The Herschel Space Observatory

The Herschel Space Observatory is the fourth cornerstone mission in the European Space Agency (ESA) science programme. Herschel will be equipped with a passively cooled 3.5-m diameter Cassegrain telescope and three scientific instruments - HIFI, PACS and SPIRE - which together will carry out sensitive imaging and spectroscopy in the FIR and submillimetre range, covering wavelengths between 57 and 670 mum. This paper summarises the design and scientific capabilities of Herschel and its instruments.