Published on 15 December 2022
It’s another remarkable success for ESA’s fifth Earth Explorer. Launched in 2018 after many technical challenges, Aeolus pioneered what none had pioneered before – directly measuring global wind profiles from space using a laser.
Aeolus’ Aladin laser beams UV light into Earth’s atmosphere and detects the light scattered back from air molecules, water and particles such as dust. A technique known as Doppler wind lidar allows us to calculate wind speed based on the changes in frequency of the backscattered light that returns to the satellite.
In the year following the satellite’s launch, however, jeopardy struck. With the original laser output energy (FM-A) degrading more than foreseen, the mission was forced into an early switch to the backup laser (FM-B).
The second laser has performed admirably, taking Aeolus beyond its predicted lifetime in space. Aeolus has exceeded expectations to deliver wind data of such high quality that it’s now routinely used by weather forecasters worldwide.
Christmas lights shine bright for Aeolus
The satellite’s global coverage meant that, during the 2020 COVID lockdowns when aircraft that would normally provide weather data were grounded, Aeolus managed to chip in with missing measurements. Recent results indicate that Aeolus measurements can also improve models tracking volcanic plumes and tropical cyclones. The overall economic benefits of the mission were calculated as €3.5 billion, a return on investment of more than 7:1.
Three years on, despite increasing the energy of the FM-B laser, the atmospheric return signal – though still providing usable data – was once again deteriorating rapidly.
You’d be forgiven for thinking that this might mean the end for the Aeolus mission, but ESA and industry project teams had other ideas. After two months of tirelessly troubleshooting, tinkering and tailoring, they have managed to eke more life out of the satellite with a switch back to the original FM-A instrument.
Not only that, Aladin is shining brightly again.
European Space Agency (ESA). (2022, December 15). Christmas comes early for Aeolus. Retrieved December 15, 2022, from https://www.esa.int/Applications/Observing_the_Earth/FutureEO/Aeolus/Chr...