EADS Space Transportation Research Articles

Entry system development for Mars Netlander mission

For a long time, EADS SPACE Transportation has been developing specific technologies and engineering capabilities in the field of re-entry. The first achievements were dedicated to ballistic missiles, but since recent years, these skills have found direct application into planetary exploration. Among these missions, EADS SPACE Transportation was involved in: • Huygens program, in charge of the system activities and of the Thermal Protection System. • Beagle 2, launched in June 2003 with ESA Mars Express orbiter, in charge of the Thermal Protection System. More recently, EADS SPACE Transportation was given the responsibility for the development of entry Thermal Protection System for the four NetLander probes, in the frame of the CNES Mars Premier program for which EADS SPACE Transportation has been selected by Alcatel Space for the development of the TPS. EADS SPACE Transportation has based its technical choices, on the Beagle 2 technologies well adapted to this application: • the Norcoat Liège, a lightweight ablative material, for the external thermal protection of both the Back Cover and the Front Shield. • A Nida/carbon layers sandwich for the Front Shield structure. For Programmatic point of view, the main objectives of this approach is to reduce the development risks and to increase the mission robustness in capitalizing on Beagle 2 experience and on a sound industrial basis, and to control the cost. For technical point of view, the major challenges of the Mars Netlander mission defined by the Prime is the mass saving and the design flexibility. Therefore, the materials have been optimised in line with these challenges: • At the beginning of the phase B, a refined mechanical concurrent engineering has been performed for the Front Shield structure to optimize every part which are governed both by global requirements (volume allocation, overall stiffness and deformations) and by local ones (reinforcement zones under the sufM brackets, I/F with the Back Cover). • Heat flux tests have been performed in the mission extreme conditions combining heat loads and aerodynamic shear stress to increase the material behaviour knowledge (ablation profiles, temperature prediction/results correlation) and at the end to reduce the sizing margins.

Launcher Attitude Control: Some Answers to the Robustness Issue

This paper presents the main results obtained in the frame of PIROLA, a 3 years research working group on robust control of launchers, under financial support of CNES induding ONERA, EADS Space Transportation, the control departments of Supelcc and SUPAERO, and CNRS/LAAS.The first part of the paper addresses the general problem of the attitude control of launchers specially the robustness concern.In the second part the different synthesis methods which have been proposed and tested during the project are described. Some of them address the stationary control problem and have therefore to be associated to an interpolation algorithm to be implemented. Two other methods aim at designing nonstationary controllers. The advantages and limits of each method for this particular problem are emphasized.