The Rosetta orbiter lies in a vast empty space, inhabited only by its orbital companion – a 4 Km wide ball of ice and dust, spitting out gases and other material as it is warmed by the Sun’s rays.  It’s next mission milestone comes on August 13th, 2015, when the duo reaches perihelion, the closest point to the Sun in their orbit.  It will be the first time a spacecraft has the opportunity to study the outgassing and behaviour of a comet as it orbits close to the Sun.  So far the comet 67P/ Churyumov-Gerasimenko has been slowly increasing in...