ESA's Herschel space-borne infrared observatory will carry the largest telescope ever flown in space. A pioneering mission to study the formation and evolution of stars and galaxies, it will help understand how the Universe came to be what it is today.
Herschel will observe the immensity of space, from objects within our own Solar System, to the stars of the Milky Way and the giant clouds of gas and dust from which they form, to galaxies in the far Universe, back 10 thousand million years in the past. It will do this by exploring further in the far-infrared than any previous space observatory, looking through otherwise invisible dusty and cold regions of the cosmos.
Herschel will conduct observations in a wide range of wavelengths, the longest of which are still unexploited. These are the 'magic key' that will open a new window to the earliest phases of a star's life and so reveal the youngest stars in the Galaxy, further to possible planets forming around them.
The observatory will be able to focus on details that no one has seen before. Its ability to see the molecules that make the cocoons of dust and gas from which baby-stars emerge will tell us more about star formation than any of its predecessors.
Herschel will also see, for the first time in its entirety, the vast reservoir of gas constituting half the normal matter in our Galaxy.
Looking further away in space and time, Herschel will take the first census of galaxies which are at the peak of star formation throughout the Universe.
This will be a giant leap in the effort to chart the history of star formation and the evolution of galaxies in the cosmos.
The spacecraft carries a telescope and three advanced instruments. Their detectors are kept at temperatures close to absolute zero by a sophisticated cryogenic system.
Launch: 2009, on an Ariane 5 ECA rocket from Kourou, French Guyana
Orbit: around the 2nd Lagrangian Point, or L2, located at about 1.5 million km from Earth in the direction opposite to the Sun
Lifetime: approximately 4 years
Captions of inset images:
Image 1
Cryostat cool-down
The Herschel spacecraft set up for the cool-down of its cryostat and for the filling of its main cryogenic tank with liquid Helium. The temperature in the cryostat has gradually been lowered over a period of weeks to avoid
temperature differences and resulting mechanical stress.
Image 2
Herschel M1/M2 distance measurements
The Herschel telescope was tested for opto-mechanical stability during M1/M2 distance tests. The distance between the primary and the secondary mirror was checked using a high-precision laser tracker, that is accurate in the order of microns. The device is in the foreground, on the left.
Image 3
Herschel being prepared for acoustic tests
During the tests, the spacecraft was subjected to acoustic noise, generated to simulate the noise levels during launch, at the European Space Research and Technology Centre’s Large European Acoustic Facility (LEAF)
