Cleaning Aeolus in the dark with torch

As part of the preparations to launch Aeolus on 21 August, the satellite has been cleaned, centimetre by centimetre. A faint purple light can be seen in the photo, but this is actually a powerful ultraviolet torch the team uses to detect particles of dust. If any particles are found, they are removed with a soft brush and a vacuum cleaner.  This is a bit of a tedious task, but one that is necessary.