ZenitJul 29, 2023
Mark McCaughrean

A wizard prang 🧙‍♂️🛰️🇦🇶

ESA’s pioneering wind mission, #Aeolus, was guided to a re-entry over Antarctica last night, ensuring that any remaining hardware landed safely in the Atlantic 🌊🌍

This successfully demonstrated new techniques for #SpaceDebris mitigation – kudos to our colleagues at the European Space Operations Centre in Darmstadt 🖖🤘

#SpaceFlight #RocketScience #Astrodon

https://www.esa.int/Applications/Observing_the_Earth/FutureEO/Aeolus/Aeolus_a_historic_end_to_a_trailblazing_mission

Aeolus: a historic end to a trailblazing mission

Surpassing scientific expectations and exceeding its planned life in orbit, the Aeolus wind mission has been hailed as one of ESA’s most successful Earth observation missions. And now, its end will go down in history too, thanks to the ingenuity of the Agency’s mission control team who guided this remarkable satellite down to Earth’s atmosphere for a safe reentry.

Jul 29, 2023 at 9:01amMetatext
Show threadMark McCaughreanJul 29, 2023

p.s. If non-British followers don’t get the “wizard prang” reference, it’s Royal Air Force slang for an extremely well targeted hit, derived from the word “prang”, which means to crash one’s own aircraft.

It’s a nod to my years as a pilot in the RAF & also a bit of a dig at that Guardian headline 🤷‍♂️

Show threadbert hubert 🇺🇦🇪🇺🇺🇦Jul 29, 2023
@markmccaughrean well done! But I’m a bit confused what is so unique about this deorbiting? Is this the first time it happened actively managed? Thanks!
Show threadMark McCaughreanJul 29, 2023
@bert_hubert In a sense, yes. The construction of Aeolus began ~20 years ago, before space debris management was such an issue, & as such, it was never designed to be actively guided to re-entry. So the team used the last kilos of orbit maintenance propellant to guide it as well as possible to a safe entry – that’s a first, I believe. More recent satellites should (but do not always) have deliberate re-entry systems built-in.
Show threadsaarmullerJul 29, 2023
@markmccaughrean @bert_hubert Hi Mark, thank you, I wondered as well. And also, I understood why dumping the remaining propellant would make sense, but as there was not any, why turn Aeolus off?
Show threadMark McCaughreanJul 29, 2023

@saarmuller @bert_hubert Rising upper atmosphere density due to increased solar activity as we move towards solar maximum meant Aeolus would come down in an uncontrolled way anyway. So the team elected to end science ops in April, saving the last drops of propellant to deliberately lower the orbit in a way that Aeolus would re-enter in a semi-controlled, safe way.

https://www.esa.int/Applications/Observing_the_Earth/FutureEO/Aeolus/Trailblazing_Aeolus_mission_winding_down

Trailblazing Aeolus mission winding down

On 30 April 2023, all nominal operations of Aeolus, the first mission to observe Earth’s wind profiles on a global scale, will conclude in preparation for a series of end-of-life activities.