ESA GNC Conference Papers Repository
GNC Design and Performance of the Exomars EDL Demonstrator
The ExoMars Entry Descent Landing Demonstrator Module (EDM), is part of the ExoMars 2016 mission. ThalesAlenia Space is responsible for the Guidance Navigation & Control (GNC) system and the EDL End-to- End (E2E) Simulator developed for the verification of the EDL design, including GNC tasks and performances. The main objectives of EDL Demonstrator are: 1) to demonstrate the European capability of landing on Mars and 2) to embark and validate EDL system technologies suitable for delivering science surface payloads. The EDM Surface Platform (ESP) is the sub-module that safely lands on Mars surface; it includes the propulsion and the system service equipments to perform the EDL and is accommodated inside the EDM with suitable thermal protections. The selected EDL design is similar to the ones of the previous NASA/JPL landing missions on Mars; however there are specific challenges, like the handling of three days of coast (between the separation from Orbiter and the entry in the Mars atmosphere) with the EDM in hibernation, the implementation of a backshell/parachute avoidance maneuver during the Landing phase to prevent the re-contact in flight of the ESP with the EDM separated items, the usage of PWM thrusters (CHT-400) with a fundamental OFF-ON-OFF cycle duration twice the control cycle one, the precise control of the ESP until about 2 meters above ground for subsequent free-fall touchdown with crushable panels. This paper describes the architecture of the EDM GNC limiting the discussion to the propelled phase. For this phase, the design and verification methodologies will be explained and some relevant results achieved from the Exomars functional End-To-End simulator running Monte-Carlo simulations in realistic mission scenario and from an dedicated analytic assessment methodology will be presented and compared.