The MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) instrument is part of the payload of the European Space Agency's (ESA) earth observation satellite ENVISAT-1. Most of the optical imaging equipment of MIPAS is required to operate at a temperature level around 200 K. The detectors and their optics have to be cooled down to approximately 70 K. Various thermal design measures have been taken to achieve these goals.
In order to verify the thermal design the instrument behaviour has been represented in a mathematical model. A software tool for reduction of thermal models has been used to obtain small models for various purposes. The verification of the instrument thermal design also includes a thermal balance test.