Herschel: the birth of the stars [ Return towards  Cryogenics: cold for space  ]

This observation will make it possible to detect objects (galaxies and stars being formed, for example) whose visible emission is so weak that the most sensitive optical telescopes can’t observe them.

Equipped, among others, with a 3.5-meters-diameter mirror, it will become the largest telescope ever sent into space. Its mission should last about three years.

The detection instruments onboard Herschel are cooled to about 1.5K by means of the superfluid helium stored in a tank called a cryostat. Air Liquide designed and manufactured this extraordinary 2,400-liter tank. Its impermeability is a key element for the entire duration of this mission: the telescope’s functioning directly depends on the available helium and, when this helium is totally evaporated, the mission will come to an end.

In the framework of this program, Air Liquide has moreover delivered other equipment, in particular a second liquid helium tank for tests on the ground, helium transportation lines, as well as heat shields that insulate the tanks and instruments from the exterior environment.

Herschel weighs about 3.3 tons and measures nearly 9 meters.