mission involved three instruments utilizing a very large (3.5m wide) telescope. This telescope featured the largest one-piece mirror in space, and was considerably larger than any of its predecessors, including the Hubble space telescope.
Researchers from many countries and institutions in Europe and North America worked together to build the three very complex and sensitive instruments on Herschel:
HIFI, PACS, and SPIRE
Heterodyne Instrument for the Far Infrared, HIFI,
was a high-resolution spectrometer that looks at a single point in the sky. A spectrometer is an instrument that splits light into the light spectrum, its individual components. HIFI was built in the Netherlands, and Canada contributed hardware components to this very complex instrument.
Photometric Array Camera and Spectrometer, PACS,
was an infrared spectrometer and camera. It received infrared light, ranging in wavelength from 60 to 200µm, not just from one point, but a small patch in the sky. It was assembled and tested in Germany.
Spectral and Photometric Imaging Receiver, SPIRE,
was similar to PACS in that it was an infrared camera plus spectrometer that looked simultaneously at a whole region in the sky. However, it observed in the longer wavelength range from 200 to 670µm. It was assembled and tested in the UK. The University of Lethbridge leads the Canadian contribution to SPIRE, which is funded by the Canadian Space Agency.