Europe launched a rocket from French Guiana on Wednesday to bring a satellite into orbit around the globe as part of what Arianespace called the world's first space mission to map the wind on a global scale.
The launch took place at 21.20 GMT after a 24-hour delay due to adverse weather conditions. The flight was planned at just under 55 minutes from the launch until the separation of the satellite.
The satellite – named Aeolus after the guardian of the wind in Greek mythology – will be placed at an altitude of 320 km above the earth.
It is part of the Copernicus project, a joint initiative of the European Union and the European Space Agency (ESA) to monitor environmental damage and support disaster relief operations.
Aeolus is equipped with a single instrument: a Doppler windlidar – an advanced laser system designed to accurately measure global wind patterns from space.
"This mission will provide much-needed data to improve the quality of weather forecasts and contribute to long-term climate research," Arianespace said on its website.
Especially tropical winds are very badly mapped because of the almost complete absence of direct observations.
The Doppler lidar emits short, powerful pulses of laser light to the earth in the ultraviolet spectrum. Particles in the air – moisture, dust, gases – disperse a small part of that light energy back to the transceiver, where it is collected and recorded.
The delay between the outgoing pulse and the so-called "backscattered" signal reveals the direction, speed and distance traveled by the wind.
Once per orbit, data is downloaded to a ground station in Svalbard, Norway.
Aeolus is the fifth of Earth's planned Earth Explorer missions.
Others who are already finished or in operation have measured the gravity and geomagnetic fields of the earth, soil moisture, salinity of the ocean and frozen plains that are collectively known as the cryosphere. The new mission is also Arianespace's 50th launch for the ESA.