Conference Paper

Numerical Computation of ExoMars Schiaparelli Communications Blackout Compared with Flight

Authors:
  • UK Space Agency
  • Fluid Gravity Engineering Ltd
  • ESA, European Space Agency
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Abstract and Figures

The European Space Agency flew an entry, descent and landing demonstrator module called Schiaparelli, that entered the atmosphere of Mars on the 19th October 2016. The UHF or-biter relay links with Schiaparelli suffered a period of ∼57.2-seconds of degradation. An end-to-end aerothermodynamic and electromagnetic analysis has been performed using FGE's in-house simulation tools. Multiple points are considered along a best-estimate trajectory reconstructed from available flight telemetry [1]. For the aerothermodynamics, the chemical composition of the shock layer has been modelled using the Park '94 reaction dataset [2]. The combined computation of the electron density in the hypersonic flow and the propagation characteristics determined by the electromagnetic simulations, has enabled an assessment of the blackout period. Due to the inherent assumptions in modelling the dissociated, hypersonic CO 2 environment , the comparison between the numerical simulations and flight data provides a unique validation of the numerical capability to model blackout. This is a valuable secondary validation of trajectory reconstruction exercises. Compared to flight data, the results align well with the onset of blackout but predict a premature exit by approximately 10 to 15-seconds. These discrepancies could be attributed to complications caused by a combination of factors, including high Doppler dynamics and any attenuation, reflection, or spectral broadening effects from the remaining charged particles. The analysis presented has established the validity of the end-to-end approach, but its accuracy depends strongly on the modelling used for the calculations.
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