EXOMARS Descent Module EDL Scenario and Spacecraft Architecture
- Paper number
IAC-07-A3.3.03
- Author
Mr. Maurizio Capuano, Alcatel Alenia Space Italia, Italy
- Coauthor
Mr. Vincenzo Giorgio, Thales Alenia Space, Italy
- Coauthor
Mr. Stefano Portigliotti, Alenia Spazio, Italy
- Coauthor
Mr. Carlo Cassi, Alcatel Alenia Space Italia, Italy
- Year
2007
- Abstract
The Exomars mission is the first ESA led robotic mission of the Aurora Programme and combines technology development with investigations of major scientific interest. Italy is by far the major contributor to the mission through the strong support of the Italian Space Agency ASI. ExoMars will search for traces of past and present life, characterize the Mars geochemistry and water distribution, improve the knowledge of the Mars environment and geophysics, and identify possible surface hazards to future human exploration missions. ExoMars will also validate the technology for safe Entry, Descent and Landing (EDL) of a large size Descent Module (DM) carrying a Rover with medium range surface mobility and the access to subsurface. The Exomars project is presently undergoing its Phase B1 with Alcatel Alenia Space-Italy as Industrial Prime Contractor. Spacecraft Architecture The Descent Module is a blunt-shape probe separated from either a Carrier Module (CM) or an Orbiter Module (OM) according to the launcher that would be finally selected for launch the Exomars Spacecraft Composite. So far launches with Soyuz 2b and Ariane 5 from Kuorou have been deeply investigated, however due to the recent information regarding their reduced mass performances for Exomars launches in 2013 (baseline) and 2015 (back-up) alternative launchers are under investigation (e.g. Proton). The DM is currently designed to land on Mars with two alternative airbags technologies: - bouncing and rolling airbags (MER like) - dead bed airbags (vented at touchdown to avoid overturning of the lander) The DM architecture is designed to offer highest flexibility to cope with different mission scenarios imposing constraints on its mass and aerodynamic shape such that the probe ballistic coefficient and the aerothermodynamics parameters can slightly change in order to avoid a huge redesign to comply. Expecting a final decision on the mission scenario and landing approach by mid 2007, a huge redesign is not affordable in view of a 2013 launch and hence a proper compromise has been found in the DM configuration such that with minor changes a safe Entry Descent and Landing can be achieved at no detrimental of the scientific return of the mission. Entry Descent and Landing Performances The definition of EDL trajectory and the achievable landing accuracy is still open due to the fact that mission scenario is not yet consolidated and several various mission options are under investigation. In particular the possible release from hyperbolic approach (in case of DM launched with CM) or from a Mars elliptic orbit (in case of DM launched with OM) play a main role in sizing the EDL System (heat shield, parachute, retrorockets, airbags) and in the landing accuracy for a ballistic-type entry. Moreover, a design suitable for a generic landing site in the required latitude band currently prevents from tuning the design to specific entry conditions. Worst case reference EDL scenarios have been studied such that a reference trajectory valid for a high number of landing sites can be established and used for the consolidation of the DM design irrespective of the final mission option.
- Abstract document