Mid-Lift-to-Drag Ratio Rigid Vehicle Control System Design and Simulation for Human Mars Entry

Abstract

The Mid-Lift-to-Drag Ratio Rigid Vehicle (MRV) is a proposed candidate in the NASA Evolvable Mars Campaign's (EMC) Pathfinder Entry, Descent, and Landing (EDL) architecture study. The purpose of the study is to design a mission and vehicle capable of transporting a 20mt payload to the surface of Mars. The MRV is unique in its rigid, asymmetrical lifting-body shape which enables a higher lift-to-drag ratio (L/D) than the typical robotic Mars entry capsule vehicles that carry much less mass. This paper presents the formulation and six-degree-of-freedom (6DOF) performance of the MRV's control system, which uses both aerosurfaces and a propulsive reaction control system (RCS) to affect longitudinal and lateral directional behavior. NomenclatureCA , CY , CN = aerodynamic axial, side, and normal force coefficients Cl , Cm , Cn = aerodynamic rolling, pitching, and yawing moment coefficients g = acceleration due to gravity I = moment of inertia L = aerodynamic reference length M = Mach p , q , r = inertial roll, pitch, and yaw rates t = time ̅ = dynamic pressure S = aerodynamic surface area = angle of attack = sideslip angle = bank angle = control system gain = aileron deflection = elevon deflection , = frequency and damping coefficient = torque 1 Aerospace Engineer, Flight Mechanics and Trajectory Design Branch NASA JSC/EG5.

Human Mars Entry, Descent, and Landing Architecture Study: Rigid Decelerators

“…While this targeting analysis was performed using 3DOF simulations, much work has been done throughout the study to refine the 6DOF entry controller. That work is summarized in Ref [12,13].…”