Transcript Payload
Launch Vehicle Propulsion Payload Recovery Vehicle Dimensions • • • • Total length of 116.5 inches 4.0” Airframe (3.9” Inside diameter) Fin span of 3.91” Separates into three sections Top Nosecone Payload Vertical Wind Turbine Middle Drogue Parachute Piston Altimeters Bottom Main Parachute Motor (Plugged) Fins Materials- Airframe • Entirely BlueTube 2.0 • Heat and Humidity Resistant • Lightweight compared to alternatives Product Sample Length Weight Weight per inch Blue Tube 3" x 48" x .062 wall 577.9 grams 12.04 grams per inch Plain phenolic 3" x 48" x .062 wall 423.9 grams 8.83 grams per inch Glassed phenolic 3" x 48" x .062 wall 868.8 grams 18.1 grams per inch Filament wound 3" x 48" x .062 wall fg 907.2 grams 18.9 grams per inch Source: Alwaysreadyrocketry.com Materials- Airframe • Exceptionally strong material • Vulcanized paper fiber with water resistant resin • Tubing was “a component inside a warhead of the 155mm Howitzer, and 105mm Abrams Tank ordinance” –Always Ready Rocketry • Is expected to withstand forces of launch Materials- Airframe • Maximum load of 3079 lbf (3 inch tube) • Peak Stress of 5076 psi (3 inch tube) • Impact resistant Source: Apogeerockets.com Source: Alwaysreadyrocketry.com Materials- Fins • Fins – Composite board with hardwood edging – Fiberglass outer layer – Honeycomb Nomex composite inside – Must have edging to airfoil Photos from GiantLeapRocketry.com Materials- Fins • • • • One-Third the weight of G10 Fiberglass Retains rigidity Airfoil edging will be of birch plywood Surface will be scored with hobby knife and drilled into to increase surface area • Through-the-Wall assembly to the motor mounting Materials- Fins Materials- Epoxy • Loctite 30 minute Epoxy – All motor mounting and internal parts – Allows for absorption time – Less brittle, stronger bond • Loctite 5 minute Epoxy – Fin Fillets Bulkheads & Centering Rings • 4-ply birch plates • Each 3/16” thick • All rings and bulkheads will be double thick • Overall stronger plate • More surface area to glue to Materials- Other • Vertical mounting boards – 1/4” to 3/8”plywood – Used in payload and electronics bay • Nose cone – Impact resistant plastic • Tail cone – Urethane tail cone from Public Missiles to reduce drag Stability Margin • Stability margin of 2.01 calipers before launch • Fins will be constructed last • Fin size will be adjusted to keep this value Stability Analysis • 2.01 stability margin will allow for error • Small drag forces from: – Nosecone screws – Solar panel’s edge – Pressure bleed off holes – Miscellaneous • Margin will rise to 3.35 calipers after burnout Vehicle Safety Verification • Sub-scale launch Dec. 11th (backup Dec. 18th) – Verifies stability and altimeter setup • Strength tests on fins and bulkheads • Heat, humidity, and warp testing – Oven, freezer – Soak in water • First full scale launch in early February with dummy payload Construction Safety • All personnel trained to use power tools • Two people working on a part minimum • Gloves, aprons, and goggles during construction • Masks when products with fumes are used – Epoxy – Paint Launch Vehicle Propulsion Payload Recovery Motor Selection • Aerotech K700W • Plugged forward closure Motor K1050 K660 K750 K700 K828 K570 K635 Manufacturer AeroTech Cesaroni Cesaroni AeroTech AeroTech Cesaroni Cesaroni Total Max Average Impulse (NThrust Burn Thrust sec) (lbs) Time (s) (lbs) 2522.038 488.29 2.46 230.48 2437.380 242.55 3.69 148.49 2361.966 212.74 3.14 169.16 2283.680 363.52 3.59 142.89 2157.195 293.11 2.50 193.98 2070.258 200.69 1.70 119.34 1973.146 175.06 3.13 141.76 * For rocket to reach 5,000 feet AGL Max Rocket Dry Weight* (lbs) 21 20 19 18 16 15.5 14 • Current projected dry mass = 15.4 lbs •Will have room for error Motor Selection • Propellant from Giant Leap Rocketry • Hardware from Apogee Rockets – AeroTech RMS-54/2560 casing – Plugged forward closure – Eyebolt threads for solid parachute mounting point Source: Apogeerockets.com Thrust to Weight Ratio • Thrust to weight = 6.81 to 1 with current plan • Acceleration of 364 ft/s2 on Launch – 11.3 G’s • Rail Exit Velocity = 81.0228 ft/s Thrust Curve Source: ThrustCurve.com Plan for Motor Safety Verification • Inspect for any cracks or dents on casing • Certified personnel assemble motor – George or Jack Sprague (Mentors) • Inspect assembly • Aerotech K700 motor is not a prototype and has been launched before Launch Vehicle Propulsion Payload Recovery Baseline Payload Design • Measures voltage and current output of a flexible solar panel • Observe changes in the strength of the Earth’s Magnetic Field • LabPro Data logger records from all sensors simultaneously • Accelerometer triggers data recording • Data stored inside rocket, until retrieval Payload Design- Structure • Housed in the Modular Payload System (MPS) • Three compartments • Sensors secured with metal strapping • All plywood • Stainless steel support rods Data Logging System • LabPro Data Logger from Vernier • Programmed to start taking data when accelerometer reads 7 G’s of acceleration • Longer pad stay time, can take many readings from just ascent and descent • Supplies power to all sensors • Lithium AA batteries for reliable power source Solar Panel System • Solar Panel, current probe, voltage probe, resistors, and data logger • Voltage probe in parallel around a 10 ohm resistor • 30 ohm resistor in series to burn off voltage for sensors • Current probe in series • Solar panel leads go through airframe to sensors Solar Panel Flexible Solar Panel • Two donated by FlexSolarCells.com for experiment Magnetic Field System • Vernier magnetic field sensor • Isolated from all other electronics to reduce risk of interference • Will measure a peak voltage when sensor points to magnetic South • Rocket must spin so that we know it points South at some time Magnetic Field Probe •Field strength across the globe varies from 3.1 x 10-5 to 5.4 x 10-5 Teslas •Typical variance in 25 nano Teslas on a given day in one location Vertical Wind Turbine • Magnetic Field sensor reads peak when pointed at magnetic south • Catches horizontal wind and causes the rocket to spin Significance • Solar power is becoming cheaper and easier to integrate • Viability of flexible solar on objects where direct sunlight is not always possible • Magnetic field experiment could be used in the future for detailed data on the changes in the Earth’s magnetic field Plan for Payload Verification • System ground testing – Set up all sensors and record sample data – Will onboard electronics interfere with magnetic field sensor? • Strength test components of MPS for the amount of G-forces it will go through • Double check that systems working before launch • Use new batteries before every launch Launch Vehicle Propulsion Payload Recovery Baseline Recovery System Design • 24” TAC-1 Drogue Parachute at apogee – Backup ejection 2 seconds after apogee • 84” TAC-1 Main Parachute at 700 feet – Backup ejection at 500 feet • Swivels on each parachute • Perfectflite MiniAlt/WD and HiAlt45K altimeters • Radio transmitter for locating the rocket after landing Recovery System • Shock cord is 9/16” wide nylon strap – 2000# rated – 26’ on drogue 20’ on main • Quick-Links for easier chute packing and repairs (if needed) • U-Bolt parachute mounts • Altimeter ejections have been staggered – Reduce risk of over-pressurizing airframe Backup Main Chute Ejection (500 feet) Primary Main Chute Ejection (700 feet) Primary Drogue Chute Ejection (at apogee) Backup Drogue Chute Ejection (2 sec after apogee) Engine Burnout Flight Events and Ejections Electronics Bay • Each altimeter will have its own 9V battery and arming switch • All connections will be secure so that no circuit breaks occur Plan for Recovery Safety Verification • Ejection charge ground tests in January • Verify descent velocities with Rocksim • Verify vertical wind turbine does not tangle cords • 2000 lbs rated heavy-duty 9/16” nylon shock cord • Altimeter testing in a vacuum chamber • Verify function of radio transmitter in a ground test • Use ohm meter to check ejection canisters before installing into rocket Questions?