


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. The OTE consists of the mirrors as well as structures and subsystems that support the optics.
Primary Mirror and Support Structure
18 Hexagonal Segments, 6.5 meter diameter
SECondary Mirror and Support Structure
Round, .74 meter diameter
AFT Optics Subsystem
Tertiary and Fine Steering Mirrors
THERMAL MANAGEMeNT SYSTEM
The Webb Observatory is the space-based portion of the James Webb Space Telescope system. It is comprised of the Optical Telescope Element (OTE), the Integrated Science Instrument Module (ISIM), the sunshield and the spacecraft bus.
The OTE Consists Of:
- PRIMARY MIRROR: 6.5 meter diameter primary mirror made of 18 hexagonal segments
- About Webb's Mirrors | Gallery (new tab)
- SECONDARY MIRROR: Round 0.74 meter Secondary mirror (image gallery)
- Gallery (new tab)
- TERTIARY MIRROR and FINE STEERING MIRROR
- Gallery (new tab)
- Both contained in the Aft Optics Subsystem (Gallery new tab).
- TELESCOPE STRUCTURE:
- Gallery (new tab)
- Includes:
- the primary mirror backplane assembly (About)
- the secondary mirror support structure,
- the main backplane support fixture (BSF), which houses the instrument module (About).
- the deployable tower array
- THERMAL MANAGEMENT SYSTEM
- AFT DEPLOYABLE ISIM RADIATOR (ADIR)
- WAVEFRONT SENSING AND CONTROL SYSTEM (About)






