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Illinois Space Society Tech Team USLI C DR Presentation. Contents. Vehicle Specifications Performance Characteristics Recovery System Flight Testing Payload. Vehicle Design. Vehicle Dimensions. Length: 108 in Diameter: 6 in Component dimensions shown . Final Motor Choice.
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Illinois Space Society Tech Team USLI CDR Presentation
Contents • Vehicle Specifications • Performance Characteristics • Recovery System • Flight Testing • Payload
Vehicle Dimensions Length: 108 in Diameter: 6 in Component dimensions shown
Final Motor Choice • Aerotech L2200 75 mm motor, Aeropack retainer and adapter
Motor Characteristics Max Thrust 3101.8 Ns Average Thrust 2246.6 Ns Total Impulse 5104 Ns Mass pre Burn 10.55 lbs Post Burn 5.55 lbs
Stability Analysis • CG 18.78 inches above CP • Static stability margin of 3.13 • Marginally overstable, but has been flown at similar stability successfully
Takeoff Characteristics Using an 8ft high, 1.5 in standard launch rail, the predicted takeoff characteristics are: Thrust to weight ratio: 13.4:1 Rail exit velocity: 73.8 ft/s These are well within acceptable ranges for normal launch conditions
Vehicle Mass For detailed vehicle mass, view section 3.1 G. All masses in pounds. • Nosecone: 2.725 • Upper Airframe and Coupler: 10.787 • UAV: 3.83 • Booster Airframe with Motor: 27.382 • Parachutes and associated hardware: 6.163 • Total, on the pad: 50.89
Recovery System Characteristics Dual deployment system, with • Two redundant Stratologger altimeters for charge control • Telemetrum for GPS and tracking • Independant switches and batteries for all altimeters • SkyAngle 36 Classic 2 Drogue, ~74 ft/s terminal velocity • Rocketman 16 ft Main, ~ 15 ft/s terminal velocity
Kinetic Energy at Key Phases Kinetic Energy During Descent (ft-lb) Under drogue: Nosecone: 230.6 Upper airframe/ coupler: 912.80 Booster airframe: 1890.2 UAV: 323.9 Under main: Nosecone: 9.02 Upper airframe/ coupler: 35.7 Booster airframe: 74.24
Drift Calculations Until rocket begins to descend, movement will be into the wind due to weathercocking; drift is dependant on motion during ~110 sec. descent. Drift during test flight was 772 ft with 8 mph winds; difference is motion into the wind during ascent.
Subscale Flight Stability Subscale model had static stability margin of 3.5, similar to full scale vehicle. During flight, vehicle experienced little deviation from vertical during ascent before arcing over.
Subscale Flight Test • Wildman Darkstar Mini • Roadrunner Rocketry F45 motor • Modified with small avionics bay in the nosecone for data collection
Predicted Performance OpenRocket predicts apogee at 1079 ft
Subscale Flight Test Results Measured apogee of subscale was 1146 ft, giving a 6% overshoot
Full Scale Flight Test Stability CG: 220 cm CP: 308 cm Stability: 34.5 in
Simulated Full Scale Flight Test The rocket was flown with a four foot upper airframe and the original nosecone, weighing in at 54.5 lbs.
Full Scale Flight Test Results The final apogee is observed as 5007 ft, which a 315 ft (~6%) overshoot. Overshoot correlates to that found from subscale flight test.
Recovery System Testing Charge testing and one full scale flight test have been successfully completed. All charges successfully deployed at proper times during flight, and there was no unexpected separation. Future charge testing will occur after the new design components are completed and the UAV is prepared for charge testing, to ensure continued successful deployment.
Payload Integration UAV will be folded, attached to shock cord, and loaded into booster airframe below drogue parachute. When the drogue deploys at apogee, the UAV will be pulled out of the rocket. The UAV and rocket will undergo testing to ensure proper ejection charge size.
Payload Design Changes since PDR: • No longer using worm gears; torsion springs provide enough force to unfold arms • Base will be made from machined aluminum, not 3D printed. • Controls and other systems are retained
Testing UAV will undergo a battery of tests to ensure flight readiness, including: • Static test article for controls testing • Ground, charge, flight, deployment, and full scale flights testing
Interfaces Physical interface on the vehicle are quicklinks and eyebolts connecting different sections through shock cord. Communication with the ground happens through two channels: • An X-Bee transceiver on the UAV allows communication with the ground station • A Telemetrum Altimeter allows tracking of the vehicle during flight
Tether The Defy Gravity tether will be used to secure the UAV to the launch vehicle, via the recovery harness, until the RSO gives permission to release. The vehicle will be released and will descend under parachute until stable, then unfold and fly autonomously.
Status of Requirements Subscale Test Launch: Dec 16 Charge Tests Jan 10-11 Full Scale Test Launch 1: Jan 12 UAV Static and Control Testing: Feb 4-8 UAV Integration and Charge Testing: Feb 8-11 UAV Drop and Parachute Testing: Feb 11-15 Full Scale Flight Test: Feb 23-24 or Mar 2-3