Herschel Completes Mission in Space
7 May 2013
The Herschel Space Observatory, built and operated by the European Space Agency, exhausted its supply of liquid helium coolant in late April and was forced to cease operations because it is unable to continue conducting its most sensitive observations without the fluid.
During its mission, which began in 2009, the observatory made more than 35,000 observations and collected over 25,000 hours' worth of science data. It had the largest single mirror ever built for a space telescope, which helped scientists uncover some of the universe's secrets by showing what's happening on the frigid side of the planet and how stars and galaxies form and evolve.
Liquid helium was required to keep the instrumentation of the telescope cooled and scientists confirmed that it was running out of the coolant during a daily communication session with the spacecraft's ground station in Western Australia, when a notable increase in temperature was detected in all of the instruments.
The spacecraft was launched aboard an Ariane 5 rocket from French Guiana in May 2009, giving astronomers the chance to see the darkest and coldest objects in space that cannot be observed with other telescopes, said John Grunsfeld, associate administrator for NASA's Science Mission Directorate at NASA headquarters in Washington.
Herschel was valued for its ability to observe the heat of celestial objects rather than the light emitted and it helped astronomers trace the path of water throughout our surrounding universe. The mission was also successful in the discovery of some of the youngest stars and was the first to detect cold water vapor enveloping a dusty disk around a young star, suggesting that water-covered planets like Earth may be common in the universe