Preliminary Design Review California State University, Long Beach USLI November 13th, 2017
System Overview
Launch Vehicle Dimensions Total Length 108in Airframe OD 6.17in. ID 6.00in. Couplers OD 5.998in. ID 5.775in. Motor Mount 75mm Centering Ring Thickness 0.2 in
Material Selection - Airframe, Nose Cone & Couplers Fiberglass Significantly stronger than blue tube Much cheaper than carbon fiber More environmentally resistant than blue tube Low thermal and electrical conductivity
Material Selection - Fins Carbon Fiber Highest yield strength Highest strength to weight Great environmental resistance Affordable for fins
Material Selection - Bulkheads & Centering Rings Aluminum Stronger than wood Inexpensive Easily manufactured Adds stability to coupler sections
Material Selection - Miscellaneous Avionics tray will be 3D printed using ABS material Epoxy for fin and centering ring attachment is Aeropoxy Light epoxy
Motor Selection 75mm Cesaroni 4263-L1350-CS Provides sufficient thrust to reach an apogee well over a mile
Stability From the tip of the nose cone Center of Gravity (CG)=68.73in Center of Pressure (CP)=85.05in Stability Margin=(85.05-68.73)/6.17in=2.64 cal
Flight Simulations Total Mass-42.0lbs Velocity off rod -66.9ft/s Projected Apogee- 5467 ft Thrust-to-weight ratio-7.21
Recovery System Altimeter Vendor Model Cost (1-5) Weight (1-5) Features (1-5) Integration (1-5) Total Eggtimer Eggtimer Quark 5 5 1 2 13 PerfectFlite Stratologger CF 4 4 3 4 15 MissileWor ks RCC2+ 4 4 3 3 14 MissileWor ks RCC3 Sport 3 2 4 4 13 Adept AltS2-50k 2 2 2 3 9 Altus Metrum Easy Mega 1 3 5 4 13
Recovery System (cont.) GPS Unit Comparison Vendor Model Cost (1-5) Weight (1-5) Dimensions (1-5) Integration (1-5) Total Transolve BeepX 5 2 1 2 10 Eggtimer Eggfinder 4 4 1 2 11 BigRedBe e BRB900 TX/RX 3 4 3 4 14 Altus Metrum TeleMetrum 3 4 3 3 13 Altus Metrum TeleMega 2 4 1 4 11
Recovery System (cont.) 13 Coupler Piece Primary and Backup Altimeters BRB900 GPS Tracker U-Bolt - 1,075 lb Maximum Capacity (Nylon Harness) Rotary Switch
Recovery System (cont.) Type of Parachute Parachute Size and Model Location Relative Descent Velocity (fps) Drogue Parachute 20" FC TARC Low and Mid Power Parachute Nose Cone + Payload Bay Aft End 92.99 Main Parachute 84" FC Iris Ultra Standard Parachute Propulsion Bay Forward End 17.80
Recovery System (cont.) Wind Speed (mph) Wind Speed (fps) Drogue Drift (ft) Main Drift (ft) Total Drift (ft) 0 0 0 0 0 5 7.33335 376.958952 6 205.9929775 582.9519301 10 14.6667 753.917905 2 411.985955 1165.90386 15 22.00005 1130.87685 8 617.9789326 1748.85579 20 29.3334 1507.83581 823.9719101 2331.80772
Recovery System (cont.) Kinetic Energy for Each Independent Section Upon Landing Section Weight (lb) Mass (slugs) Descent Velocity (ft/s) Kinetic Energy (lb-ft) Payload Bay 13.879 0.431373199 17.80 68.3381421 9 Avionics Bay (After Event 2) 4.769 0.148225289 17.80 23.4818502 8 Propulsion Bay 12.983 0.403524623 17.80 63.9263707 8
Recovery System (cont.)
Rover
Rover Overview Ground clearance Payload Space Distance Solar panel
Rover: Design Considerations Cylindrical Rover Stability, complexity, volume efficiency Triangular Able to deploy in multiple orientations. More possibilities of failure. Rectangular Wheg wheels Simple design
Rover: Design Choice Triangular Able to deploy from any orientation. Bogie system Gearbox
Rover: Design Choice Triangular Maximizes available space in rocket. Houses all electronics inside the body.
Rover Controls and Electronics Controller Arduino Nano Motorshield Sensors Inertial Measurement Unit (IMU) Rangefinder Control Yaw Suppression Obstacle Avoidance
Rover Deployment Mechanism (RDM)
RDM Summary Purpose: Remotely deploy the rover from the internal structure of the launch vehicle. Design Choice: Single motor One threaded rod and two non-threaded rods Load is driven along threaded rod through a matching threaded nut
Mechanical/Hardware Rotary to linear system for load translation Motor attached to threaded rod Threaded nuts attached to the rover Bulkhead with threaded nut
Electronics/ Control Remotely activate the system 2.4GHz Digital Transmitter/Receiver Motor control Arduino Nano Microcontroller L298N H-Bridge 11.1 V LiPo Battery Provide motor feedback rotary encoder
RDM Schematics Rocket lands Remote rover deployment switch initiated The rover continues to translate, and pushes the nose cone away from the airframe. The rover falls off the rod and initializes the system. Electric motor spins the threaded rod in the loosening direction The nose cone translates along the rod and detaches.
Airbrake Summary Main Goal: Ensure that the rocket achieves target apogee by correcting upward drift velocity after engine cutout. Mechanics: airbrake flaps are deployed by use of a linear actuator. Control: triggering the actuation of the flaps to maintain target velocity.
Airbrake mechanics A linear actuator with a 2 stroke will be used to deploy the flaps from the rocket. The actuator will pull up causing the linkage arms to straighten, deploying the flaps. 4 flaps are used to maximize drag without compromising the structural integrity of the rocket.
Air Brake Control Electronics 2 Stroke electric linear actuator Arduino Nano microcontroller Sensors Pitot Tube Airspeed Sensor BMP280 Barometer 6 DOF IMU Control Correct for error in velocity Modeling of system to determine timing, duration, and deflection of flaps Closed versus open-loop system
Significant Failure Mode - Launch Vehicle Tail Fins shear off during flight Fins are not properly secured to airframe Rocket takes unpredictable flight path Ensure adhesive used is strong enough to handle force of flight. Check adhesive for cracks before launch. Fins not properly aligned Fins not assembled correctly Rocket spins uncontrollably Follow proper procedure when assembling fins Motor centering ring fails Adhesive not properly applied to centring ring Motor launch through the rocket Construction procedures are followed for applying adhesive
Significant Failure Mode - Recovery Parachute does not deploy Parachute gets tangled around rocket Rocket will fall to ground at high velocity Parachute will be integrated in a was to reduce risk of getting tangled Parachute has rip Parachute gets ripped while deploying Rocket descend to quick and get damaged upon impact Team members will be careful during packaging of parachute Altimeter failure Faultily altimeter Parachute will not deploy Use two altimeter for redundancy
Significant Failure Mode - Airbrakes Structural damage to airbrake system during launch Material of airbrake not strong enough Airbrakes will not deploy or become damaged Verify through testing that airbrake can handle force of flight Airbrakes do not deploy at desired altitude Programming failure Rocket will not make desired altitude Test airbrakes programming during subscale launch Airbrake flaps fly off during flight Flaps made not to handle force of launch Rocket become unstable Verify through testing flaps can handle force of flight
Significant Failure Mode - Rover Rover damaged during landing Impact of landing more than expected Rover becomes inoperable Make sure rover is secure in place before launch and test to ensure it can handle force of landing Rover damaged during flight Rover not secure in place Rover becomes damaged and inoperable Ensure rover is secure put in the rocket Rover gets stuck on rock Rover not capable of handling terrain Rover gets stuck and unable to make distance requirement Design rover to handle all terrains and verify that through testing
Significant Failure Mode - RDM RDM does not deploy when activated Programing failure Rover will not deploy Verify that programing will act as desired through testing RDM deploys during flight Electronic failure Nose cone opens up during flight Ensure electronics work properly through testing RDM becomes damaged during flight RDM materials cannot handle force of launch RDM damaged and rover will not deploy Choose strong material that can handle the force of flight
Testing Wind tunnel Test drag force and drag coefficient of airbrake flaps Drop testing Test strength of components to ensure they can handle forces of flight and landing Programing and Electronic testing Test all programs and electronics to ensure that they act in the way that they are supposed to Shock and Impact testing Test all components of launch vehicle to ensure that they can handle the shock of the flight and the impact of landing
Project Plan
Timeline Subscale Launch in November, Full scale built by February, Full scale launch in March
Airbrake Timeline
Educational Engagement Event Date Estimated Attendees Girls Day at the Beach (1) 3/2017 100 Aerospace Rocket Symposium 9/7/2017 200 Girls Day at the Beach (2) 9/2017 200 Introduction to Engineering Presentations 11/2017 100 MAES Latinos in Engineering Bottle Rocketry 4/2018 60 High School Engineering Presentation 12/2018 500 TOTAL 1160
Budget-Expenses Subteam Projected Expenses RDM $178.84 Rover $553.58 Avionics $538.63 Recovery $517.10 Launch Vehicle $2,295 Airbrake $137.83 Business $8,670 Total $13,870.91
Budget-Income Source Income College of Engineering $4,200 AIAA - CSULB $1,500 Fundraisers $1,500 ASI Travel Grant $7,000 Sponserships Total $600 $14,800