The European Space Agency’s Jupiter Icy Moons Explorer (Juice) has begun a critical sequence of tests to make sure it can function correctly in the hostile conditions of outer space. Having been assembled by Airbus Friedrichshafen, Germany, the 6.2 tonne spacecraft has now arrived at Esa’s European Space Research and Technology Centre (ESTEC) in the Netherlands, where it is being prepared to enter the Large Space Simulator. Once inside, the air will be pumped from the chamber to replicate the vacuum of space. Then it will be heated and cooled to precisely mimic its varying distance from the Sun as it journeys through the solar system to arrive at the gas giant planet Jupiter, five times further from the Sun than the Earth. The tests are scheduled to take 31 days to complete. After this, Juice will be shipped to Toulouse for a final round of tests before being transported to Europe’s spaceport in Kourou, French Guiana for launch. Lift off will take place next year on an Ariane 5 rocket. Upon arrival at Jupiter in 2029, Juice will begin an extensive investigation of the planet and its oceanic moons: Europa, Ganymede and Callisto to investigate the conditions necessary for habitability.