NASASpaceFlight.com Forum
Robotic Spacecraft (Astronomy, Planetary, Earth, Solar/Heliophysics) => Space Science Coverage => Topic started by: jacqmans on 05/12/2020 08:17 am
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Aeolus goes public
12/05/2020
Delivering new information about Earth’s winds, ESA’s Aeolus mission has already been hailed a success. Today, this remarkable satellite mission has yet again achieved new heights: its data are now being distributed publicly to forecasting services and scientific users in less than three hours of measurements being made from space.
Aeolus is one of ESA’s Earth Explorer missions, which all set out to demonstrate how new ways of observing Earth can advance our understanding of how the planet works as a system.
Carrying one of the most sophisticated instruments ever to be put into orbit, Aeolus is the first satellite mission to directly profile Earth’s winds from space.
http://www.esa.int/Applications/Observing_the_Earth/Aeolus/Aeolus_goes_public
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Aeolus shines a light on polar vortex
04/02/2021
As this winter’s polar vortex currently sends extreme icy blasts of Arctic weather to some parts of the northern hemisphere such as the northeast of the US, scientists are using wind information from ESA’s Aeolus satellite to shed more light on this complex phenomenon.
The polar vortex is a huge mass of frigid air high above the North Pole in the polar stratosphere. It is surrounded by a strong jet of air swirling counter-clockwise along the vortex’s boundary. The vortex tends to be much stronger in the winter, keeping bitter cold air locked in around the Arctic.
However, sometimes the vortex can weaken, become distorted or even split into two and meander further south, affecting the weather and jetstream further down in the troposphere, potentially bringing unusually cold weather and snow to lower latitudes.
One meteorological event that can disturb the polar vortex is known as a ‘sudden stratospheric warming’, which is what has been happening over the last couple of months. Sudden stratospheric warmings happen to some extent every year, but the current event has been categorised as major, and is less common.
Such dramatic events cause the strong wind around the edge of the polar vortex to weaken or reverse, leading the temperature of the polar stratosphere to rise rapidly by tens of degrees Celsius.
Since these events can trigger extreme weather in Europe and North America, they are of scientific and practical interest. However, the processes involved are not fully understood, and until recently there have been major technical challenges in measuring wind from space, which is needed to measure and monitor such a large-scale event.
Fortunately, scientists now have ESA’s Aeolus satellite at hand to help understand more about why and how the polar vortex is pushed off balance.
Aeolus is the first satellite in orbit to profile directly Earth’s winds from space.
It works by emitting short, powerful pulses of ultraviolet light from a laser and measures the Doppler shift from the very small amount of light that is scattered back to the instrument from molecules and particles to deliver profiles of the horizontal speed of the world’s winds mostly in the east-west direction in the lowermost 26 km of the atmosphere.
Although Aeolus only measures wind in the lower part of the atmosphere, the lower part of the current stratospheric polar vortex jet leaves a signature in the satellite’s data.
Corwin Wright, Royal Society research fellow at the University of Bath in the UK, said, “Changes in the wind structure in a sudden stratospheric warming event have never been observed directly at a global scale before. So far, our understanding of these changes has been developed using point measurements, measurements along localised aircraft flight tracks, through the use of temperature observations, and, primarily, computer models and assimilative analyses.
“However, we can now exploit novel measurements from Aeolus, the first satellite capable of observing winds directly in the upper troposphere and lower stratosphere, to study this process observationally during this current major event.”
Anne Grete Straume, ESA’s Aeolus mission scientist, commented, “We are currently observing a polar vortex event where we see it split into two, with one spinning mass of air over the North Atlantic and one over the North Pacific.
“The split leads to changes in the tropospheric circulation allowing cold air masses from the poles to more easily escape down to lower latitudes. At the moment, parts of North America seem to be experiencing colder weather than Europe, although we have seen events of cold air reaching quite far south in Europe over the past few weeks causing, for example, heavy snowfall in Spain.
“What scientists would also like to understand is whether sudden stratospheric warming events might become more frequent owing to climate change. Also for this, Aeolus wind data will be very important to better understand the mechanisms triggering these weather events.
“It is early days yet to draw any scientific conclusions from our Aeolus data, but work is certainly underway to shed new light on why this seasonal phenomenon can sometimes be extreme – watch this space.”
https://www.esa.int/Applications/Observing_the_Earth/Aeolus/Aeolus_shines_a_light_on_polar_vortex
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Polar vortex 1 December 2020 to 1 February 2021
04/02/2021
Based on data from ESA’s Aeolus wind mission, the image shows how the polar vortex in the lower stratosphere changed between 1 December 2020 and 1 February 2021. The first few plots at the beginning of December show the vortex in a comparatively normal state, but in mid-December patches of blue wind appear, and the wind is going backwards relative to normal conditions.
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Keeper of the winds shines on (https://www.esa.int/Applications/Observing_the_Earth/FutureEO/Aeolus/Keeper_of_the_winds_shines_on)
Launched back in 2018, Aeolus has outlived its 36-month in-orbit design life – but going above and beyond, it continues to deliver excellent data. This shows that there’s life yet in the satellite, meaning ESA’s wind mission is now expected to continue shining a light on the wind for another year.
The future is bright for Doppler wind lidars in space
While Aeolus is set for at least another year, discussions in Taormina inevitably led to potential follow-on missions. “The value of Aeolus is not only scientific, but also economic and societal,” said ESA’s Director of Earth Observation Programmes Simonetta Cheli in her opening address in Taormina. “Following the success of Aeolus and the operational assimilation of data into weather forecast models, it’s clear there is growing support for a follow-on mission.”
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Belated update:
Keeper of the winds shines on: Aeolus satellite continues past design life (https://www.esa.int/Applications/Observing_the_Earth/FutureEO/Aeolus/Keeper_of_the_winds_shines_on) [dated Apr. 26]
Launched back in 2018, Aeolus has outlived its 36-month in-orbit design life – but going above and beyond, it continues to deliver excellent data. This shows that there’s life yet in the satellite, meaning ESA’s wind mission is now expected to continue shining a light on the wind for another year.
<snip>
Earlier this year, scientists working on the Aeolus Data Science Innovation Cluster used the online visualisation tool to track the Hunga Tonga volcanic eruption.
On 15 January 2022, a huge blip, or drop, in the Aeolus signal over the region of the eruption suggested the plume of volcanic ash must have reached an altitude above the range of Aeolus, as shown in the image above. The image below uses data from three days later, from 18 January, and shows how Aeolus could track the volcanic plume widening and spreading westwards over Australia.
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https://www.esa.int/Newsroom/Press_Releases/ESA_highlights_in_2023
Aeolus reentry from space
Date: May-Sep timeframe
ESA’s pioneering ‘wind mission’ Aeolus has reached the end of its service life in orbit. ESA is now studying options for its reentry, with further details to be confirmed during the first quarter of 2023.
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Note to the moderators:
There is another "ESA - Aeolus updates" thread in the Space Science section.
https://forum.nasaspaceflight.com/index.php?topic=50913.0
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https://twitter.com/esa_eo/status/1648287756613820417
We have a big announcement to make⬇️
On 30 April 2023, all nominal operations of @esa_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.
More news here: https://www.esa.int/Applications/Observing_the_Earth/FutureEO/Aeolus/Trailblazing_Aeolus_mission_winding_down
It's been decided that the best plan is to carefully re-enter the satellite back to Earth.
We'll share details on this soon, so stay tuned!
We want to thank the @esa_aeolus user community who has contributed to one of the most successful missions ever flown by ESA.
https://twitter.com/esa_eo/status/1648288289059635202
For all @esa_aeolus data users: Aeolus will provide data as usual up to the end of operations on 30 April 2023. While no new operational data will be gathered after 30 April, the mission's existing data will still be available.
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Aeolus’ fiery demise to set standard for safe reentry
08/05/2023
ESA’s wind mission, Aeolus, will soon be lowered in orbit leading to its fiery reentry and burn-up through Earth’s atmosphere. ESA’s efforts to ensure a safe return go well beyond international standards and place the Agency in the lead for space safety.
Having exceeded its planned life in orbit, the 1360-kg satellite is running out of fuel. Ensuring that enough fuel remains for a few final manoeuvres, ESA’s spacecraft operators will bring Aeolus back towards our planet’s atmosphere for its inevitable demise.
They will aim the mission towards the ocean, further reducing the very small chance that fragments could cause harm should any reach Earth’s surface.
This is the first assisted reentry of its kind and sets a precedent for a responsible approach to reduce the ever-increasing problem of space debris and uncontrolled reentries.
Why is Aeolus coming home?
Launched in 2018, Aeolus has outlived its planned three-year life in space by more than 18 months. During its mission, its trailblazing wind-mapping laser, which at one stage was thought a nigh-impossible feat of engineering, has significantly improved weather forecasts worldwide.
Aeolus has been hailed as one of the most successful missions ever built and flown by ESA. As an Earth Explorer research mission, it was designed to demonstrate new space technology, but it became one of the highest impact-per-observation weather satellites, and its laser is still performing as well as ever.
However, Aeolus’ fuel is now almost depleted and orbiting low, at an altitude of just 320 km, means it is already being caught up by Earth’s wispy atmosphere.
Speeding up Aeolus’ return is the Sun.
Solar flares and coronal mass ejections release matter and radiation, and when this washes past Earth, it increases the density of Earth’s atmosphere. Intense solar activity in recent months means that the satellite has been using even more fuel to remain in orbit. For Aeolus, it’s been like running against the wind.
This is why, after five years of spectacular science, ESA’s wind mission ended operations on 30 April 2023.
Making use of this phase, scientists have put its instrument into a special mode to perform end-of-life activities that will help to prepare the Aeolus-2 follow-on mission, which like a phoenix will emerge from the ashes of its pathfinding predecessor.
Aeolus’ final breaths
Over the next few months, Aeolus will descend naturally from its current altitude of 320 km to 280 km. At this point, spacecraft operators at ESA’s mission control centre, ESOC, in Darmstadt, Germany, will gradually lower it to 150 km above Earth’s surface. The satellite will burn up as it descends to around 80 km.
As populated regions make up a relatively small percentage of Earth’s surface, the chance of a re-entry causing any harm is exceptionally low.
The final date depends on how solar activity speeds up the process, but Aeolus is expected to be no more before the end of August.
Aeolus engineers and industry partners have carefully worked out how to best position Aeolus in Earth’s atmosphere to target open ocean waters upon reentry, hugely reducing the amount of land over which pieces fragments could fall.
ESA’s Aeolus Mission Manager, Tommaso Parrinello, said, “The exact details on the reentry approach and series of manoeuvres and operations, as well as a more detailed timeline will be made public in mid-June.
“For now, we can anticipate that we are targeting the best ocean corridor to reenter.”
With the assisted reentry of Aeolus, ESA is clearing the way for future missions to continue taking the pulse of our planet. They can only do this if Earth’s orbits aren’t filled with dangerous space debris, and safety is at the forefront of end-of-life activities.
https://www.esa.int/Applications/Observing_the_Earth/FutureEO/Aeolus/Aeolus_fiery_demise_to_set_standard_for_safe_reentry
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Key stages in Aeolus’ reentry
In orbit for almost five years, ESA’s Aeolus wind mission has exceeded its design life. The satellite’s remarkable Aladin instrument beamed down seven billion pulses of UV light to profile Earth’s wind. Aeolus was never designed for a controlled reentry, but ESA is going above and beyond by attempting an assisted reentry – the first of its kind – to make the procedure even safer.
Gravity and the grasping wisps of Earth’s atmosphere as well as solar activity are dragging Aeolus down from its operational altitude of 320 km. Once Aeolus reaches 280 km, a series of commands will use the satellite’s remaining fuel to guide it towards the optimal position for reentry.
A first manoeuvre will lower the satellite to an altitude of 250 km. Four manoeuvres then usher Aeolus down to 150 km. Then the vast majority of the satellite will burn up in Earth’s atmosphere. However, some pieces of debris might reach Earth. Many months of expertise have gone into planning the optimal location for reentry to minimise the already extremely remote possibility that falling debris could pose a risk to life or infrastructure. The flight control team is aiming at a stretch of ocean beneath the satellite’s track – a long stretch of open water as far away from land as possible.
If this assisted reentry attempt has to be aborted, which could still happen, Aeolus’ natural reentry continues.
Related article: Guiding Aeolus' safe reentry (https://www.esa.int/Applications/Observing_the_Earth/FutureEO/Aeolus/Guiding_Aeolus_safe_reentry)
https://www.esa.int/Applications/Observing_the_Earth/FutureEO/Aeolus/Guiding_Aeolus_safe_reentry
Image credit: ESA
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https://www.esa.int/Enabling_Support/Operations/Simulating_Aeolus_s_return_mission_control_feels_the_heat
Simulating Aeolus’s return: mission control feels the heat
18/07/2023
In brief
In a first at ESA’s Main Control Room in Germany, simulations are underway as teams prepare not for a launch, but a satellite’s assisted return through Earth’s atmosphere. Mission successful, fuel running out, Aeolus is now naturally descending. The Flight Control Team at mission control will soon command the wind-mapping satellite for the last time, targeting its reentry towards the ocean to reduce the already very small risk from its return. In simulations, however, things aren’t going to plan.
In-depth
No two missions are the same but launches have many milestones and features in common with each other: a satellite or spacecraft is launched on a gravity-defying rocket into space, after it separates and, exact sequences differ but it is woken up, solar arrays are deployed, instruments are switched on and tested and its thrusters are fired to get it where it needs to be.
Five years ago, Aeolus was doing just this. Now, mission complete, it’s days away from reentering through Earth’s atmosphere, and although it wasn’t designed for this, teams will be attempting to steer it on its path.
Aeolus was planned and built before current international regulations were put in place on end-of-life disposal, but ESA is nonetheless doing all it can to bring Aeolus, retrospectively, in line with the best standards of today. It’s the first time such an assisted reentry is being attempted by ESA’s mission control, but simulations are ongoing to make sure nothing comes as a surprise.
Simulating an assisted reentry: an ESA first
How do you simulate something you’ve never done before? That’s the question for Simulation Officer Filipe Metelo:
“First, we create a realistic simulation of the behaviour we expect from Aeolus as it returns, using the information we have from past reentry scenarios, controlled and uncontrolled, with tried and tested ‘telecommands’ and with various software already available to us,” explains Filipe.
“Then we chose specific scenarios that could happen, both likely and unlikely, and play these out in the Main Control Room. With a ‘pretend’ Aeolus and ground system, it feels to our teams just like the real thing.”
In general, the real operations shouldn’t be so different from the simulated events now being rehearsed, but this reentry comes with greater uncertainty than the launches and manoeuvres commonplace in this historic room.
Current high levels of solar activity, for one thing, are creating unpredictable fluctuations in the thickness of the atmosphere, speeding up Aeolus’ return. As such, aspects of this campaign are being continually adjusted as critical operations near.
Milestone manoeuvres
The key moments in Aeolus’s return will be a series of never-before-performed manoeuvres that should steer Aeolus on a return path over the most uninhabited regions possible, i.e. the ocean.
In case something doesn’t go to plan with any of the manoeuvres, it will be up to the various ground stations around the world to keep track of Aeolus’ signal, then for ESA’s flight dynamics experts to determine its orbit and potentially produce new commands for the Flight Control Team to send up to the satellite.
Five simulations are planned altogether that are more like rehearsals with minor issues surfacing, such as losing contact with Aeolus or parts of the spacecraft reaching unexpected temperatures, than the doomsday scenarios often thrown at teams before a launch.
“If any serious failures occur during the operations, the attempt will be aborted,” explains Isabel Rojo, Flight Operations Director for the mission.
“This was a very intentional decision. Our aim here is to make the situation better than it would otherwise be, to reduce further the already small risk that Aeolus could do any harm in its final moments. We have an ambitious, complex plan, but if it doesn’t work, we default to the status quo: our satellite will reenter naturally.”
Satellites and rocket bodies fall back to Earth on average once per week, and to date have caused no harm. As the number of satellites launched rapidly increases, however, it’s vital that these reentries are as safe as they can possibly be.
What makes this reentry so special, and new, is that it takes a mission built with one ending in mind and, from the ground, is altering its future.
“I’ve probably taken part in more than 60 simulations over my career, but this one is extremely different as we work to execute the planned operations as accurately and safely as possible but with a number of unknowns that are outside of our control,” continues Isabel.
“I’m looking forward to uplinking the last set of commands that will execute Aeolus’ final manoeuvre, and seeing them onboard a spacecraft behaving nominally. Once that is done, our part will be over and can only hope for the best. I am of course nervous about seeing this all go to plan, and any reentering fragments ending up safely in the ocean.”
An unexpected end to the impossible mission
Aeolus Mission Manager Tommaso Parrinello, normally based at ESA’s Earth Observation heart at ESRIN, Italy, has been taking part in the simulations at mission control. Since just after Aeolus was launched, he has straddled the two worlds of Science and Operations and seen not just how challenging this mission has been to fly, but exactly why it’s been so worth it:
“Aeolus is a magical machine that has surprised even the most experienced engineers across the world,” concludes Tommaso.
“Daily, we faced and resolved many technical and scientific challenges to make sure that we could deliver the best data to the meteorological community. But it’s been hard because it’s been new: Aeolus was always meant to be a demonstrator mission, nothing like it had ever been launched into space.”
And just as Aeolus went above and beyond during its mission, revolutionising wind profiling and improving weather models forever, its demise is now also proving to be a challenge of great importance.
“It is only now that you realise that an idea that was proposed just a year ago has become something that is real and tangible. We all know that this reentry is not going to be easy and we might not succeed. Probably, this is the biggest challenge of our professional life, but I could not imagine a different end for this “impossible mission”".
“Listening to the different voice loops and being part of the intertwined activities in the Main Control Room is really a “wow” moment. It’s difficult to describe. Not only is this real, but it is coming fast. We’ve never been readier than we are now!”
Image captions:
Measuring cyclones
Filipe Metelo and Isabel Rojo during Aeolus reentry simulations. Simulation Officer Filipe says "for the teams, these simulations feel like the real thing"
ESA's Kiruna ground station will be in touch with Aeolus during critical reentry manoeuvres
Illustration depicting the reentry and break up of ESA's Automated Transfer Vehicle resupply spacecraft during a controlled reentry
Isabel Rojo is Aeolus Flight Operations Director
Aeolus: ESA's wind mission
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https://twitter.com/esa_aeolus/status/1681611112872132608
🌠 Aeolus is coming home. But when and where?
🕹️ When: The reentry is scheduled for Friday 28 July, when a final command will guide Aeolus home.
🌐 Where: a long stretch of the Atlantic ocean as far away from land as possible.
👉
https://blogs.esa.int/rocketscience/2023/07/19/aeolus-assisted-reentry-when-and-where/
AEOLUS ASSISTED REENTRY: WHEN AND WHERE
19/07/2023
ESA’s keeper of the winds is coming home.
After completing its mission, Aeolus has been falling from its operational altitude of 320 km since 19 June.
Operators at ESA mission control in Germany have been keeping a close eye on Aeolus. As soon as it reaches 280 km on Monday 24 July, using the last of Aeolus’ fuel, the first of several critical manoeuvres will be performed to steer ESA’s wind satellite slowly back to Earth.
The final manoeuvre is scheduled for Friday 28 July, when a final command will guide Aeolus home from an altitude of 150 km to just 120 km. Then, the satellite will reenter.
At around 80 km, most of the satellite will burn up, but a few fragments may reach Earth’s surface.
WHERE WILL AEOLUS REENTER?
Mission scientists and engineers have worked tirelessly to calculate the optimal orbit for Aeolus to reenter Earth, which targets a remote stretch of the Atlantic ocean.
The general risk from reentering satellites is already very low. For example, the risk of an individual being hit by a piece of space debris is approximately three times lower than the risk from a falling meteorite.
By targeting the Atlantic ocean, which offers the best satellite visibility during the critical final reentry phases, the assisted reentry will further reduce this risk by 42 times.
The pioneering attempt to assist Aeolus’ reentry is a complex and novel task. It might not work. However, if at any stage the attempt must be aborted, Aeolus will reenter naturally as originally planned.
Successful or not, the attempt paves the way for the safe return of active satellites that were never designed for controlled reentry.
Image caption:
The key stages of Aeolus’ reentry. Credit: ESA/Earth Observation Graphics Bureau
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https://www.youtube.com/watch?v=9pJ7liC5q3g
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https://twitter.com/esaoperations/status/1683561138317828096
#Aeolus reentry #operations, day 1: first manoeuvre successfully completed!
Today saw the largest thruster firing in #Aeolus’s five years in orbit:
📏Altitude lowered by ~ 30 km
⏲️Burn duration: 37 min 24 secs
⛽️Fuel consumption: ~ 6 kg
Find out more🛰️👉 https://blogs.esa.int/rocketscience/2023/07/24/aeolus-reentry-live/
Remember, Aeolus was not designed for this ending. It was ‘meant’ to naturally fall in an uncontrolled reentry – its propulsion system and fuel reserves were not designed to allow the satellite to be controlled down to the required altitudes for a fully controlled reentry.
https://twitter.com/esaoperations/status/1683561805430374402
With this campaign, ESA engineers and operators are pushing the satellite to the limits of what it can do.
The success of this first manoeuvre bodes well for the rest of the campaign.
#ByeByeAeolus👋🛰️
#SustainableSpace♻️
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Related video:
https://youtu.be/f1FKeqJVvXI
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https://twitter.com/esaoperations/status/1683874962917011464
#Aeolus reentry #operations, day 2: between manoeuvres
Today and tomorrow were set aside in the reentry planning, in case anything unexpected happened during yesterday's first, and huge, manoeuvre.
That having gone well, teams today prepare for the next👉 https://blogs.esa.int/rocketscience/2023/07/24/aeolus-reentry-live/
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https://twitter.com/esaoperations/status/1684225526422970371
#Aeolus reentry: a breakdown
Check out this animation showing the key stages in Aeolus' first-of-its-kind assisted reentry.
From 'slews' to thruster burns to satellite commands, this is our plan, happening now, to guide @ESA_Aeolus's descent 🕹️🛰️👇🔥👉esa.int/ESA_Multimedia…
https://youtu.be/KzDy_hQDztA
Phase I: @ESA_Aeolus naturally descended to 280 km from its operational orbit of 320 km.
The satellite has been fighting Earth's gravity and atmosphere throughout its life in low-Earth orbit, bumped up routinely by teams at ESA #MissionControl
#ByeByeAeolus👋
https://twitter.com/esaoperations/status/1684227634840866818
At which point, on Monday this week, the first manoeuvres were executed to turn @ESA_Aeolus's 'uncontrolled' reentry into a 'semicontrolled' one, using ~6 kg of saved fuel to check all systems are GO and bring the satellite down to 250 km 👉twitter.com/esaoperations/…
#ByeByeAeolus
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https://twitter.com/esa_aeolus/status/1684597415070887937
✅ First manoeuvre of the day
✅ A fantastic team
✅ Ready to go for the next ones
📒 Keep following here, @esaoperations, and the #RocketScience blog for more
🚀 https://blogs.esa.int/rocketscience/2023/07/24/aeolus-reentry-live/
https://twitter.com/esaoperations/status/1684601040824311808
And now we have the numbers for manoeuvre #1/4
🟩Manoeuvre #1: success!
⏳Burn duration: 45 minutes
⛽️Fuel used: 6 kg
📏Aeolus altitude: from 250 to 230 km
Thanks team. On to the next.
#ByeByeAeolus
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https://twitter.com/esaoperations/status/1684849560575754240
Aeolus reentry update🚨✅
Phase II of the assisted reentry is complete! 4 burns successfully fired last night and well into the morning.
But, at these low altitudes, it wasn't all smooth sailing. More info 🌬️🛰️👉
https://blogs.esa.int/rocketscience/2023/07/24/aeolus-reentry-live/
Day 5: catch up on Phase II, final GO/NO-GO checkpoint for Phase III
28 July 2023, 10:47 CEST
Good morning! While we slept, the Mission Control Team kept on flying.
The very good news is that all four manoeuvres of Phase II were successfully executed! They began yesterday afternoon and continued through the night and well into the early morning.
Following last night’s burns, Aeolus is already skimming the top of our atmosphere, already being buffeted by denser air – our planet’s protective shield – in a preview of what’s to come tonight. Aeolus is now sailing at an altitude below 160 km.
But, it wasn’t all smooth sailing.
There was a moment when the words “major anomaly” rang out over the voice loop, and the team came together in the Briefing Room to discuss what at first looked like an issue with the thrusters that could mean the rest of the assisted reentry attempt would have to be aborted.
The team really had to make decisions fast. “Five minutes til AOS” said Flight Operations Director Isabel Rojo, and the team got back into the Main Control Room, got back in touch with the mission, and not long later calm resumed in the ‘MCR’ and reassuring bright green lights again shone on.
What happened? Aeolus wasn’t meant to be manoeuvred at such low altitudes, and flying through this part of the atmosphere is extremely challenging. Already, the satellite is feeling the pressure.
Once this critical phase is over, there will be time to delve into what exactly happened and apply lessons to future similar assisted reentries, that could become more common as a result of this first-of-its-kind attempt.
Teams have already begun flying Aeolus in a new way, pointing the spacecraft into the oncoming ‘wind’ to keep it stable in the last hours of its pioneering life.
Preparations are now underway for the next, and final, GO/NO GO checkpoint later, and if all is GO we look forward to the final manoeuvre.
Stay tuned.
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https://twitter.com/esaoperations/status/1684892994678218752
Final checkpoint: we are GO for Phase III!✅
Soon, the very last commands will be sent to @ESA_Aeolus🕹️. In a final thruster burn, the pioneering Earth Observer comes home.
It's bittersweet for all involved, but a fitting end for a revolutionary mission👉
https://blogs.esa.int/rocketscience/2023/07/24/aeolus-reentry-live/
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https://twitter.com/esaoperations/status/1684945807839993857
The final manoeuvre has begun for @ESA_Aeolus, and so far all is looking nominal.
Aeolus is coming home.
#ByeByeAeolus👋🛰️🥹
https://twitter.com/esaoperations/status/1684950393652928512
The #MissionControl Team has done everything they planned, @ESA_Aeolus is now out of their hands.
From skilled engineers to wonderful wizards in the flight dynamics team, it's a proud moment in the Main Control Room.
They now hand over to our #SpaceDebris experts. #ByeByeAeolus
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twitter.com/esaoperations/status/1684966671159631875
News just in: @ESA_Aeolus has been spotted by the TIRA radar in Germany, @Fraunhofer_FHR📡
As we put @ESA_Aeolus to sleep, we can't hear from our Earth Explorer. We rely on ground observations to follow its last moments.
Our #SpaceDebris experts are analysing the data ...
Edit to add:
https://twitter.com/esaoperations/status/1684972294173597703
🔥✅Data from the TIRA radar has been analysed, and shows that Aeolus was found almost exactly where it was expected, confirming a successful final manoeuvre!🔥✅
#ByeByeAeolus👋🥹🛰️
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https://twitter.com/esaoperations/status/1685001869825851392
According to our calculations, @ESA_Aeolus should now have reentered Earth's atmosphere🔥🪦
We're waiting for confirmation from our partners with information on the exact time and location of entry🗺️
#ByeByeAeolus🥹
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https://twitter.com/esa_aeolus/status/1685183480781561856
🌠🎯🇦🇶 CONFIRMED in the early hours, #Aeolus reentered Earth’s atmosphere on 28 July at around 21:00 CEST above Antarctica.
✅ by US Space Command.
Read more about the historic, pioneering end to a trailblazing mission👉esa.int/Applications/O…
#ByeByeAeolus
#SustainableSpace
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https://twitter.com/esa_aeolus/status/1685183480781561856
🌠🎯🇦🇶 CONFIRMED in the early hours, #Aeolus reentered Earth’s atmosphere on 28 July at around 21:00 CEST above Antarctica.
✅ by US Space Command.
Read more about the historic, pioneering end to a trailblazing mission👉esa.int/Applications/O…
#ByeByeAeolus
#SustainableSpace
Firstly congratulations to all of the Aeolus team for this very successful pioneering mission to fly a UV LIDAR, then bring it down in a controlled manner.
The data they have produced has significantly
a) Updated the global climate models. So in its absence numerical weather forecasters can substitute a better model for wind speeds and directions. Including (perhaps) enough improvements to maintain the predicted 9% improvement in predicting the paths of Catagory 5 storms, something that can save 100s (1000s?) of lives and reduce property damage.
b) Generated lots of "lessons learned" for future UV LIDAR construction. AIUI a big problem was laser induced contamination/damage.
Both were caused by the use of porus optical coatings. When the coatings outgassed they became much more easily damaged by the lasers and the gases smeared onto the rest of the optics, cutting transmission, a classic "double whammy." :( . Bleeding 02 into the optical system seems to have been used as a getter. Recognition that porus coatings, and the development of less porus ones, is the ultimate answer of course.
Keep in mind Aeolus was a demonstrator mission, effectively an X programme. It's design is more than 20 years old when a 355nm laser meant feeding the output of an Nd:YAG into a frequency tripling crystal system. Today UV laser diodes are COTS parts.
I look forward to the next generation UV LIDAR orbiting ASAP.
A Mars version of Aeolus (also called Aeolus) is targetting 3 sensors in a 40Kg package but with wind cells 10Km in height. On that basis could a version of Aeolus II be done as (say) a 3U cubesat?
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https://youtu.be/KzDy_hQDztA
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https://twitter.com/esaoperations/status/1687014779838185472
Simulating Aeolus’s demise: a bird’s eye view🛰️🔥🪦👉https://www.esa.int/ESA_Multimedia/Videos/2023/08/Simulating_Aeolus_s_demise_a_bird_s_eye_view
#ByeByeAeolus
#SustainableSpace
https://youtu.be/0huyyQLVpwM
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https://twitter.com/esaoperations/status/1687405050031636480
Here we have it: our assessment of where @ESA_Aeolus finally reentered Earth's atmosphere and location where any fragments may have fallen.
It wasn't easy to pinpoint as no one was around to witness it. That's exactly what we wanted.
More👉https://www.esa.int/ESA_Multimedia/Images/2023/08/Right_on_track_Aeolus_reentry_map
#ByeByeAeolus