The James Webb Space Telescope Observatory - Optical Telescope Element (OTE)

    The Optical Telescope Element (OTE) is the eye of the James Webb Space Telescope Observatory. The OTE gathers the light coming from space and provides it to the science instruments. Webb needs a large mirror to collect as much light as possible to see galaxies from the beginning of the Universe. Webb scientists and engineers have determined that a primary mirror 6.5 meters (21.3 feet) across is what was needed to measure the light from these galaxies.

    The OTE has 2 other components: the Fine Steering Mirror (FSM); and the structural pieces to hold everything together. The structural pieces include [the secondary mirror support structure (SMSS) and the primary mirror backplane assembly.

    The OTE tertiary mirror and the fine steering mirror are both contained within an OTE subsystem known as the Aft Optics Subsystem. The backplane, in addition to holding the OTE together will be where the Integrated Science Instrument Module (ISIM), which contains the instruments, is installed in the Observatory.

