Exomars mission 2016: A preliminary post-flight analysis of the heat shield during entry on Mars atmosphere

摘要

The EXOMARS 2016 mission was the first (of two) join European-Russian mission aiming at searching the evidence of past extra-terrestrial life on Mars. After a successful launch of the Russian Proton rocket on the 14th of March, 2016, from Baikonour, and several liberation maneuvers while orbiting the Earth, the Breeze M upper stage carrying the Trace Gas Orbiter (TGO) and the Schiapparelli Entry Descent and Landing module started a long journey to Mars. Seven months later, on the 16th of October 2016, the space probe was released on a direct entry path to the red Planet. After a nominal entry and an expected aerodynamic breaking, saturation of the GNC algorithm during the highly dynamic deployment phase of the parachute, leaded to a final free fall of the module and a destructive impact on ground. However, telemetry of the entry phase was recorded and enabled a post-flight analysis of the heat shield behavior. This paper provides an initial assessment of the thermal instrumentation data that is comprised of in-depth temperatures in the TPS made of Norcoat® Liege (a phenolic-impregnated cork based ablator [3]). In addition to an ablation scheme sensitivity analysis and material thermal diffusivity correction, a preliminary inverse analysis is performed where the time-dependent surface heating is estimated from flight-measured subsurface temperature data.