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Parachutes

Parachutes. Supersonic portion – Hemisflo Ribbon Most practical for velocities up to Mach 3 Subsonic portion – Ringsail Parachutes Historically proven success rate Reefed for a short time to decrease max g-load during deployment and increase parachute stability. Parachutes Continued.

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Parachutes

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  1. Parachutes • Supersonic portion – Hemisflo Ribbon • Most practical for velocities up to Mach 3 • Subsonic portion – Ringsail Parachutes • Historically proven success rate • Reefed for a short time to decrease max g-load during deployment and increase parachute stability

  2. Parachutes Continued • Landing parachute – Volplane • Developed for the Pioneer spacecraft, tested with the Gemini capsule • (L/D)max = 3.0 • Provide softer landing and maneuverability

  3. Parachute Code • Written by Jeremy Davis for Spring 2001, modified by Jon Edwards • Consists of 6 Matlab files • subreefeom.m / supereom.m • subreefdiam.m / superdiam.m • supersubhm.m • acceldiff.m

  4. Parachute Sample Case • Initial Conditions • Altitude at Mach 3 = 17.5 km • Flight Path Angle = 45 deg • Mass = 57520 kg

  5. Parachute Sample Case Con’t • Supersonic Stage • 7 hemisflo ribbon parachutes • D = 25 m • Total Mass = 278 kg • Deployment time = 42 s

  6. Parachute Sample Case Con’t • Subsonic Reefed Stage • 3 reefed ringsail parachutes • Reefing factor = 0.3 • Inflated area = 0.3 * max inflation area • Reefing time = 10 s

  7. Parachute Sample Case Con’t • Subsonic Un-reefed Stage • 3 ringsail parachutes let open to full inflation by cutting the reefing line • Total mass = 222 kg • D = 38.5 m • Deployment time = 39 s • Landing Speed = 55.7 m/s

  8. Altitude History

  9. Velocity History

  10. Acceleration History (G-load)

  11. Propulsion Systems • Shuttle OMS Engine - Retro/Boost • F = 6000 lbf • Isp = 313 s • NTO and MMH propellants (non-cryo) • Mass = 134.7 kg

  12. Propulsion Systems Cont’d • Marquardt R-40A – RCS System • F = 500 lbf • Isp = 306 s • NTO and MMH propellants (non-cryo) • Mass = 10 kg • 24 R-40A’s – 8 in each plane • Also used on Shuttle Orbiter

  13. Engine Tank Sizing Code • tanksize.m • Written by Casey Kirchner for Spring 2001, modified by Jon Edwards • Changes • No descent or hovering delta v’s • No heat shield • OMS Isp, expansion ratio and RCS Isp • Landing mass • Vehicle Dimensions

  14. Tank Sizing Sample Case • Initial Conditions • Mass = 57520 kg • Periapsis lowering/raising delta v = 20 m/s • Hab length = 16.5 m • Hab diameter = 13 m

  15. Tank Sizing Sample Case • Oxidizer tank (cylindrical w/ hemi ends) • Length = 0.90 m • Diameter = 1.00 m • Fuel tank (cylindrical w/ hemi ends) • Length = 0.94 m • Diameter = 1.00 m • Pressurant Tank (spherical) • Diameter = 1.36 m

  16. Tank Sizing Sample Case • Oxidizer • Tank mass = 10.78 kg • Propellant mass = 1725.03 kg • Fuel • Tank mass = 11.00 kg • Propellant mass = 1078.14 kg • Pressurant • Tank mass = 4.70 kg • Pressurant mass = 6.07 kg

  17. Tank Sizing Sample Case • Structural support • According to Humble we add 10% of total inert mass for structural support • Structural support mass = 4.19 kg • Total Mass = 3250.54 kg

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