Mars Exploration Rover Six-Degree-of-Freedom Entry Trajectory Analysis

The Mars Exploration Rover mission delivered the rovers Spirit and Opportunity to the surface of Mars using the same entry, descent, and landing scenario that was developed and successfully implemented by Mars Pathfinder. This investigation describes the premission trajectory analysis that was performed for the hypersonic portion of the Mars Exploration Rover entry up to parachute deployment. In this analysis, a six-degree-of-freedom trajectory simulation of the entry is performed to determine the entry characteristics of the capsules. In addition, a Monte Carlo dispersion analysis is also performed to statistically assess the robustness of the entry design to off-nominal conditions to ensure that all entry requirements are satisfied. The premission results show that the attitude at peak heating and parachute deployment are well within entry limits. In addition, the parachute deployment dynamic pressure and Mach number are also well within the design requirements.