Aeolus: Cutting Edge Laser Satellite Blasts Off

The Aeolus satellite depicted in space. ESA

The European Space Agency launched a satellite Wednesday that will shoot a laser through space to measure the ripples and flows of Earth's wind in near real time.

Named for Aeolus, the ancient Greek "keeper of the winds," scientists have high expectations for the craft, which—if successful—should vastly improve weather reporting.

Docked on a Vega rocket, the €480 million satellite was set to fly from Kourou, French Guiana, at 6.20 p.m. local time (5.20 p.m. ET) Tuesday 21 August. Ironically, unfavorable weather conditions set the launch back by 24 hours.

The satellite will orbit our planet at an altitude of 200 miles and will travel around our planet in a sun-synchronous loop. From there, it will beam a laser into the atmosphere and measure the signal bouncing back from tiny particles edging through the skies.

The satellite will probe the weather from Earth's surface to a height of 20 miles. This information will help forecasters better understand the speed and direction of wind in almost real-time. Pumping this data into weather models should improve the quality of predictions enormously.

The benefits of accurate forecasts are hard to overestimate. Beyond helping you decide what to wear each day, weather predictions are vital for industries such as farming, shipping, aviation and energy. And when it comes to extreme weather, accurate forecasts save lives.

"By measuring wind better, you also understand the whole functioning of the Earth system better," the European Space Agency's Earth Observation director, Josef Aschbacher said en route to Kourou.

But beset by spiralling costs and more than a decade of delays, it's been a long and frustrating road to get this cutting-edge satellite ready for launch. Perhaps most damning was the discovery that the crucial laser system might not even work in the vacuum of space.

Although the satellite has spent its entire life in clean rooms, some organic matter will still have snuck onboard. Without air, this contamination can carbonize and risk parts of satellite overheating. But the Aeolus team came up with a solution: miniscule puffs of oxygen. "A flow of oxygen [can] disperse [the] fog of molecules coming out of the optical system," Aschbacher explained.

After delays, improvements, and a successful six-month spell in a chamber designed to mimic the effects of space, engineers are finally gearing up for the real thing.

"We had a few tests of the laser before, and they failed, and we have learnt from those tests what needs to be improved," Aschbacher said. "We are confident that it works in space."

This article has been updated to reflect the successful launch of the Aeolus satellite.