Developing new ways of monitoring Earth is always demanding, but ESA's Aeolus mission has faced some particularly difficult technical challenges. However, with the success of intense high-energy tests on its novel laser there is now light at the end of the tunnel for this unique mission.

The Aeolus satellite will carry a single, but complex, instrument that will probe the atmosphere to profile the world's winds. Reliable and timely wind profiles are urgently needed by meteorologists to improve weather forecasts. In the long term, they will also contribute to climate research.

Aeolus carries a pioneering instrument called Aladin that uses laser light scattering and the Doppler effect to gather data on wind.