Inside Herschel

This picture shows an artist's impression of the view inside Herschel.

To protect the sensitive instruments from heat generated during operations and to achieve its challenging objectives, the satellite must operate at very low temperatures. This is why the spacecraft’s brain – or its payload module – hosts a cryostat, a cryogenic module inside which the cold components of the scientific instruments are mounted.

Inside the cryostat the sensitive instrument detectors are cooled down to about -273 ºC (0.3 degrees above absolute zero). This low temperature is achieved using superfluid helium (at about -271 ºC) and an additional cooling stage inside the focal plane units.

The service module is the spacecraft’s heart, which keeps the spacecraft going by caring for all its vital functions. It also carries the ‘warm’ components of the instruments – those that do not require cooling with the cryostat.