1. Parachutes Changed Supersonic portion of descent
0.9 < M < 3
Changed Cd of Hemisflo Ribbon Chutes
Curve fit so Cd is a function of M
More accurate for computerized analysis

2. Parachutes Continued Subsonic Parachute change
Ringslot instead of Ringsail
Ringslots are applicable for velocities in the range of 0.1 < M < 0.9
According to Knacke Cd = 0.60 has been measured for ringslots in the wake of a large aircraft

3. Parachutes Continued Parasail Deployment Parasail instead of Volplane
Knacke has Cd and Cl values
Need to code

4. Parachute Sample Case Without parasail part of descent
Initial Conditions
Altitude at Mach 3 = 17.5 km
Flight Path Angle = 45 deg
Mass = kg

5. Parachute Sample Case Con’t
Supersonic Stage
7 hemisflo ribbon parachutes
D = 25 m
Total Mass = 278 kg
Deployment time = 50 s

6. Parachute Sample Case Con’t
Subsonic Reefed Stage
6 reefed ringslot 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
6 ringslot parachutes let open to full inflation by cutting the reefing line
Total mass = 668 kg
D = 50 m
Deployment time = 71 s
Landing Speed = 25 m/s

8. Altitude History

9. Velocity History

10. Acceleration History (G-load)

11. Tank Sizing
Instead of trying to calculate the delta V’s needed to do spin up we are going to use the delta V’s listed in Table of the Spring’s Final Report

12. Tank Sizing Example Case
Mars Orbit DV:
Entry Angle Change DV:
Spin-up DV:
Enroute RCS/Maneuvering DV:
Total DV:

13. Tank Sizing Example Case
Landing Mass of kg
Total Propulsion mass = kg
Combines all inert masses with propellant and pressurant masses