Although this pure gold pin is not much bigger than the tip of a pencil, it is the "pulsing heart" of ESA's Low Earth Orbit Facility, LEOX. Part of the Agency's Materials and Electrical Components Laboratory, based at ESA's ESTEC technical center in the Netherlands, this test facility is vital for developing materials capable of withstanding the highly-erosive individual oxygen atoms prevailing at the top of the atmosphere, the result of standard oxygen molecules of the same kind found just above the ground being broken apart by powerful ultraviolet radiation from the sun.