Lowering the ‘structural and thermal model’ test version of the mammoth FCI, Flexible Combined Instrument, for Meteosat Third Generation into ESA's Large Space Simulator for thermal vacuum testing during June 2018. Some 15 m high and 10 m in diameter, the Large Space Simulator – located at ESA’s ESTEC technical centre in the Netherlands – is cavernous enough to accommodate an upended double decker bus. Once the top and side hatches are sealed, high-performance pumps create a vacuum a billion times less dense than standard sea-level atmosphere, and this is held for weeks at a time during test runs. A Sun simulator shines intense light on the test item at the same time that liquid nitrogen is pumped through the walls to recreate the cold of space in the shade.