The term JWST Observatory refers to the space-based portion of the JWST system and is comprised of three elements:

• the Integrated Science Instrument Module (ISIM)
• the Optical Telescope Element (OTE) (includes the mirrors)
• the Spacecraft Element (Spacecraft Bus and Sunshield)

Here are two labeled artist's conceptions of the spacecraft. Click on each one for a larger version.

The Integrated Instrument Module (ISIM) includes the following science instruments:

• Mid-Infrared Instrument (MIRI)
  
• Near-Infrared Spectrograph (NIRSpec)
  
• Near-Infrared Camera (NIRCam)
  
• Fine Guidance Sensor (FGS)

The OTE is the eye of the JWST Observatory. The OTE gathers the light coming from space and provides it to the science instruments located in the ISIM.

The sunshield subsystem separates the observatory into a warm sun-facing side (spacecraft bus) and a cold anti-sun side (OTE and ISIM). The sunshield keeps the heat of the Sun, Earth, and spacecraft bus electronics away from the OTE and ISIM so that these pieces of the Observatory can be kept very cold (The operating temperature has to be kept under 50 K or -370 deg F).

The spacecraft bus provides the support functions for the operation of the JWST Observatory. The bus houses the six major subsystems needed to operate the spacecraft: the Electrical Power Subsystem, the Attitude Control Subsystem, the Communication Subsystem, the Command and Data Handling Subsystem, the Propulsion Subsystem, and the Thermal Control Subsystem.

If you want to learn more about the structure and parts of the spacecraft, try your hand at building our JWST paper model!

Learn more about the different parts of JWST, and compare it to a simple hand-held telescope by playing our "Scope It Out" game!