CRITICAL DESIGN REVIEW Plantation High School Team Optics
LAUNCH VEHICLE DIMENSIONS Total Length: 105 Diameter: 4 Upper Airframe: 40 Lower Airframe: 46 Coupler: 12 Coupler Band: 1.5 Composed of G12 Fiberglass Nose Cone Length: 16.5 4 shoulder length
PAYLOAD DIMENSIONS External photometer clips have a length of 2 and width of ¼. Internal payload sled has a height of 6 and diameter of 4.
KEY DESIGN FEATURE: FINS Set of 3 fins Material: 3/32 G10 Fiberglass Root Cord: 1.5 Stability: 3.11 calibers
KEY DESIGN FEATURE: NOSE CONE Fiberglass 4:1 Ogive (Madcow Rocketry) G12 Fiberglass Easy to finish High compressive strength Composite tipped
KEY DESIGN FEATURE: AIRFRAME G12 Fiberglass (Madcow Rocketry) Easy to finish 4 diameter Heat resistant Lower Airframe: 46 Upper Airframe: 40
KEY DESIGN FEATURES: BULKHEADS, THRUST PLATE, AND CENTERING RINGS Material: G10 Fiberglass Heat resistant Can withstand the force of ejection Thickness of centering rings: 1/8 The centering that connects the drogue to the recovery harness has an eyebolt Thickness of bulkhead: 1/8 Thickness of thrust plate: 1/4 The thrust plate will be milled in the classroom using the DaVinci CNC
KEY DESIGN FEATURE: COUPLER BAY Diameter: 3.9 Length: 12 G12 fiberglass for coupler and coupler band 1.5 coupler band length 2 bulkhead endcaps Each endcap bulkhead (G10 Fiberglass) is 0.25 thick. There is a lip for the inner diameter of the coupler.
KEY DESIGN FEATURES: DUAL DEPLOYMENT (DROGUE) Precision LP 18 Parachute Terminal Velocity: 101 ft/s Deployed at apogee with a black powder charge. The ignitor is long enough to reach behind the parachute, so the Drogue is pushed out of the lower body tube. Tethered with a D-link to an eyebolt on the centering ring and the coupler. 40 ft of ½ Tubular Kevlar recovery harness
KEY DESIGN FEATURES: DUAL DEPLOYMENT (MAIN) TAC-84 Ripstop Nylon Hemispherical with 6 shroud lines Deployed at 450 ft AGL with a black powder charge. The ignitor is long enough to reach behind the parachute, so the Main is pushed out of the upper body tube. Tethered with a D-link to an eyebolt on the Upper bulkhead and the coupler. 40 ft of ½ Tubular Kevlar recovery harness Terminal Velocity: 16.36 ft/s
KEY FEATURES: DUAL DEPLOYMENT (ELECTRONICS) Two PerfectFlite StratoLogger SL100 altimeters Two 9v batteries The altimeters and batteries are secured onto an alt-bay and to the coupler bay using threaded rods.
FINAL MOTOR CHOICE K635-RL Ceseroni No built-in eyebolt Specifications Total impulse: 1994.4 N Average Thrust: 637.3 N Burn time: 3.1 s Diameter: 54 mm Length: 19.2 Total Mass: 1768 g Propellant Mass: 1115 g
THRUST-TO-WEIGHT RATIO AND RAIL EXIT VELOCITY RAIL EXIT VELOCITY Rail Exit Velocity: 63.2 ft/s Distance to Stable Velocity: 4 ft THRUST-TO-WEIGHT RATIO Thrust-to-Weight Ratio: 7.58
FLIGHT STABILITY AND STATIC STABILITY MARGIN STATIC STABILITY MARGIN Static stability Margin: 3.20 calibers Stability Margin (Rail Exit): 3.51 Calibers Center of Gravity/Pressure Markings Center of Gravity (From Nosecone): 68.14 Center of Pressure (From Nosecone): 81.03
MASS STATEMENT AND MASS MARGIN Gross Liftoff Weight: 18.9 lbs Weight After Motor Burn: 16.5 lbs Mass Margin: 1000 g Component Upper Airframe Coupler Bay Lower Airframe TOTAL Mass 3019 g 1158 g 3991 g 8572 g
RECOVERY HARNESS Both the main and drogue parachutes use 40 of ½ Tubular Kevlar A picture showing an SLI team from last year using ½ tubular Kevlar during the full-scale test launch
RECOVERY: DESCENT RATES Main Parachute: 16.36 ft/s Drogue Parachute: 101 ft/s
RECOVERY: KINETIC ENERGY KINETIC ENERGY AT LANDING Section Kinetic Energy (ft-lbf) Upper 27.83 Coupler 10.68 Lower 26.52 Total 65.03
DRIFT CALCULATIONS Wind Speed (mph) Max Drift (feet) 0 0 5 563.88 10 1127.76 15 1691.63 20 2255.51
TEST PLANS AND PROCEDURES Test Objective Success Criteria Methodology Rocksim Flight Simulations Achieve a stable simulated flight, apogee of approx. 5280 ft, drift within 2500 feet, and landing velocity within KE requirements. Stable ascent, apogee within 15% of 5280 feet, drift distance under 2500 feet, landing velocity under 20 ft/s. Set launch conditions to those in Huntsville. Poor simulated apogee may be solved with a motor change. Poor stability is resolved with fin redesign or ballast. Drift distance or descent velocity resolved with parachute changes.
TEST PLANS AND PROCEDURES Test Objective Success Criteria Methodology Fin Flutter Speed Calculation Test the rigidity of the fin geometry against the forces of flight. A flutter velocity that is greater than the maximum velocity reached by the launch vehicle. Velocity is calculated using the equation in the Apogee Rockets newsletter Issue 29. If a flutter velocity is reached that is less than the maximum velocity during flight, fin geometry will be changed.
TEST PLANS AND PROCEDURES Test Objective Success Criteria Methodology Ejection Ground Test Determine the black powder charge amount required to separate the upper and lower body tubes. Breaking of shear pins and complete separation of both tubes. An online calculator is used to find a preliminary ejection charge amount. The vehicle is packed ready for flight with ejection charges located behind the parachutes to push them out; charges are activated with launch stand from safe distance. If complete separation is not achieved, the test is repeated with a larger charge.
TEST PLANS AND PROCEDURES Test Objective Success Criteria Methodology Subscale Test Launch Validate the launch vehicle design features. Stable flight, apogee within 250% margin of simulations, and successful dual deployment recovery system functionality. The subscale uses the dual-deployment recovery system, altimeter arming system, and construction methods of the full-scale. An unstable flight will result in fin redesign or use of ballast to alter stability margin. Failure of any subsystem will result in a re-flight after resolving the issue.
TEST PLANS AND PROCEDURES Test Objective Success Criteria Methodology Fin and Bulkhead Stress Tests Validate construction integrity. Fins and bulkheads resist applied stresses. Apply stress to each fin and tug on the recovery harness at each point of attachment. If fins or bulkhead attachment points give in to stress, they will be removed and reattached.
TEST PLANS AND PROCEDURES Test Objective Success Criteria Methodology Payload Bench Test Confirm payload functionality. The payload gathers and logs atmospheric data from the photometer. The LED photometer will be assembled with an Arduino, accelerometer, and SD logger and tested outside with the correct program to deduce atmospheric data. If the bench test is unsuccessful the payload design will be redesigned and reimplemented.
SUBSCALE FLIGHT RESULTS Launched on January 5th The predicted apogee was 984 feet, while the actual flight reached 960 feet. Estimated that the coefficient of drag is around 0.75 Wind speeds of 15-17 mph above 300 ft 55 F 41% humidity
RECOVERY TESTS Dual deployment was successfully achieved during the subscale launch. The drogue parachute ejected at apogee. The main parachute ejected at 300 feet. Ejection tests will be carried out for the full-scale launch vehicle.
PAYLOAD DESIGN REVIEW LEDs Vary from green to IR for various atmospheric calculations. Arduino Mega Processes data from accelerometer and LEDs, logging to SD shield. Triple-axis Accelerometer (LIS3DH) Measure vehicle acceleration in the x, y, and z planes to find vehicle attitude. SD Logger (MicroSD card breakout board+) Writes the accelerometer and photometer readings to MicroSD Card
PAYLOAD BACKGROUND Diodes exhibit the photoelectric effect in which they generate current when they absorb light within their emission band. Current produced is proportional to the amount of electromagnetic radiation in the atmosphere of the frequency of the diode. Diodes can be used to measure atmospheric optical thickness, photosynthetically active radiation, and water vapor levels.
PAYLOAD INTEGRATION Three LED photometers are secured around the airframe with a screw above and below a 3D printed clip. The battery, Arduino, and accelerometer are located on a sled that slides into the payload bay. The sled is composed of two 3D printed plates and a top handle screwed into aluminum U-rails.
INTERNAL INTERFACES The drogue recovery harness is fastened with D-links to eyebolts on the centering ring and the coupler. A barrel swivel connects the drogue parachute to the recovery harness. The main recovery harness is fastened with D-links to eyebolts on the upper bulkhead and the coupler. A barrel swivel connects the main parachute to the recovery harness.
EXTERNAL INTERFACES The launch vehicle utilizes a motor with an electrical motor ignitor connected with alligator clips to a 12 volt DC launch system that returns to off when the input is released. (check wording) No other external circuitry is utilized. Mr. Vallone attaching the alligator clips to the motor ignitor
FIN FLUTTER The maximum vehicle velocity before a fin experiences flutter is calculated using the following equation (found in the Apogee Rockets newsletter Issue 291) Vf = a G 1.337AR 3 P(λ + 1) 2(AR + 2)( t c )3 However, the fin dimensions must be simplified as the calculation only works for trapezoidal type fins
FIN FLUTTER CALCULATION Root Chord (c r ) = 8.375 in Tip Chord (c t ) = 3.433 in Area (S) = 1 2 8. 375 + 3. 433 4. 776 = 28.198 in2 Aspect Ratio (AR) = 4.7762 28.198 =.809 Taper Ratio (λ) = 3.433 8.375 =.410 Pressure (P) = 2116 ( 40.203+459.7 ) 5.2526 = 1744.832 lbs/ft 2 = 12.117 lbs/in 2 518.6 Thickness (t) = 0.09375 in Speed of sound (a) = 1. 4 1716. 59 (40. 203 + 460) = 1096.4036 ft/s G (Young's modulus) = 16.5 GPa = 2320603.804 psi Vf = 1096. 4 2320603. 804 1. 337 0. 798 3 12. 117 (0. 402 + 1) = 1339 ft/s 0. 09375 2(0. 798 + 2) ( 8. 53 )3 Simulated maximum vehicle velocity = 657 ft/s
REQUIREMENTS VERIFICATION The team will meet all of the requirements in the Statement of Work (SOW) by following the plans outlined in the CDR report. A GANTT Chart is followed to ensure appropriate completion of requirements.
OUTREACH Starting January 17 th, the Plantation High School Aerospace program will host Open Lab Nights with local middle and elementary school students. The students will design and build their own rockets under the supervision of the Aerospace program students. After construction is complete, the students will launch their rockets at a local field.