The Herschel satellite

The Herschel Space Observatory carries the largest, most powerful infrared telescope ever flown in space. It is helping astronomers understand how the Universe came to be what it is today.

Herschel is the first space observatory to observe from the far-infrared to the submillimetre waveband, unveiling the mysterious hidden cold Universe to us for the first time. It is exploring further in the far-infrared than any previous mission, studying otherwise invisible dusty and cold regions of the cosmos, both near and far.

Herschel taps into previously unexploited wavelengths, seeing phenomena out of reach of other observatories, at a level of detail that has not been captured before. The telescope's primary mirror is 3.5 m in diameter, more than four times larger than any previous infrared space telescope and almost one and a half times larger than that of the Hubble Space Telescope. The telescope collects almost twenty times more light than any previous infrared space telescope.

The satellite consists of four main parts. The telescope, the payload (the instruments and the cryostat which cools everything), the service module (electronics and communication), and the sunshield to protect the payload from direct solar illumination.

The spacecraft carries three advanced science instruments: two cameras and a very high resolution spectrometer; their detectors are cooled to temperatures close to absolute zero by a sophisticated cryogenic system.

 

HIFI

PACS

SPIRE

Primary mirror: 3.5 m in diameter. Herschel's mirror is the largest ever built for a space telescope mission.  The bigger the telescope mirror, the more light it collects; big mirrors mean that we can see fainter objects and we can distinguish fine details. 

Launch: 14th May 2009 on board an Ariane 5 from ESA's Spaceport in Kourou, French Guiana. Herschel was launched along with Planck, ESA's microwave observatory which is studying the Cosmic Microwave Background.

Journey: Herschel separated from the upper stage of the launcher about 26 minutes after launch, Planck followed a few minutes later. The observatory reached its operational orbit about a hundred days after launch.
 
Orbit: Herschel orbits around a special point in space (called 'L2') located about 1.5 million km from Earth in the direction opposite to the Sun.

Lifetime: A minimum of three years for routine science observations. The mission will last until the cryostat runs out of helium, about four years after launch (2013).

Instruments: HIFI (Heterodyne Instrument for the Far Infrared), a high-resolution spectrometer, PACS (Photoconductor Array Camera and Spectrometer), SPIRE (Spectral and Photometric Imaging REceiver).  Together, these instruments cover the range 55–672 microns, nearly a thousand times longer than the wavelength of visible light. Their detectors are cooled to temperatures very close to absolute zero (-273 degrees C).

Launch mass: About 3.4 tonnes.
 
Dimensions: About 7.5 m high and 4 m wide.

Operations: Herschel is operated as an observatory. It operates autonomously, sending acquired data to Earth over a three-hour period every day.

Primary ground station: ESA's deep space antenna in New Norcia, Australia.