AAE450 Senior Spacecraft Design Goppert, 1 James Goppert Week 6: February 22 th, 2007 Aerodynamics: Reentry Optimization Dynamics and Control: Communication Satellite Orbits Taxi Capsule Vehicle Reentry

AAE450 Senior Spacecraft Design Goppert, 2 Taxi Capsule Vehicle Reentry Assumptions –Delta V from HMO: 500 [m/s] –TCV Total Mass: 30 [mt] (after Delta V burn from HMO) –Landing close to equator Landing Speed –Actual: 4.78 [m/s] –Maximum : 6.7 [m/s] (15 mph) Propellant –2.85 [mt] –Rocket Equation Prediction: [mt] (Jamison)

AAE450 Senior Spacecraft Design Goppert, 3 Taxi Capsule Vehicle Reentry Constraints –Max g load: 12g’s Hover –Altitude: 300 [m] –Time: 60 [s] Parachutes –1 High Mach Drogue –2 Low Mach Drogue –3 Main Chutes Drogue 1 Max g Load Drogue 2 Main Thrust Ignition

AAE450 Senior Spacecraft Design Goppert, 4 Backup Slides James Goppert Week 4: February 22 th, 2007

AAE450 Senior Spacecraft Design Goppert, 5 Landing Phase

AAE450 Senior Spacecraft Design Goppert, 6 Trajectory

AAE450 Senior Spacecraft Design Goppert, 7 Flight Parameters

AAE450 Senior Spacecraft Design Goppert, 8 Position

AAE450 Senior Spacecraft Design Goppert, 9 Parachute Parameters First Drogue –Deployment Mach: 30 –Diameter: 1 [m] –Number: 1 Second Drogue –Deployment Mach: 10 –Diameter: 8 [m] –Number: 2 Main –Deployment Mach: 3 –Diameter: 22 [m] –Number: 3

AAE450 Senior Spacecraft Design Goppert, 10 EOM’s inertial position derivative –i_P_cmo_i = C_ib*V_cme_b + OM_ei_i*P_cmo_i body velocity derivative –b_Vcme_b = (1/m)*F_at_b - (OM_bi_b + OM_ei_b)*V_cme_b + C_bi*g_i body angular velocity derivative – b_O_bi_b = J_b_inverse*(M_at_b - OM_bi_b*J_b*O_bi_b)

AAE450 Senior Spacecraft Design Goppert, 11 Landing Conditional State Controller Gains –hover p controller gain: k_th = 8e2; –landing gain k_ln = 1; –velocity p controller gain k_tv = 2.1e4; if t_hover==0 F_t_b = [0;0;0] elseif (t-t_hover)<t_hover_req F_t_b = k_th*[h_hover-h;0;0]-... k_tv*V_cme_b else F_t_b = k_ln*[0-h;0;0]-... k_tv*V_cme_b end