Aiaa 98-2850 Mars Ascent Vehicle Flight Analysis Mars Ascent Vehicle Flight Analysis

The scientific objective of the Mars Surveyor Program 2005 mission is to return Mars rock, soil, and atmospheric samples to Earth for detailed analysis. The present investigation focuses on design of Mars Ascent Vehicle for this mission. Aerodynamic, aerothermodynamic, and trajectory design considerations are addressed to assess the ascent configuration, determine aerodynamic stability, characterize thermal protection system requirements, and ascertain the required system mass. Aerodynamic analysis reveals a subsonic static instability with the baseline configuration; however, stability augmentation options are proposed to mitigate this problem. The ascent aerothermodynamic environment is shown to be benign (on the order of the sea-level boiling point of water on Earth). As a result of these low thermal and pressure loads, a lightweight, low rigidity material can be employed as the aftbody aerodynamic shroud. The required nominal MAV lift-off mass is 426 kg for a December 2006 equatorial launch into a 300-km circular orbit with 30-degree inclination. Off-nominal aerodynamic and atmospheric conditions are shown to increase this liftoff mass by approximately 10%. Through performance of these analyses, the Mars Ascent Vehicle is deemed feasible with respect to the current mission mass and size constraints. NOMENCLATURE α Angle of attack APAS Aerodynamic Preliminary Analysis System CD drag coefficient CFD computational fluid dynamics c.g. center-of-gravity Cmα static pitch stability coefficient GRAM Global Reference Atmospheric Model HABP Hypersonic Arbitrary Body Program Isp specific impulse LAURA Langley Aerothermodynamic Upwind Relaxation Algorithm M Mach number MAV Mars Ascent Vehicle MMH Monomethyl Hydrazine MON-25 mixture of Nitrogen Textroxide and Nitrogen Monoxide MSP Mars Surveyor Program N North OTIS Optimal Trajectories by Implicit Simulation p surface pressure p∞ free-stream pressure POST Program to Optimize Simulated Trajectories q heat rate Q-Alpha product of dynamic pressure and angle of attack RCS reaction control system S South 3-D three-dimensional Tw equilibrium wall temperature x radial location along vehicle z axial location along vehicle