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The Hermes II drogue system is designed for deployment at apogee +/- 10 seconds. It is designed to operate at a temperature of 300 F because it could contact the side of the motor case. The current design temperature is arbitrary; it will be updated after a static fire. The deployment conditions are given by sims. Two edge cases were considered (A) a light, powerful rocket launched pointing straight up and (B) a heavy, weak rocket launched at an angle of 10 degrees. Case A gives the maximum mach number at deployment, which is .8. We begin to worry about trans and supersonic effects at or below this number. Case B give the maximum dynamic pressure at deployment. The Hermes II drogue deployment force is lower than the Hermes I deployment force because the rocket is going higher. At higher altitudes the air is thinner, so at the same speed the dynamic pressure is lower.
- Make inventory tags.
- Measure existing drogue lines. Put length in inventory and in parameters. Put other details here. Put a diagram of the markings on the line here.
- Cut one 500 lb line. Have everyone practice tying double figure 8. Attach line to drogue.
- Create a deprecated Hermes soft goods box. Put the old line in the box.
- Sign off on the drogue lines on the parameters sheet.
- Measure existing drogue riser. Put length in parameters. Put other details here. Put a diagram of the markings on the line here.
- Cut one 2500 lb line. Demonstrate finger trapping and sewing. Write procedure.
- Determine the material required for the TD loops. Write procedure.
- Have everyone manufacture 2 TD loops. Store in the orange box.
DESIGN TODO
Main
The Hermes II main system is designed for deployment at 2000 ft above the launch site under a range of reasonable masses. It is designed to operate at a temperature of 150 F because it the inside of the rocket could reach that sitting on the pad.
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