The European Space Agency (ESA) and Arianespace have signed a contract to secure the launch of the Aeolus satellite, designed to improve scientists’ understanding of Earth’s winds. The contract, worth €32.57m, was signed at ESA headquarters in Paris on 7th September. The satellite, part of the Earth Explorer series, is scheduled to launch on Vega by the end of 2017.
The mission will demonstrate cutting-edge technology that could pave the way for new ways of observing our planet and future applications of Earth observation data.
Aeolus will be the first satellite to provide profiles of the wind on a global scale. To do so it carries one of the most challenging pieces of space technology ever developed: the Aladin wind ‘lidar’ – a laser form of radar.
This state-of-the-art instrument houses two powerful lasers, a large telescope and very sensitive receivers. The laser generates ultraviolet light that 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 reflected back to the satellite is collected by Aladin’s telescope and measured.
The movement of the air molecules, particles or droplets cause this reflected light to change frequency slightly. By comparing the frequencies returned from various altitudes with the original laser, the winds below the satellite can be determined.
Despite numerous setbacks during development, recent tests show that Aladin is now ready for service. Engineers at Airbus Defence and Space in Stevenage, UK, are currently integrating the instrument into the satellite.