NASA - National Aeronautics and Space Administration

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. FGS is a "guider," which helps point the telescope.

The FGS was delivered to NASA Goddard during the summer of 2012. Here is a photo of it during testing:

FGS/NIRISS is being built by the Canadian Space Agency.

Jump to: NIRCam, NIRSpec, or MIRI instrument.

Want to know more?  Visit the James Webb Space Telescope project home page.