Details Related A test version of ESA’s Proba-V Companion CubeSat seen during preparation for ‘thermal balance’ testing in the Agency’s Mechanical Systems Laboratory at its ESTEC technical centre in the Netherlands. Space is a place where it is possible to be hot and cold at the same time, if one part of your satellite is in sunlight and another face in shade. A satellite’s interior needs to maintain a steady temperature to go on operating properly. Accordingly this ‘structural and thermal model’ of the Proba-V Companion CubeSat was placed inside the Large Vacuum Facility of ESA’s Mechanical Systems Laboratory – employed to test large satellite systems or complete small satellites – for a week-long exposure to temperature extremes in space-quality vacuum.