Plasma testing of heat shield concepts for high speed Earth re-entry

Such a vehicle will be subjected to a harsh environment. Appropriate materials, most probably ablative, have to be selected and subjected to delta qualification. The delta qualification of such a high-speed vehicle Thermal Protection System (TPS) concepts will require a combination of analysis and ground testing. European facilities have already been assessed and used for orbital entries in the frame of various programmes (Hermes, Atmospheric Re-entry Demonstrator, X-38, Inflatable Re-entry Technology). SCIROCCO is one of them.

Much higher flow energies are encountered for high-speed Earth entries than for orbital ones. As a result, the materials used for the heat shield are specific, and the physical processes encountered and instruments needed are quite different. The production of such high energy flows or the performance of measurements may even be beyond the reach of the present test facilities, and may require either additional developments or the definition and validation of a specific methodology.

The objective of the present work is to assess the capability and readiness of the CIRA facilities to support the EVD programme that was initially a part of the Aurora programme, for the validation of the thermal protection system. Such a task shall also involve tests at a demonstration level. EVD is however no longer in the Aurora Exploration Programme planning, but it is greatly representative of the conditions that MSR Return Vehicle will encounter on its way back to Earth.

The objective of this activity is to assess the readiness of the CIRA ground test facilities for the design and verification of the thermal protection system of the EVD. First, specifications for aerothermal tests, in terms of trajectories, flight regimes, instrumentation, etc. shall be studied for high-speed Earth entries corresponding to EVD mission. The main problems to be assessed (e.g. ablation mass loss, plasma radiation, catalytic efficiency, etc.) shall be reviewed, accounting for the material and concept of the TPS.

The performance maps of SCIROCCO and their potential evolution shall be compared to the requirements for the EVD. The facility calibration, operational status, instrumentation shall also be given. The results of the work shall be collected in an electronic database. The adequacy of the facility for the specific aspects of high speed Earth entry shall be highlighted. Its readiness shall be evaluated. Their main characteristics and limitations shall also be reported. The model(s) requirements (shape, size, and materials), the facility configuration, the test set-up, instrumentation and conditions shall be selected. Models shall be manufactured and tested in the selected facility (or facilities) and for the selected set-up and conditions representative of EVD re-entry peak heating conditions. The test results shall be analysed and interpreted. Recommendations for future development of instrumentations and/or facilities shall be given. The resulting aerothermal databases shall be made available to the EVD/MSR project.