Herschel closes its eyes on the Universe

[Waspie_Dwarf]

Herschel closes its eyes on the Universe

17 April 2013 ESA’s Herschel space observatory has exhausted its supply of liquid helium coolant, ending more than three years of pioneering observations of the cool Universe.

The event was not unexpected: the mission began with over 2300 litres of liquid helium, which has been slowly evaporating since the final top-up the day before Herschel’s launch on 14 May 2009.

The liquid helium was essential to cool the observatory’s instruments to close to absolute zero, allowing Herschel to make highly sensitive observations of the cold Universe until today.

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[stevewinn]

so what now for Herschel? does it just stay in orbit?

[Waspie_Dwarf]

so what now for Herschel? does it just stay in orbit?

It's not actually in an Earth orbit, it is orbiting the L2 Lagrangian point, more than a million Km from Earth. As such it is too far away to order it to re-enter the atmosphere and burn up. Instead it will be sent out of it's L2 orbit into an orbit around the Sun so that it will be a potential hazard to other missions using the L2 point.