Aeolus orbited the Earth for four years, eleven months and six days. In the end, three hours was, for a very short time, space junk. This new animation was created from the last eight images taken by ESA’s Wind Profiler mission, showing how it began to drop when struck by Earth’s atmosphere during a very brief “debris” phase.

International rules to prevent space debris from forming set a limit on how long a satellite must remain in orbit after completing its mission; this period should not exceed 25 years.

In low-altitude missions, their return is faster because they are captured by Earth’s transparent atmosphere and return home quickly.

During Aeolus’ first assisted entry in July, not only was the (already low) risk of falling debris reduced by a factor of 150, but the time that Aeolus remained in uncontrolled orbit was reduced by several weeks. This vital limits the risk of collisions with other satellites on its way through space.

touching moments

Aeolus was wrecked after the last command was executed at 17:43 on 28 July 2023; after that, the flight control crew could no longer talk to, hear, or affect the satellite. After months of preparation and a week of intense and critical operations, the crew did their best, the satellite was deactivated, shut down and “delivered” to ESA’s Space Debris Office, which watched its final landing.

Looking at the ground track (see map below), which is the way Aeolus likely flew over Earth, it was clear that the Tracking and Imaging Radar (TIRA) at Fraunhofer FHR in Germany would get a good picture. Using its 34-metre antenna, TIRA followed Aeolus for about four minutes at approximately 6:20 PM CEST.

Aeolus returned to Antarctica at 20:40-42 CEST on July 28, 2023. By converting Aeolus’ natural uncontrolled entry into an auxiliary entrance and choosing the best re-entry trajectory, the already very small risk of surviving fragments falling near settlements was further reduced by a factor of 150. Copyright: ESA

Observation of spacecraft and final return

“Spacecraft operators are accustomed to dialogue about their missions, but debris cannot talk. These recent observations confirm that Aeolus’ afterburning is going well and that the now ‘dead’ satellite has entered the expected elliptical orbit at a minimum altitude of 120km,” explains ESA’s Spacecraft operators. Office of the Wreckage expert Benjamin Bastida Virgili.

“If you think of the path of Aeolus as a slightly squashed circle rather than a line, the circle got smaller and rounder as it turned, but its height still increased and decreased. We used this orbital information to calculate a new estimate of the time of Aeolus re-entry two hours later and on its planned path.”

This was the last time the mission teams saw Aeolus. This still intact object disintegrated in Earth’s atmosphere over Antarctica, away from inhabited areas, in just two hours. Around 20:40 CEST, Aeolus turned into a fireball (a temporary shooting star in the atmosphere) for about two minutes.

“Usually, when a mission enters the nose of the rocket and the coating around it is closed, this is the last moment we expect to see it,” says Tommaso Parrinello, Aeolus mission manager.

“With Aeolus, a great example of sustainable spaceflight and responsible operations, we stayed on the mission for as long as possible, managed its return as best we could, and these images are our final farewell to a mission we all miss but whose legacy lives on.” Source