The European Space Agency's Herschel Space Observatory (formerly called Far Infrared and Sub-millimetre Telescope or FIRST) has the largest single mirror ever built for a space telescope. At 3.5-metres in diameter the mirror will collect long-wavelength radiation from some of the coldest and most distant objects in the Universe. In addition, Herschel is the only space observatory to cover a spectral range from the far infrared to sub-millimetre.
Herschel, originally named FIRST (Far InfraRed and Sub-millimetre Telescope), was renamed in honour of Sir William Herschel, who in 1800 demonstrated the existence of infrared light. Both he and his sister Caroline Herschel were pioneering and successful astronomers.
|Mass||About 3400 kg at launch|
|Dimensions||7.5m high, 4m × 4m overall cross section|
|Launcher||Ariane 5 ECA from Guiana Space Centre|
|Mission Lifetime||3 years nominal from end of commissioning phase|
|Wavelength||Infrared and sub-millimetre: 55 to 672 µm|
|Telescope||Cassegrain, 3.5m primary and 0.3m secondary mirror|
|HIFI (Heterodyne Instrument for the Far Infrared)||Very high resolution heterodyne spectrometer||Frank Helmich, Space Research Organization Netherlands (SRON) (Groningen, The Netherlands)|
|PACS (Photodetector Array Camera and Spectrometer)||Imaging photometer / medium resolution grating spectrometer||Albrecht Poglitsch, Max-Planck Institut für Extraterrestrische Physik (MPE) (Garching, Germany)|
|SPIRE (Spectral and Photometric Imaging Receiver)||Imaging photometer / imaging Fourier transform spectrometer||Matthew Griffin, University of Wales (Cardiff, United Kingdom)|
Herschel was launched on an Ariane 5 ECA rocket together with ESA's Planck spacecraft on 14 May 2009, at 13:12:02 UTC. The two spacecraft separated after launch and were directly injected towards the second Lagrange point of the Sun-Earth system, L2. About sixty days after launch, Herschel entered a Lissajous orbit around the L2 point at a distance of around 1.5 million km from Earth, on Earth's nightside. The spacecraft's orbit around L2 has an average amplitude of about 700 000 km and a period of about 178 days.
Herschel's Mission Operations Centre (MOC) is located at ESA's European Space Operations Centre (ESOC) in Darmstadt, Germany and is responsible for the daily operations, health and safety of the spacecraft. For communication with the spacecraft ESA's New Norcia (close to Perth, Australia) and Cebreros (close to Avila, Spain) deep space antennas are used, with New Norcia serving as the main ground station. In the phase immediately after launch the Kourou (French Guiana) and Villafranca (Spain) ground stations were also used.
The Herschel science operations team is situated in the Herschel Science Centre (HSC) at ESA's European Space Astronomy Centre (ESAC) in Villanueva de la Cañada in Spain.
The Herschel instrument control centres for monitoring and optimising the instruments' performance are located at:
|for PACS:||the Max Planck Institute for Extraterrestrial Physics, Garching, Germany;|
|for SPIRE:||the Rutherford Appleton Laboratory, UK;|
|for HIFI:||SRON Netherlands Institute for Space Research, the Netherlands.|
An additional centre is the NASA Herschel Science Center located at the California Institute of Technology Infrared Processing and Analysis Center, Pasadena, California, USA.