Aerodynamic Behavior of a Descending Launcher First Stage Demonstrator with Grid Fins in the Aerodynamic Phase

Aerodynamic Behavior of a Descending Launcher First Stage Demonstrator with Grid Fins in the Aerodynamic Phase | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Aerodynamic Behavior of a Descending Launcher First Stage Demonstrator with Grid Fins in the Aerodynamic Phase Ansgar Marwege, Junnai Zhai, Josef Klevanski, Ali Guelhan This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8914583/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract In the Horizon Europe Project SALTO, a demonstrator of a vertically landing first stage with three Prometheus engines was investigated, the so-called T3. It shall be recovered with a downrange landing approach. In this paper the aerodynamic phase of the descent trajectory was investigated using wind tunnel experiments of the full launcher configuration in the Trisonic Wind Tunnel Cologne (TMK). The grid fins showed to be efficient to trim and control the vehicle. Increasing the size of the grid fins by 10% does not directly transfer into a larger trimmability region. Modelling of the engine nozzles with closed surfaces is acceptable for low fidelity databases but introduces slight deviations with respect to modelling them as open cavities. A Reynolds number variation showed a small effect of the Reynolds number on the force and moment coefficients. A superposition approach defined in earlier work was validated with the wind tunnel data. In the ascent configuration the deployed grid fins mainly generate additional axial force but do not alter the pitch moment substantially. SALTO Grid Fins Aerodynamic Phase Wind Tunnel Experiments Vertical Landing Launcher Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 14 Apr, 2026 Reviewers invited by journal 25 Feb, 2026 Editor assigned by journal 22 Feb, 2026 Submission checks completed at journal 19 Feb, 2026 First submitted to journal 19 Feb, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8914583","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":598188334,"identity":"87566ede-b523-4703-b52b-507fb4bdace0","order_by":0,"name":"Ansgar Marwege","email":"","orcid":"","institution":"German Aerospace Center","correspondingAuthor":false,"prefix":"","firstName":"Ansgar","middleName":"","lastName":"Marwege","suffix":""},{"id":598188335,"identity":"4378a68f-0d7b-4b5b-b95b-26b2bbe12f84","order_by":1,"name":"Junnai Zhai","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2ElEQVRIie3OMQrCMBTG8VeEdgkFt4aKZ/hcKoKHSScXFcHFTUXI5AEcepiCYJeCqyJou2dwdHAwVXFsOjrkP4QE8uM9IpvtD/NW1Qlagpx1wWb6kRqI8yUtTTZgaEyoIuQGzchucigeM3L73l4uFK7kZysTmY56WxAbbGN5TjAnnhvGOLtxVO0TII3lhUEQTsJM+BMEHEs5f5NbUU/amoR6isAplq3PlHpBIVNR2EGgSbnhCQTjuWEx39OLqedwieOovKuF6PpZahjzKfjdWKP/NpvNZqvvBTrcPxcKATXlAAAAAElFTkSuQmCC","orcid":"","institution":"German Aerospace Center","correspondingAuthor":true,"prefix":"","firstName":"Junnai","middleName":"","lastName":"Zhai","suffix":""},{"id":598188336,"identity":"edb01f0a-9486-4975-b557-98d1ab723ee4","order_by":2,"name":"Josef Klevanski","email":"","orcid":"","institution":"German Aerospace Center","correspondingAuthor":false,"prefix":"","firstName":"Josef","middleName":"","lastName":"Klevanski","suffix":""},{"id":598188337,"identity":"5f664697-a3f1-4492-bb8d-753a7fdbcc69","order_by":3,"name":"Ali Guelhan","email":"","orcid":"","institution":"German Aerospace Center","correspondingAuthor":false,"prefix":"","firstName":"Ali","middleName":"","lastName":"Guelhan","suffix":""}],"badges":[],"createdAt":"2026-02-19 06:38:33","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8914583/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8914583/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104399861,"identity":"eb052183-878d-49fe-9803-e6472e6ae785","added_by":"auto","created_at":"2026-03-11 12:07:53","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":8290517,"visible":true,"origin":"","legend":"","description":"","filename":"SALTOCEASForceandMomentsMeasurements260214.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8914583/v1_covered_31e49bc0-69f6-49b3-98b4-9f2aee734fed.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Aerodynamic Behavior of a Descending Launcher First Stage Demonstrator with Grid Fins in the Aerodynamic Phase","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"ceas-space-journal","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ceas","sideBox":"Learn more about [CEAS Space Journal](http://link.springer.com/journal/12567)","snPcode":"12567","submissionUrl":"https://submission.nature.com/new-submission/12567/3","title":"CEAS Space Journal","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"SALTO, Grid Fins, Aerodynamic Phase, Wind Tunnel Experiments, Vertical Landing, Launcher","lastPublishedDoi":"10.21203/rs.3.rs-8914583/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8914583/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn the Horizon Europe Project SALTO, a demonstrator of a vertically landing first stage with three Prometheus engines was investigated, the so-called T3. 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