{"id":2103,"date":"2023-08-01T17:32:07","date_gmt":"2023-08-01T17:32:07","guid":{"rendered":"https:\/\/www.spacepreneurmag.com\/?p=2103"},"modified":"2023-08-01T17:32:08","modified_gmt":"2023-08-01T17:32:08","slug":"simulating-aeoluss-return-mission-control-feels-the-heat","status":"publish","type":"post","link":"https:\/\/www.spacepreneurmag.com\/index.php\/2023\/08\/01\/simulating-aeoluss-return-mission-control-feels-the-heat\/","title":{"rendered":"Simulating Aeolus’s Return: Mission Control Feels the Heat"},"content":{"rendered":"\n

In brief<\/strong>
In a first at ESA\u2019s Main Control Room in Germany, simulations are under way as teams prepare not for a launch, but a satellite\u2019s assisted return through Earth\u2019s atmosphere. Mission successful, fuel running out, Aeolus is now naturally descending.<\/p>\n\n\n\n

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\u2019t going to plan.<\/p>\n\n\n\n

In-depth<\/strong>
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.<\/p>\n\n\n\n

Five years ago, Aeolus was doing just this. Now, mission complete, it\u2019s days away from reentering through Earth\u2019s atmosphere, and although it wasn\u2019t designed for this, teams will be attempting to steer it on its path.<\/p>\n\n\n\n

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\u2019s the first time such an assisted reentry is being attempted by ESA\u2019s mission control, but simulations are ongoing to make sure nothing comes as a surprise.<\/p>\n\n\n\n

Simulating an assisted reentry: an ESA first<\/strong>
How do you simulate something you\u2019ve never done before? That\u2019s the question for Simulation Officer Filipe Metelo:<\/p>\n\n\n\n

\u201cFirst, 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 \u2018telecommands\u2019 and with various software already available to us,\u201d explains Filipe.<\/p>\n\n\n\n

\u201cThen we chose specific scenarios that could happen, both likely and unlikely, and play these out in the Main Control Room. With a \u2018pretend\u2019 Aeolus and ground system, it feels to our teams just like the real thing.\u201d<\/p>\n\n\n\n

In general, the real operations shouldn\u2019t 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.<\/p>\n\n\n\n

Current high levels of solar activity, for one thing, are creating unpredictable fluctuations in the thickness of the atmosphere, speeding up Aeolus\u2019s return. As such, aspects of this campaign are being continually adjusted as critical operations near.<\/p>\n\n\n\n

Milestone manoeuvres<\/strong>
The key moments in Aeolus\u2019s 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.<\/p>\n\n\n\n

In case something doesn\u2019t 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\u2019s signal, then for ESA\u2019s flight dynamics experts to determine its orbit and potentially produce new commands for the Flight Control Team to send up to the satellite.<\/p>\n\n\n\n

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.<\/p>\n\n\n\n

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.<\/p>\n\n\n\n

\u201cI\u2019ve 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,\u201d continues Isabel.<\/p>\n\n\n\n

\u201cI\u2019m looking forward to uplinking the last set of commands that will execute Aeolus\u2019s 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.\u201d<\/p>\n\n\n\n

An unexpected end to the impossible mission<\/strong>
Aeolus Mission Manager Tommaso Parrinello, normally based at ESA\u2019s 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\u2019s been so worth it:<\/p>\n\n\n\n

\u201cAeolus is a magical machine that has surprised even the most experienced engineers across the world,\u201d concludes Tommaso.<\/p>\n\n\n\n

\u201cDaily, 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\u2019s been hard because it\u2019s been new: Aeolus was always meant to be a demonstrator mission, nothing like it had ever been launched into space.\u201d<\/p>\n\n\n\n

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.<\/p>\n\n\n\n

\u201cIt 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 \u201cimpossible mission\u201d”.<\/p>\n\n\n\n

\u201cListening to the different voice loops and being part of the intertwined activities in the Main Control Room is really a \u201cwow\u201d moment. It\u2019s difficult to describe. Not only is this real, but it is coming fast. We\u2019ve never been readier than we are<\/p>\n","protected":false},"excerpt":{"rendered":"

In briefIn a first at ESA\u2019s Main Control Room in Germany, simulations are under…<\/p>\n","protected":false},"author":1,"featured_media":2114,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[102],"tags":[219,210,211,215,214],"class_list":["post-2103","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-space-news","tag-indian-space-magazines","tag-indian-space-news","tag-space-magazines","tag-space-news-online","tag-space-news-today"],"_links":{"self":[{"href":"https:\/\/www.spacepreneurmag.com\/index.php\/wp-json\/wp\/v2\/posts\/2103","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.spacepreneurmag.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.spacepreneurmag.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.spacepreneurmag.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.spacepreneurmag.com\/index.php\/wp-json\/wp\/v2\/comments?post=2103"}],"version-history":[{"count":1,"href":"https:\/\/www.spacepreneurmag.com\/index.php\/wp-json\/wp\/v2\/posts\/2103\/revisions"}],"predecessor-version":[{"id":2115,"href":"https:\/\/www.spacepreneurmag.com\/index.php\/wp-json\/wp\/v2\/posts\/2103\/revisions\/2115"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.spacepreneurmag.com\/index.php\/wp-json\/wp\/v2\/media\/2114"}],"wp:attachment":[{"href":"https:\/\/www.spacepreneurmag.com\/index.php\/wp-json\/wp\/v2\/media?parent=2103"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.spacepreneurmag.com\/index.php\/wp-json\/wp\/v2\/categories?post=2103"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.spacepreneurmag.com\/index.php\/wp-json\/wp\/v2\/tags?post=2103"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}