The UK ATC is part of a consortium of 15 institutes in the UK, France, Spain, Italy, Sweden and the USA which was formed to build SPIRE, the Spectral and Photometric Imaging REceiver instrument for the Herschel Space Observatory.
The Herschel Space Observatory is the fourth major (cornerstone) mission in ESA's horizon 2000 programme and, with a 3.5m primary mirror, it will be the biggest space telescope yet flown. Herschel will provide the astronomical community with a powerful multi-purpose observatory capable of observations in the relatively un-explored 50-700 micron wavelength range.
SPIRE is one of three instruments which will be used with the Herschel telescope. It has been optimised for astronomy which can only be done from space. By measuring the far infrared and submillimetre emission from gas and dust heated by young stars SPIRE will help astronomers understand the physics of star formation and will enable the detection of galaxies forming in the very early Universe.
In collaboration with other institutes the UK ATC participated in the project start-up and developing the overall instrument design, and made major contributions to the initial opto-mechanical design of the photometer channels (ie. the camera optics and layout), and the concepts for the chopper or beam steering mechanism. The UK ATC is responsible for the design, testing and manufacture of the beam steering mechanism. We are also contributing to the focal plane systems engineering, a key role in ensuring that the final instrument performance will meet the astronomical requirements. We are also contributing effort towards the instrument control centre design - the software necessary to deal with the data that SPIRE will produce.
The beam steering mechanism is the first mirror that the infrared light from the telescope will encounter when it enters the instrument. It can be moved rapidly back and forth between various positions, so that the detectors measure alternately regions of the astronomical source of interest and a nearby region of sky. This chopping motion is necessary because it means that changes in the background infrared radiation entering the telescope can be removed from the astronomical signal, improving the accuracy and sensitivity of the measurements.
Herschel will be launched jointly with the PLANCK mission in 2007 and, after reaching orbit, the two telescopes will separate and operate independently.