Cassini – Huygens is a robotic space mission mission co-operated by NASA / ESA / ASI with the task of studying Saturn and its natural satellites.
Cassini is running out of fuel. When the fuel runs out, scientists won't be able to control Cassini in the right way.
NASA controllers ordered Cassini to commit suicide by plunging through Saturn's atmosphere, according to the BBC. The ship survived for about a minute before breaking.
In addition to the European Space Agency's Philae probe, the recent landing on comet 67P has six other outstanding missions underway.