Optical Telescope Element (OTE)
The OTIS (OTE+ISIM) out of cryovac chamber at NASA Johnson. The OTIS is an acronym that includes the OTE plus the Integrated Science Instrument (ISIM) package - essentially the optics and science instruments. Credit: NASA/Chris Gunn
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. The OTE consists of the mirrors as well as structures and subsystems that support the optics.
The OTE Consists Of :
- 6.5 meter diameter primary mirror made of 18 hexagonal segments
- Round 0.74 meter Secondary mirror (image gallery)
- Tertiary mirror (image gallery) and Fine Steering Mirror, both of which are contained in the Aft Optics Subsystem (image gallery).
- Telescope structure (image gallery) (which includes the primary mirror backplane assembly, the main backplane support fixture (BSF), the secondary mirror support structure, and the deployable tower array) The BSF will house the instrument module.
- Thermal Management Subsystem
- Aft Deployable ISIM Radiator (ADIR)
- Wavefront sensing and control
Source: James Webb Space Telescope (NASA.gov)