Launched by Ariane 5 in May 2009, the European Space Agency’s Herschel Space Observatory (formerly called Far InfraRed and Submillimetre Telescope or FIRST) is the first of a new generation of space telescopes – bigger than any of its predecessors at approximately seven and a half metres high and four metres wide and weighing around three tons, it is the first space observatory covering the full far-infrared and sub-millimetre waveband, and the largest to work at those wavelengths. It is located 1.5 million kilometres away from Earth, around the second Lagrangian point, farther than any previous space telescope.
Airbus Defence and Space’s ground-breaking developments in lightweight silicon-carbide technology were fundamental to the realisation of this programme; the company built the satellite’s all-silicon carbide (SiC) space telescope, which is collecting the light from distant and poorly known objects, such as newborn galaxies thousands of millions of light-years away.
SiC is an exceptional material whose mechanical-thermal properties allow the manufacture of ultra lightweight but very large instruments: the Airbus Defence and Space mirror, at 3.5m, is the largest imaging telescope ever launched, and yet the Herschel telescope weighs just 350kg, as opposed to the 1.5 tons which would be required with standard technology.
Under a second contract, Airbus Defence and Space was responsible for the fully integrated payload module that consisted of the:
In order to prevent the instruments' own infrared radiation from drowning out the received signal, they are cooled inside a cryogenic unit – called a cryostat – down to –271° C (about two degrees above absolute zero). At this temperature the sensitive science instruments have the potential to penetrate the unknown areas of the cold, early universe.
The cryostat is the central unit of the payload module and was built under the leadership of Airbus Defence and Space. The low temperature is achieved using superfluid helium. For the construction of cryostat, Airbus Defence and Space was able to draw on the experience it gained from Herschel's precursor, the European Infrared Space Observatory (ISO) which was successfully operated from 1996 to 1998.