DLR Teams with 5 European Companies to Develop Reusable Launch Vehicles
conceptual sketch of RETALT1 (Credit: DLR)
COLOGNE, Germany (DLR PR) — The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) and five European companies have teamed up in the RETro Propulsion Assisted Landing Technologies (RETALT) project to jointly advance the research and development of key technologies for European vertical-landing launch vehicles. The consortium will spend three years examining the aerodynamics, aerothermodynamics – that is, in-flight surface temperatures – flight dynamics during both the outward and return flight phases, and navigation and control, as well as structural components, materials and mechanisms.
“Reusable space transport systems equipped with retropropulsion are already being used in the United States. The images and videos from SpaceX were a global sensation. It might therefore be surprising to learn that the physical phenomena underlying the technologies are not yet fully understood, but it is true. As things stand, we are lacking high-quality, experimental data from wind tunnel tests and ground-based demonstrations,” says Ali Gülhan, RETALT Project Coordinator and Head of the Supersonic and Hypersonic Technology Department at the DLR Institute of Aerodynamics and Flow Technology in Cologne.
“By combining these data with numerical simulations, we will acquire a better understanding of the physics and take a leap towards reusable rockets in Europe. Only close and intense cooperation between the research community and the industrial sector can yield the expertise required for the fastest possible implementation of the necessary technologies,” adds Gülhan.
Two concepts for vertical take-off and landing launch vehicles will be examined during the project. The RETALT1 configuration has two stages – similar to the conventional Falcon 9 or Ariane 5 launchers. The first stage of this launch vehicle is equipped with a landing capability. The second launcher (RETALT2 concept) has just one stage. It is designed for smaller payloads and will also use retropropulsion as well as a large aerodynamic surface on its underside to decelerate during its return flight.
Conceptual sketch of RETALT2 (Credit: DLR)
The RETALT team is using reference configurations and smaller-scale models to analyse all aspects. Models at scales of between 1:30 and 1:100 are used for the aerodynamic tests in the DLR wind tunnels. Configurations to analyse structural components like the landing legs are produced in scales of up to 1:3. The technologies will be tested in representative environments during the project. Prototypes can then be built on this basis to run tests in space.
About the Project
RETALT is a European project that was awarded three million euro in funding by the European Commission within the framework of the EU funding programme Horizon 2020. The partner organisations are DLR, CFS Engineering (Switzerland), Elecnor Deimos (Spain), MT Aerospace (Germany), Almatech (Switzerland) and Amorim Cork Composites (Portugal).
The DLR Institute of Aerodynamics and Flow Technology is responsible for coordinating the project, the design of the reference configurations and assessment of the aerodynamics and aerothermodynamic behaviour by means of wind tunnel testing and computational fluid dynamics (CFD) simulations. The Supersonic and Hypersonic Technology Department at the DLR site in Cologne and the Spacecraft Department team at the site in Göttingen are participating in the project.
CFS Engineering is also conducting CFD simulations and is additionally responsible for the dissemination and exploitation of the project results. Elecnor Deimos is examining the flight dynamics and developing the guidance, navigation and control concept for the reference configurations. MT Aerospace is developing structural components such as the landing legs, as well as aerodynamic control surfaces. They will also produce scaled demonstrators for the structures. Almatech is developing mechanisms for the structural components and is responsible for designing a thrust vector control (TVC) system. Amorim Cork Composites is creating the thermal protection system (TPS) for critical components, especially the base area of the launch vehicles, which will be tested in the wind tunnel using a hot exhaust plume.
14 responses to “DLR Teams with 5 European Companies to Develop Reusable Launch Vehicles”
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The reusability opportunity came knocking at the Europeans’ door many years ago but they chose not to answer.
it will be curious where this goes
Intereresting how they are all copying the VTVL design of SpaceX. I wonder how many boosters and hoppers they are willing to lose before they get it right, like SpaceX did.
Almost seems like they are concerned that SpaceX reuse is cost effective…
At least RETALT2 looks like Gary Hudson’s clipper.
Considering that a Vulcain-2 engine costs 10 million Euros, and DLR is proposing putting 7 of those Vulcain-2’s in a single RETALT-1 rocket booster, I’d say they can’t afford to lose even a single hopper or boosters. 😛
Otherwise that’s 70 million Euros down the drain each hopper or booster they lose.
Frankly this study won’t generate any new insights worth the paper they are printed on.
Interesting to see the old McDonnell Douglass DC-X entry get considered. I think the ‘death swoop’ would be taken much more seriously this time around. Good luck guys. Just don’t spend so much time and money you never make your money back or you waste time on analysis when you cold fly for real …. Or maybe I want you to do just that … Yeah, I do….. Do that guys, take your time, don’t do any risky flying.
3 years of theoretical studies and some small scale wind tunnel models…
by the time they get the “surprising” result that reusability is indeed viable, Starship and new Glenn will be already flying… *sigh*
They might not eclipse Elon Musk and his SpaceX gadgets but they might at least score better than NASA does with the SLS calamity.
What are they doing with that interstage?
I’m about 50 pages into Zubrin’s “A Case for Space” and I just read the section where he explains why SSTO is a non-starter. Not a revelation. Not that I expect many revelations. I feel like a choir member looking over the latest hymnal. But with regard to SSTO, why do Europeans not believe in the rocket equation? Is it the Star Wars movies?
My bet is any SST designer readily admits to themselves that they’ll be employing drop tanks or upper stages in the system.
I suppose there’s a modest argument to be made that drop tanks don’t fatally compromise a vehicle’s SSTO-ness. Though, if one is going to drop stuff, why not just do a TSTO in the first place? At least if one puts engines on what’s dropped, it can potentially be recovered. But adding an upper stage to an “SSTO” pretty much makes it a TSTO even if the first stage also makes it to at least LEO. And there would seem very little point in doing that. I’m afraid fundamental chemistry added to the Earth’s gravity well make even notional SSTO’s with a dry mass fraction of zero uneconomical given the growing maturity of first-stage recoverability technology.
Oh don’t get me wrong, I’m a TSTO guy. Three stages to orbit. 🙂 However policy overrides engineering in developed countries so people working the problem might have to make some creative calls. If I were backed into that corner, I’d consider those things.
I like the Delta Clipper concept….