This picture was taken in Onera's R5Ch blow down windtunnel at Meudon. The hypersonic flow, coming from the left side, is Mach 10 (~1.5 km/s).
copyright © ONERA 1996-2005 - All rights reserved
Visualization of the shock wave in front of the capsule model
is made possible by electron beam fluorescence (1)
(Thierry Pot - DAFE)
The model within this hypersonic flow is the Mars Sample Return Orbiter (MSRO). For this study, Onera was under contract to Cnes, in the framework of a Nasa/Cnes cooperation to collect Mars soil samples.
MSRO was to get into Mars' orbit using aerobraking, i.e. achieving deceleration by intense atmospheric friction. The objective of Onera's study was to make sure that the heat shield would withstand such friction. In this experiment, the thermal fluxes at Mach 10 were measured in the windtunnel with an infrared camera.
- Electron Beam Fluorescence (EBF)
Technology using an electron gun to produce a intense beam along which nitrogen molecules from the air are ionized and emit electromagnetic photons. These photons produce the natural colors on the picture above. Laser beam fluorescence suits to the low densities involved in hypersonic flow.