The ongoing research work at the Institute of Space Propulsion focuses on fundamental research into the combustion processes in rocket engines and high-speed air-breathing ramjet/scramjet engines for future space transport systems. Cryogenic liquid rocket engines, gel rocket engines, hybrid rocket engines, rocket engines with advanced green propellants (for e.g. hydrazine replacement) are main working areas. The research and technology development activities cover all relevant aspects of rocket engines with flowable propellants, i.e. feeding system, rheology and flow processes, injector processes and atomization, mixing, combustor and thrust chamber processes, heat transfer and cooling, nozzle flows, system analysis, etc. The Institute is also concerned with the development and application of advanced intrusive and non-intrusive measurement techniques for high-temperature gas and multiphase flows. The Institute is also working on the use of ceramic fiber materials in rocket combustion chambers.

^{The DLR Site of Lampoldshausen (© DLR)}

High-performance test facility technology
The unique test facilities are the basis for developing engine technologies to operational maturity and ensuring their quality. With the P4 altitude simulation test bench, DLR is indispensable for the development of the Vinci upper stage engine, which will be the most powerful engine in Europe in the future. With the help of these tests, DLR scientists gain insights into the engine behavior, which will be used by the manufacturer ArianeGroup for final optimizations. The Vinci engine, which is powered by a high-energy combination of liquid hydrogen and liquid oxygen, will power the upper stage of the new European Ariane 6 launcher. ArianeGroup is the industrial prime contractor for the future Ariane 6 launch vehicle. 

^{Test run of the Ariane 6 upper stage engine Vinci at the test facility P4.1 (© DLR)}

Scientific expertise and unique test facilities to develop the Ariane 6
DLR Lampoldshausen has built the P5.2 test facility on behalf of ESA for testing the future upper stage of the new Ariane 6 launch vehicle. These include tests on refuelling and defuelling as well as hot run tests of the stage with the Vinci engine. It will help DLR in Lampoldshausen to qualify not only engines and individual components, but also complete cryogenic upper stages. This new upper stage test facility ideally complements DLR's test and inspection facilities.

^{Implementation of the new upper stage for the Ariane 6 into the test facility P5.2 (© DLR)}

Technologies for the next generation of engines
In addition to the development and operation of test facilities, DLR scientists are researching advanced technologies for future space engines on the P8 technology test facility. The research focuses on the investigation of the injection of fuel components, their mixing and combustion, the expansion of hot gases in the nozzle and the thermal loading of the combustion chamber structures. The experimental investigations of these individual processes are carried out by the scientists with the aid of model combustion chambers in which realistic conditions prevail for rocket engines. An in-depth understanding of these processes is the basic pre-requisite for an optimal design of future engines.

Research for a greener space propulsion future
The development of future propulsion systems is affected by different and partly contradictory demands like more complex mission requirements, higher reliability, environmental and safety aspects, and of course also cost reduction. Thus, intensive research and technology development activities are necessary to develop and test advanced and greener propellants and propulsion systems. Scientists and engineers are working in laboratories and the M11 test complex with several very promising candidates, which have the potential to replace actually used propellants which are difficult to handle like hydrazines. 

 
^{Preparation of a test run in the vacuum test chamber at M11 (© DLR)}

For further information about the DLR Institute of Space propulsion please visit our webpage: 
http://www.dlr.de/ra/en