Canadian Space Agency.