National Aeronautics and Administration

Cassini / Huygens Probe Entry, Descent, and Landing (Edl) at Titan Independent Technical Assessment National Aeronautics and Administration

Publisher Marketing: Starting in January 2004, the NESC has received several communications from knowledgeable technical experts at NASA expressing shared concerns (mainly at the Langley Research Center (LaRC) and Ames Research Center (ARC)) about Huygens mission success. It was suggested that NASA become more technically involved directly in the analysis of Huygens' entry, descent and landing (EDL) focusing on the following primary concerns: 1. The parachute deployment trigger performance and the resultant effects on the operation of the parachute system, and 2. The determination of the radiative heating environment at Titan by ESA and the corresponding thermal protection system (TPS) response. A NESC Team was formed and tasked to provide an independent assessment of these concerns. Tasks required for this independent assessment included: 1. Development of an aerodynamics database for the entry configuration. 2. Development of an aerodynamic database for the probe under each of the three parachutes. 3. Development of an opening loads model for each of the three parachutes. 4. Development of detailed aerothermal environments. These environments were comprised of the convective (laminar and turbulent) and radiative heat rates and integrated heat loads. 5. Update of the Titan atmosphere model to include the Cassini observation of Titan on November 15, 2004 (Project has denoted this as the "TA" pass). 6. Development of a Monte Carlo trajectory simulation analysis capability. 7. Determination of entry flight path angle that maximizes the mission success probability. 8. Determination of the TPS evaluation trajectories. 9. Determination of applicability and appropriateness of radiative heating models. 10. TPS performance assessment.