In this thesis a methodology is developed to reconstruct flight dynamics and atmospheric conditions along the entry trajectory of Mars Entry, Descent & Landing (EDL) vehicles. Flight simulation, synthetic data generation, and reconstruction methods are developed and validated using flight data from 2008 Phoenix and 2012 Mars Science Laboratory (MSL) entry vehicles. Conventional methods and equations, used in for example accelerometer data processing and flight dynamics, are described in detail to make the work understandable and reproducible. A 1-D flow model is implemented to retrieve scientifically useful atmospheric profiles from a single pressure port on the MSL. The model is approximate but generally applicable to Mars EDL vehicles and trajectories. Using CFD and wind tunnel experiments a forebody pressure model is developed, allowing reconstruction of the wind-relative attitude and atmospheric density. The model is applied to wind tunnel measurements, as well as to simulated and actual data from multiple pressure ports, referred to as a FADS (Flush Air Data System). A theoretical FADS uncertainty analysis is performed and the first to be applied to the 2016 ExoMars Schiaparelli mission. The FADS was useful in the post-flight EDL analysis of Schiaparelli, conducted here and the first to include pressure data. In addition, a novel and efficient optimization method is proposed for the FADS port locations. It is validated by exhaustive brute force searching, and applied to simulated ballistic entry. Finally, the requirements for wind estimation for this type of mission are discussed.
|Qualification||Doctor of Engineering Sciences|
|Award date||7 Sep 2021|
|Place of Publication||Brussels|
|Publication status||Unpublished - 2021|