Reliable space transportation systems can only be economically efficiently developed through the use of verified design tools and technologies. In particular, it is important to use powerful design tools to find a suitable balance between simulation through numerics and trial and error through testing. In this context, real flight data on structural response to harsh aerothermal loads are very rare. Due to the fact that individual, selective flight experiments cannot answer all open questions, the development of a flight programme with consecutive, scientifically and technically evolutionary and thus economically justifiable flight experiments is central.
In this framework, through the ATEHEAt project, DLR will thus enable research into a number of technology gaps for reusable space transport systems and establish itself as an indispensable partner for European space transport development. For this purpose, the main core of the research activities will be following on the development of two flight experiments: a flight experiment in hypersonic regime, with maximum Mach number above 8 for a relatively long time (longer than 120 s), and a flight experiment with a one-stage innovative hybrid rocket.
As part of the ATHEAt project, our Institute with the departments Space System Integration and Ceramic Composites and Structures, is responsible for the design and manufacture of the thermal protection system of the rocket's forebody, which is exposed to severe aerothermal conditions during flight. In particular, with respect to the previous flight of the STORT sounding rocket, the nominal flight trajectory for ATHEAt is even more challenging, foreseeing hypersonic conditions with Mach number between 9 and 10 for almost 3 minutes.
On the basis of the significant experience gained during the previous STORT project, the forebody TPS will consist of a thermally stable C/C-SiC segmented external structure, specifically designed and setup for the new flight conditions and the considered challenges.
Integrated to the TPS structure, two experiment, developed in collaboration with the “Supersonic and Hypersonic Technologies” department of the DLR Institute of Aerodynamics and Flow Technology, are present to test two different active cooling approach during the flight.
Furthermore, at the end of the forebody a module with four flaps connected to a central actuator is present in order to collect precious data on the real behavior of control surfaces in hypersonic regime.
Finally, for the one-stage hybrid rocket flight experiment our “Ceramic composite structures” department is responsible for the design and manufacturing of high-temperature structures for the motor components subjected to the highest thermal loads, such as the engine nozzle.
