University

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University Student Launch Initiative

MILE HIGH
YELLOW JACKETS
Competition Rocket
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• Due to not receiving funding that was promised, a
  4 diameter fiberglass rocket has been chosen.
• The rocket built as the payload test rocket will
  be modified and become the competition rocket.
• It is a Performance Rocket Mad Dog Dual Deploy
  kit that will be modified with the anti-zipper
  design by modifying the booster section and
  adding a coupler.
• Below is a Rocksim drawing of the rocket. It is
  shown loaded with an Aerotech K1275 motor. The
  margin of stability is 2.83.

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• Diameter 4
• Fins 3
• Total Length 92
• Nosecone 20
• Forward Airframe (Main Section) 24
• Middle Airframe (Drogue Section) 18
• Aft Airframe (Booster Section) 30
• Dry Weight (no motor) 230 oz. 14.4 lbs
• Ready-to-fly Weight 302.6 oz. 18.9 lbs
• Top Flight Recovery Parachute 70
• Top Flight Recovery Drogue 18

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• According to Rocksim simulations, the Aerotech
  K1275 takes the rocket closest to 5280 with a
  drag coefficient of 0.72.
• ThrustCurve.org shows this motor taking the
  rocket to 5537 altitude although their
  simulations tend to be slightly high.

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• Average Thrust 1275 N 286.6 lbf
• Average Thrust/Weight Ratio 15.2
• Rail Exit Velocity
• Launch guide length 96
• Rail Exit Velocity 94.1252 ft/s
• Minimum velocity for stable flight 44 ft/s
• Minimum velocity for stable flight reached at
  23.6023 In.

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Trajectory Analysis Rocksim Flight Profile

• Main Parachute Decent Rate 25 fps
• Drogue Decent Rate 100 fps

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• Main
• Pressure Desired 15 psi
• Diameter 4
• Compartment Length 24 8 16
• Grams of Black Powder 15/2500 16 16 1.536
  grams
• Drogue
• Pressure Desired 15 psi
• Diameter 4
• Compartment Length 18 8 10
• Grams of Black Powder 15/2500 16 10 0.96
  grams
• Based on these calculations, 1.5 grams will be
  used for the main and 1 gram will be used for the
  drogue. The rocket will be ground tested with
  these amounts before its first flight to ensure
  that the proper amounts were chosen.

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Motor Tube
Location of Drogue Chute
Payload Section
Location of Main Chute
Pressure Taps