British-built Aeolus satellite launches on mission to map the Earth's wind patterns

The satellite lifted off atop a Vega launcher from the European Space Agency (ESA) spaceport in Kourou, French Guyana, last night after delays owing to weather conditions. It will now undergo a series of tests after achieving its orbital altitude of 320km (200 miles) before beginning operations.

Aeolus was built at Airbus Defence and Space's facility in Stevenage. Weighing 1.4 tonnes, its main instrument is a LIDAR called Aladin, which uses a 3.4kW ultraviolet laser to measure wind speed, the first time such an instrument has been used for such measurements.

Aladin relies on the Doppler effect; the laser signal is reflected back to the satellite by particles of dust and moisture droplets entrained in the airstream, and these reflections are detected by a 1.5m diameter telescope. On-board receivers analyse the Doppler shift in the reflected light from various layers of air, which gives an accurate reading of the windspeed. Other British-made systems on board include cameras, software and propulsion systems. Chelmsford-based e2v supplied a unique Charge Coupled Device (CCD) type detector specifically for the mission.