Telescope
 Image credit: Airbus Defence & Space |
The design of the Euclid telescope is mainly driven by the requirements to provide both excellent visible channel imaging quality and a simultaneous field for near-infrared spectroscopy and photometry.
The Euclid telescope is a three mirror Korsch configuration with a 0.45 deg off-axis field and an aperture stop at the primary mirror. The entrance pupil diameter is 1.2 metres, the optically corrected and unvigneted field of view is 0.79 × 1.16 deg², and the focal length is 24.5 m.
In order to meet the scientific performance requirements, such as having internal background well below the zodiacal sky background, the telescope must operate at a reduced temperature - a maximum operating temperature of about 240 K can be tolerated for the telescope.