Preliminary Assessment of MSL EDL Sensitivity to Martian Environments

The Mars Science Laboratory Mission (MSL) will be launched during fall 2009 and will reach Mars at its northern summer season. The MSL entry, descent, and landing system is designed to land the heaviest rover, with the best landing precision, and highest elevation capability to date on Mars. The challenging ellipse size and high elevation sites are achieved by use of a guided lifting entry vehicle. The final landing site will be selected one year before launch and therefore the system's performance is to be evaluated for all possible environments in all possible landing sites. This paper discusses EDL sensitivities to support landing site safety preliminary assessment; it illustrates the sensitivities to Martian features identified as relevant to the EDL design. The Martian environmental parameters to which the EDL system is evaluating its sensitivities are atmospheric density and pressure, wind characteristics, speed of sound and terrain characteristics of slope distribution, rock abundance, and radio frequency backscatter. This paper briefly describes the EDL timeline and illustrates the EDL system features critical to understanding EDL performance in the Martian Environment. A preliminary assessment of EDL performance used to support characterization of landing site safety guidelines is presented. Critical sensitivities to atmospheric density, wind speed, local speed of sound and terrain slopes uncertainties have been preliminarily identified and discussed within.