Having overcome technical problems that added years to the development of the science payload on the Aeolus satellite, the European Space Agency reports that the Aladin Doppler wind lidar has been successfully integrated with the satellite at Airbus Defence and Space facilities in the UK. The satellite is now heading to France to begin the last round of tests before being shipped to the launch site at the end of 2017 — ten years later than initially scheduled.
Aladin (Atmospheric LAser Doppler INstrument) is equipped with two lasers, a telescope and receivers. The laser generates UV light which is beamed towards Earth. This light bounces off air molecules and small particles such as dust, ice and droplets of water in the atmosphere. The fraction of light that is scattered back towards the satellite is collected by Aladin’s telescope and measured.
The movement of the air molecules, particles or droplets cause this backscattered light to change frequencies slightly. By comparing these frequencies with the original laser, the winds below the satellite can be determined.
The mission will provide accurate and timely profiles of the world’s winds as well as information on aerosols and clouds. These profiles will not only advance understanding of atmospheric dynamics, but will also offer information to improve weather forecasts.
This is a completely new approach to measuring the wind from space, which usually involves tracking cloud movement, measuring the roughness of the sea surface or inferring wind from temperature readings.
Testing in Toulouse will check that the satellite can withstand the vibration and noise of liftoff. Aeolus will then be shipped to Liege in Belgium to be checked in a thermal–vacuum chamber.
Towards the end of the year, the satellite will be shipped across the Atlantic to Europe’s Spaceport in French Guiana for launch on a Vega rocket.