DLR's HALO and Falcon measurement aircraft were equipped with highly specialised instruments at the DLR Flight Operations Facility in Oberpfaffenhofen. In the coming weeks, as part of the BLUESKY research campaign, they will measure the concentrations of trace gases and pollutants in the air above European urban areas and in the flight corridor to North America to find out how strong these effects of the Coronavirus lockdown are on the atmosphere.