SALTO – Technologies for Europe's reusable rockets
SALTO: Technologies for Europe's reusable rockets
The SALTO project is focused on the upright landing of a reusable launcher stage. SALTO, short for ‘reuSable strAtegic space Launcher Technologies & Operations’, together with the European Space Agency's (ESA) Themis programme, is laying the technical foundations for the next generation of European space transporters. These new systems will be more cost-effective, more sustainable and more versatile because of their reusability.
The prototype first stage will lift a few metres off the ground during testing and land upright again, with thrust provided by the new generation Prometheus® throttleable engine demonstrator. With the help of SALTO, various technologies are also being developed for a future, larger demonstrator powered by three Prometheus® engines, with greater range and speeds of several times the speed of sound. The German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) is involved in both flight tests and the development of future technologies.
DLR’s role and consortium
The SALTO consortium brings together 25 partners from 12 countries, including five research centres, 14 large companies and seven small and medium-sized enterprises (SME):
- Research centres: DLR, CNES, ONERA, IRT Jules Verne, INCAS
- Large companies: ArianeGroup SAS (Leitung), ArianeGroup GmbH, MT Aerospace AG, Safran Data Systems, Safran Electronics & Defense, Avio S.p.A., Sabca, Thales Alenia Space Belgium S.A., GTD Sistemas de Información S.A., GMV Aerospace and Defence SA, Deimos Engineering and Systems S.L.U, Sener TAFS SAU, Swedish Space Corporation, Amorim Cork Composites SA
- Start-ups and SME: ID-Services, Shark Robotics SARL, G.L.Electronic s.r.o, SIA WIT Berry, Realtime Technologies Ltd, SpaceForest sp. z o.o.
DLR is contributing to SALTO in a variety of ways, with its expertise gained in recent years on projects developing and researching reusable vertical landing rockets, in particular RETALT and CALLISTO.
Three DLR institutes are specifically contributing their expertise. The Institute of Aerodynamics and Flow Technology is responsible for the aerodynamic and aerothermal design of the larger demonstrator with three Prometheus® engines. Extensive fluid dynamics calculations and wind tunnel tests are being carried out for this purpose. The Institute of Space Systems is contributing to the flight vehicle's design by conducting landing dynamics simulations and tests. It is also providing wireless communication technologies for the demonstrator, alongside a hybrid navigation system with integrated health monitoring, which will be onboard during flight tests. Additionally, the Institute of Flight Systems is developing an actuator health monitoring system. The Institute of Aerodynamics and Flow Technology together with Institute of Space Systems are also investigating how the technologies developed in SALTO can be scaled up for flight demonstrators to full-scale carrier systems.
Maximising synergies and reducing complexity
A key ingredient for SALTO’s success is to make the system as simple as possible by reducing the number of components and simplifying their interactions – a lesson learnt from the Space Shuttle era and exemplified by SpaceX’s Falcon 9.
The path to a flight-ready Themis demonstrator is paved with several intermediate steps. The engine (powered by liquid oxygen and methane with 120 tonnes of thrust) will first be ignited on the ground without taking off. This will be followed by a vertical jump test ('hop test'), in which the demonstrator takes off vertically, reaches an altitude between 20 and 100 metres and then returns vertically to Earth. Test campaigns will be carried out at the Esrange Space Center in Kiruna, Sweden.
Funded by the European Union
SALTO has received funding from the European Union's Horizon Europe research and innovation programme under grant agreement No 101082007.
Views and opinions expressed are however those of the author(s) and do not necessarily reflect those of the European Union. Neither the European Union nor the granting authority can be held responsible for them.