Sentinel-5 is a Copernicus mission that will be carried on the MetOp Second Generation A-type weather satellites. Delivering important data on the composition of the atmosphere, the Copernicus Sentinel-5 mission is set to make a step change in monitoring and forecasting global air quality. It will measure the distribution of atmospheric trace gases such as ozone, nitrogen dioxide, sulphur dioxide, formaldehyde, glyoxal, carbon monoxide, and methane, as well as aerosols. These gases can not only affect the air we breathe, but also our climate.