You forget to mention that it operated one year longer than intended.
And it discovered alot
Herschel was instrumental in the discovery of an unknown and unexpected step in the star forming process. The initial confirmation and later verification via help from ground-based telescopes of a vast hole of empty space, previously believed to be a dark nebula, in the area of NGC 1999 shed new light in the way newly forming star regions discard the material which surround them.[39]
In July 2010 a special issue of Astronomy and Astrophysics was published with 152 papers on initial results from the observatory.[40]
A second special issue of Astronomy and Astrophysics was published in October 2010 concerning the sole HIFI instrument, due its technical failure which took it down over 6 months between August 2009 and February 2010.[41]
It was reported on 1 August 2011, that molecular oxygen had been definitively confirmed in space with the Herschel Space Telescope, the second time scientists have found the molecule in space. It had been previously reported by the Odin team.[42][43]
An October 2011 report published in Nature states that Herschel's measurements of deuterium levels in the comet Hartley 2 suggests that much of Earth's water could have initially come from cometary impacts.[44] On 20 October 2011, it was reported that oceans-worth of cold water vapor had been discovered in the accretion disc of a young star. Unlike warm water vapor, previously detected near forming stars, cold water vapor would be capable of forming comets which then could bring water to inner planets, as is theorized for the origin of water on Earth.[45]
On 18 April 2013, the Herschel team announced in another Nature paper that it had located an exceptional starburst galaxy which produced over 2,000 solar masses of stars a year. The galaxy, termed HFLS3, is located at z = 6.34, originating only 880 million years after the Big Bang.[46]
Just days before the end of its mission, ESA announced that Herschel's observations had led to the conclusion that water on Jupiter had been delivered as a result of the collision of Comet Shoemaker–Levy 9 in 1994.[47]
On 22 January 2014, ESA scientists using Herschel data reported the detection, for the first definitive time, of water vapor on the dwarf planet, Ceres, largest object in the asteroid belt.[48][49] The finding is unexpected because comets, not asteroids, are typically considered to "sprout jets and plumes". According to one of the scientists, "The lines are becoming more and more blurred between comets and asteroids."[49]
