Arianespace Vega launches long-awaited Aeolus wind-mapping satellite

A European wind-mapping satellite 15 years in the making lifted off Aug. 22 on a Vega rocket from the European spaceport in Kourou, French Guiana.
SpaceNews.com

            WASHINGTON —  A European wind-mapping satellite 15 years in the making lifted off Aug. 22 on a Vega rocket from the European spaceport in Kourou, French Guiana.
Vega launched at 5:21 p.m. Eastern following a one-day delay, due ironically to high-altitude winds, with the European Space Agency’s Aeolus satellite.
Launch provider Arianespace confirmed the 1,360-kilogram satellite contacted ground teams following separation from the rocket’s upper stage. The total mission, including an unexpected 16-minute wait for signal acquisition from the spacecraft, took one hour and 11 minutes.
The launch marks the culmination of many years of work for a mission whose unique laser payload proved extraordinarily difficult to complete. Aeolus is designed to beam ultraviolet radiation through Earth’s atmosphere, detecting backscatter from particles such as dust and water to measure wind. Built by Airbus Defense and Space in the U.K. with two light detection and ranging, or lider, instruments from Selex Galileo of Italy, Aeolus was originally envisioned to launch in 2007, some five years after signing of the manufacturing contract in 2003.
Martin Kaspers, ESA’s head of Earth observation programs, product assurance and safety, said one of the many challenges that added more than a decade to Aeolus’ development was when the primary laser payload (the Atmospheric Laser Doppler Instrument, or Aladin) died immediately during vacuum testing.
“At the beginning, we had a working laser on the table,” Kaspers said in a live, webcasted interview during the launch. “Then we put it in the vacuum chamber and it stopped working.”
Kaspers said the vacuum-induced instrument failure was at the time viewed as a possible death knell for the entire mission, but a fix involving the supply of oxygen to the laser kept Aeolus alive.
Kaspers said the Aeolus team had to build a space-capable oxygenator from scratch with components that could work through extreme differences in pressure.
Another challenge to the Aeolus mission was the discovery that the laser, which fires 50 times a second, would overheat the satellite’s optics. New laser-resistant coatings were developed to withstand the rapid pulses.
“Aeolus carries the first instrument of its kind and uses a completely new approach to measuring the wind from space,” Josef Aschbacher, ESA’s director of Earth observation programs, said in a statement. “Such pioneering technology has meant that it has been a demanding mission to develop, but thanks to all the teams involved we are thrilled that this extraordinary satellite is now in orbit.”
So sensitive are the instruments on Aeolus that ESA and Airbus shipped the satellite from Europe to French Guiana in South America by boat instead of plane to avoid damage from the variations in air pressure that come with flight.
Aeolus is the fifth mission in ESA’s Earth Explorer series, each of which involves the creation of new technologies to tackle Earth science challenges. The satellite is named after the “Keeper of the Winds” in Greek mythology.
Following three months of on-orbit commissioning, Aeolus will begin it’s science mission, which is projected to last three years. It will operate in a 320-kilometer sun-synchronous orbit.
Aeolus is the twelfth Vega mission since the rocket’s 2012 debut, all of which have been successful, and the fifth Arianespace mission of the year. The launch was also Arianespace’s 50th for ESA, and the 72nd ESA satellite to reach space aboard an Arianespace rocket.
SpaceNews.com

Source: Arianespace Vega launches long-awaited Aeolus wind-mapping satellite