The pressure is on to reduce the amount of greenhouse gases we pump into the atmosphere – but the race is also on to support the monitoring that shows if targets are being met. Being developed by ESA on behalf of the EU, the new Copernicus Anthropogenic Carbon Dioxide Monitoring mission, or CO2M for short, is destined to be Europe’s prime mission for monitoring and tracking carbon dioxide emissions from human activity. CO2M is currently planned as a two-satellite mission, each of which will carry a near-infrared and shortwave-infrared spectrometer to measure atmospheric carbon dioxide at high spatial resolution. Engineers at Thales SESO in France explain how the development of some of the mission’s precision measuring and optical components is going.