Engineers have been at Russia's Plesetsk launch site for a month now, ticking off the jobs on the ‘to do' list so that the Copernicus Sentinel-5P satellite is fit and ready for liftoff on 13 October. With the satellite now fuelled, the team has passed another milestone.

Fuelling a satellite is a particularly delicate operation. Hydrazine is extremely toxic so only a few specialists wearing ‘scape' suits remain in the cleanroom.

Once filled with 82 kg of hydrazine, the satellite was weighed. Permission to fuel came after the Rockot launcher had been tested.