Motor Selection Downsized motor from J1999 to J1299 – Roughly 2:3 scale size and thrust Aerotech J1299 – 850.16 Ns total impulse – 0.68 s burn time – 1253.93 N average thrust
Motor Justification Flight simulations with J1999 overshot 1 mile Less thrust with J1299 decreased altitude J1299 still has short burn time – Limits affect on scientific payload – Fast acceleration to maximize compressive forces
Vehicle Design Changes Length decreased by 0.5 inches Fin size increased – Increases drag force to assist altitude reduction – Root chord length moved from 10 to 12 inches Extra space in lower body section – Smaller motor has shorter casing – More room for ejection charge – Potential space for excess electronics
Max Altitude: 5302 feet Max Velocity: 903 ft/sec Velocity at Rail : 110 ft/sec
Max drag force: 119 Newtons Average Motor Thrust: 1300 Newtons
Recovery System Design Rocket is made of 3 concentric tubes: 1)Nose 2)Payload 3)Booster
System Deployment Two charges are located in each red square In the booster activate at apogee Charges in the nose activate once rocket has descended to 700 ft.
Materials Used 20 ft of elastic shock chord (10 in both sections) One 36in X-form Parachute Green Fiber blow-in natural fiber insulation (dog barf) Dry cleaner hangers Pyrodex powder Estes and Copperhead igniters Paper tower Tape Hot glue
Ejection tests Test NumberSpecsResultsComments 11.5 inch length hanger tube, Copper head igniter Successful: exploded from both ends Initial test to check if ejection charge design was viable 21.5 inch split-end tube, 1.1 gram pyrodex charge, Estes igniter Successful: top of test section blown, weight launched into the air First test using test chamber 31.5 inch hanger tube, 1.2 gram pyrodex charge, copper head igniter Successful: top of test section blown, weight launched into the air Conducted in test chamber, more energetic than test 2 42 inch hanger tube, 1.7 gram pyrodex, copper head igniter, Kevlar run through test chamber Successful: top of test section blown, weight launched into the air, Kevlar chord intact Conducted in test chamber, Kevlar is viable for use as parachute chord 51.5 inch hanger tube, 1.4 gram pyrodex charge, Estes igniter, conducted in booster tube of scale rocket, dog barf insulation Charge was far too powerful for the tube, kicked out the top of the motor, insulation confirmed to work Amount of powder used was based on tests for the full scale rocket: scale rocket diameter of 38mm, full scale diameter is 54mm
3:4 scale of competition rocket. Used F-50 Aerotech motor. Carried Raven Altimeter connected to two ejection charges. Carried additional back up ejection charge connected to motor. Successful test, both charges were deployed.
Strain gage testing- test the strain gages and data loggers with simulated loads. Payload integration testing: