ESA
Herschel became the largest infrared telescope ever sent to space when it launched in May 2009. Its purpose was to observe the coldest and dustiest regions in space, generally invisible to other telescopes.
The telescope's vital supply of liquid helium coolant — needed to cool the spacecraft's sensitive detectors and prevent heat from obscuring the far-infrared light it was built to detect – was used up at the end of April.
Controllers sent the final command to Herschel on June 17 and moved it into an orbit around the sun after draining the last of its fuel. The satellite may never have contact with Earth again but its legacy will endure through the tens of thousands of scientific observations it made during its brief lifetime.