'Heart' Of Herschel Space Observatory Almost Ready

The Herschel mission, equipped with the largest telescope ever launched in space (3.5 m diameter), will give astronomers their best capability yet to explore the universe at far-infrared and sub-millimetre wavelengths. By measuring the light at these wavelengths, scientists see the ‘cold’ universe. Herschel will give them an unprecedented view, allowing them to see deep into star forming regions, galactic centres and planetary systems.

In order to achieve its objectives and to be able to detect the faint radiation coming from the coolest objects in the cosmos, otherwise ‘invisible’, Herschel’s detectors must operate at very low and stable temperatures.

The spacecraft is equipped so as to cool them close to absolute zero (-273.15 ºC), ranging from -271 ºC to only a few tenths of a degree above absolute zero. To have achieved this particular feature alone is a remarkable accomplishment for European industry and science.

The final integration of the various components of the Herschel spacecraft – payload module, cryostat, service module, telescope and solar arrays – will be completed in the next few months. This phase will be followed by a series of tests to get the spacecraft ready for launch at the end of July 2008.

Herschel will be launched into space on an Ariane 5 ECA rocket. The launch is shared with Planck, ESA’s mission to study relic radiation from the Big Bang.

Contractors and funding

The Prime Contractor for the Herschel spacecraft is Thales Alenia Space (Cannes, France). It leads a consortium of industrial partners with Astrium (Germany) responsible for the Extended Payload Module (EPLM, including the Herschel cryostat), Astrium (France) responsible for the telescope, and the Thales Alenia Space industry branch of Torino, Italy, responsible for the Service Module (SVM). There is also a host of subcontractors spread throughout Europe.

The three Herschel instruments were designed and built by consortia of scientists and institutes, with their own national funding. The Photodetector Array Camera and Spectrometer (PACS) was developed under the coordination of the MPE, Germany; the Spectral and Photometric Imaging Receiver (SPIRE) was developed under the coordination of the Cardiff University (United Kingdom); the Heterodyne Instrument for the Far Infrared (HIFI) was developed under the coordination of the SRON institute (The Netherlands).