Critical Design Review Carnegie Mellon Rocket Command Jan 16, 2018 - - PowerPoint PPT Presentation

Project SCOTTIE: Critical Design Review

Carnegie Mellon Rocket Command Jan 16, 2018

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Table of Contents

1. Vehicle Overview …………………………………………………………………………………………. 2. Subscale Launch ………………………………………………………………………………………..... 3. Apogee Targeting System …………………………………………………………………………….. 4. Recovery Subsystem ……………………………………………………………………………………. 5. Mission Performance Predictions ……………........................................................... 6. Payload Overview ……………………………………........................................................... 7. Requirements Compliance Plan ………………........................................................... 8. Logistics ……………………………………………………………………………………………………….. TBD TBD TBD TBD TBD TBD TBD TBD

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Table of Contents

1. Vehicle Overview …………………………………………………………………………………………. 2. Subscale Launch ………………………………………………………………………………………..... 3. Apogee Targeting System …………………………………………………………………………….. 4. Recovery Subsystem ……………………………………………………………………………………. 5. Mission Performance Predictions ……………........................................................... 6. Payload Overview ……………………………………........................................................... 7. Requirements Compliance Plan ………………........................................................... 8. Logistics ……………………………………………………………………………………………………….. TBD TBD TBD TBD TBD TBD TBD TBD

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Vehicle Overview

3:1 Ogive Nosecone Ballast Containe r Nosecone Shoulder UAV Bay UAV Electronics Sub- Compartment Recovery Bay GPS ATS Bay 3 Tapered Fins 75 mm Motor Tube Motor Cap, Base, and Plate UAV Nosecone Airframe Upper Airframe Middle Airframe Lower Airframe Main Chute Drogue Chute =Switchbands 4

Summary of Vehicle Specifications

Vehicle Section Dimensions Mass (lb) Ogive Nosecone 18” Length x 6.17” Base Di. X 4” Shoulder 2.44 Nosecone Airframe 8” L x 6.17” OD 0.927 Upper Airframe 28” L x 6.17” OD 3.5 Middle Airframe 20” L x 6.17” OD 2.5 Lower Airframe 24” L x 6.17” OD 3 UAV Bay 15” L x 6” OD 5.41 Recovery Bay 10” L x 6” OD 3.53 ATS Bay 10” L x 6” OD 3.99 Fins [Next Section] 2.75 Motor Retention [Next Section] 3.17 Switchbands (x3) 2” L x 6.17” OD 0.25 Total 6.17” D x 105” L 36.75 (Dry), 46.81 (Wet)

*All airframe components, couplers, and bulkheads are G10 fiberglass.

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Fin Design

• 3 Fins
• Trapezoidal planform
• 7 degree bevel cross

section

• G10 Fiberglass
• 3/16” Thick
• Fin flutter calcs.:
• Flutter

Velocity- 2909 ft/s

• Max rocket

velocity- 650 ft/s

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Motor Retention System

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Table of Contents

1. Vehicle Overview …………………………………………………………………………………………. 2. Subscale Launch ………………………………………………………………………………………..... 3. Apogee Targeting System …………………………………………………………………………….. 4. Recovery Subsystem ……………………………………………………………………………………. 5. Mission Performance Predictions ……………........................................................... 6. Payload Overview ……………………………………........................................................... 7. Requirements Compliance Plan ………………........................................................... 8. Logistics ……………………………………………………………………………………………………….. TBD TBD TBD TBD TBD TBD TBD TBD

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Primary Subscale Model

Parameter Value Length 57.5 in Diameter 3.125 in Dry Mass 93 oz (5.8125 lb) Wet Mass (CTI I212) 110 oz (6.875 lb) Wet Mass (CTI I236) 107 oz (6.6875 lb) Airframe material G12 Fiberglass Airframe thickness 0.0625 in

Schematic As-built

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Ejection Charge Testing

Drogue Charge

• 1.0 g: Unsuccessful
• 1.2 g: Successful

Main Charge

• 1.0 g: Successful

Conclusion

• 1.2 g black powder for drogue charge
• 1.0 g black powder for main charge

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Launch 1 – Dec 9th

• Good liftoff and ascent
• Drogue chute deployed at apogee
• Main ejection charge failed to separate

airframe at 700 ft

• No visible damage on landing
• Sensor data up until apogee still relevant
• Result: Unsuccessful

Main Chute Failure Drogue Chute Success Liftoff Success

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Launch 2 – Dec 9th

• Unstable liftoff – insufficient rail exit velocity
• Resulted in steep liftoff angle
• Drogue ejection charge failed to deploy
• Main chute successfully deployed at 700 ft
• Zippered airframe and damaged fin
• Cause by chute deployment or impact

with tree

• Sensor data not valid for duration of flight
• Result: Unsuccessful

Zippered Airframe Damaged Fin Liftoff Instability

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Secondary Subscale Model

Schematic As-built

Parameter Value Length 30.5 in Diameter 1.63 in Dry Mass 7.56 oz Wet Mass (Estes D12-5) 9.07 oz Airframe material Kraft Paper Airframe thickness 0.079 in 13

Launch 3 – Jan 4

• Good liftoff
• Main parachute successfully deployed 5

seconds after burnout

• Successful recovery
• Sensor data valid throughout flight
• Result: Successful

Liftoff Success Recovery Success

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Sensors

Primary Subscale

• Stratologger CF Altimeter
• Control recovery ejection charges
• Record altitude data for launch

verification

• MPL3115A2 Altimeter
• Record altitude data for ATS

system testing

• BNO055 IMU
• Record IMU data for ATS system

testing Secondary Subscale

• Stratologger CF Altimeter (Recovery)
• Record altitude data for launch

verification

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Post-Launch Analysis

OpenRocket simulations accurately model the in flight altimeter data recorded

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Coefficient of Drag Estimation

• The ATS altimeter altitude data was

differentiated to get velocity and acceleration

• (less noise than Stratologger data)
• Acceleration was converted into drag

force based on mass of the subscale

• Coefficient of drag was calculated based
• n the recorded velocity of the subscale
• Average value of 0.39
• High variability

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Table of Contents

1. Vehicle Overview …………………………………………………………………………………………. 2. Subscale Launch ………………………………………………………………………………………..... 3. Apogee Targeting System …………………………………………………………………………….. 4. Recovery Subsystem ……………………………………………………………………………………. 5. Mission Performance Predictions ……………........................................................... 6. Payload Overview ……………………………………........................................................... 7. Requirements Compliance Plan ………………........................................................... 8. Logistics ……………………………………………………………………………………………………….. TBD TBD TBD TBD TBD TBD TBD TBD

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ATS Overview

• Active prediction and control

system predicts apogee and enacts the appropriate control

• Electronically controlled drag

inducing flaps respond by extending and retracting to control speed

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ATS Timeline

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Flap Deployment System

• Features central hub

controlling flap extension through rotation

• Couples to

electronics bay using threaded rods and servo connection

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Air Brake Flap Design

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Air Brake Flap Performance

• Flap CD evaluated at

key positions to provide prediction model a precise measurement

• f CD at different flap

positions

• Rectangular flap design

produces a predictable, interpolable CD curve

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Electronics Bay

Sensor system

• 4x MPL3115A2

altimeters

• BNO055 IMU

Computational system

• Raspberry Pi 3

Deployment system

• SB2282SG servo

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Flap Deployment System and Electronics Bay Connection

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Prediction and Control Overview

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Apogee Prediction Model Design

Given a state Xt including an altitude ht , vertical velocity st and attitude ht

• 1. While (st > 0)

Set Xt to the prediction of Xt+dt

• 2. Take ht to be the vehicle’s apogee.
• Repeatedly predicting vehicle state one time step into the future using

known launch vehicle physics and flap position based drag model

• Once vertical speed has reached 0, we take the current altitude to be

apogee

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Controller Design

• The controller response Ut corresponds to the distance of extension of the air brakes.
• p and i correspond to the coefficients to the proportional and integral terms of error,

respectively.

• The function e(t) is the current difference between predicted apogee and desired

apogee.

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Prediction and Control Error Analysis

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ATS Testing Procedures

Component Test Success Criteria Software Speed testing to ensure apogee prediction cycle can occur within receipt of new sensor data Prediction of apogee can be made in less than 0.51 seconds Sensor Integration Data transmission testing to ensure that prediction and control system receives timely and accurate information ATS code on Raspberry Pi 3 successfully receives accurate data from each sensor Electrical Speed testing to ensure that flaps can extend and retract within receipt of new sensor data Full extension and Retraction of flaps can

• ccur within 0.51 seconds

Mechanical Stress testing to ensure that flaps can withstand maximum expected load during flight Flaps can extend and retract while under a load of 29 lbs. Total System Full performance test of ATS during test launch of SCOTTIE Apogee Targeting System allows SCOTTIE to reach an altitude of 5100 +- 17 feet

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Table of Contents

1. Vehicle Overview …………………………………………………………………………………………. 2. Subscale Launch ………………………………………………………………………………………..... 3. Apogee Targeting System …………………………………………………………………………….. 4. Recovery Subsystem ……………………………………………………………………………………. 5. Mission Performance Predictions ……………........................................................... 6. Payload Overview ……………………………………........................................................... 7. Requirements Compliance Plan ………………........................................................... 8. Logistics ……………………………………………………………………………………………………….. TBD TBD TBD TBD TBD TBD TBD TBD

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Recovery Subsystem

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Flight Profile

• 1. Launch
• 2. Motor Burnout

& ATS Activation

• 3. Unpowered flight

ATS Active ~12 sec

• 3. Apogee at 5100 ft

& ATS Deactivation

• 4. Drogue Deploy

0-1 sec after apogee

• 5. Main Deploy at

700 ft AGL

• 6. Landing

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Recovery Bay

• Dimensions
• Length: 5”
• Mass: 22 oz
• Key Features
• 2 Stratologger CF altimeters
• 3D printed 9V battery case and cover
• Shurter rotary switch standoffs
• Plywood circular sled for mounting

hardware

• Terminal blocks, black powder canisters,

and E-matches for ejection charges

• Coupler coated in aluminum tape for RF

shielding

• Closed forged steel eye bolts, ¼-20

threaded rods with lock nuts to secure bay

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• 3D printed from SLA material
• Attaches to sled by screws on top case
• Wires protrude through holes in the side and

battery clips go on through holes in the front

• Easily assembled and reusable
• Easy to manufacture
• 3D printed
• Attaches to bulkhead by screws
• A sure secure fit
• Allows for easy reuse and relocation of

rotary switches

• Easy to manufacture and assemble

Batteries and Switches Cases

Battery Case Switch Case

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Altimeters

Altimeter Price Dimensions Weight Altitude Accuracy Operating Voltage PerfectFlite Stratologger CF $58.80 2"L, 0.85"W, 0.5"H 0.38 oz ± 0.1% 9V nominal (4V to 16V) Missile Works RRC2+ $44.95 2.28"L, 0.925"W, ~0.5"H 0.35 oz Not given 9V(3.5VDC- 10VDC) Missile Works RRC3 $79.95 3.92"L, 0.925"W, 0.563"H

• 0. 59 oz

Not given 9V(3.5VDC- 10VDC) 36

• Location
• Fixed to middle airframe, below the recovery bay
• Provide easy access to turn on while on launch pad
• Components
• 3D printed custom housing module
• Eggfinder Tracking System, Openlog, and Power Stick
• 7.4V LiPo battery pack
• Shurter rotary switch

GPS

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Electronics Wiring

• Two redundant systems
• Each have own battery
• Each have own switch
• Drogue charges
• Primary: Apogee
• Backup: Apogee + 1s
• Main charges
• Primary: 500 ft
• Backup: 500 ft + 1s

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Parachute Overview

Parameter Main Parachute Drogue Parachute Name Iris Ultra Standard 120” SkyAngle Classic II 32” Shape Toroidal Extended Panel Cd 2.2 1.14 Diameter 120 in 32 in Weight 36 oz 7.7 Packed Length (6” airframe ~ 10 in ~ 7 in Shroud Line Strength 400 lbf x 12 lines 950 lbf x 3 lines Cost $402.00 $41.25

Main Drogue

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Attachment Hardware

Swivels 1500 lbf Prevents tangling of shroud lines Quick Links 1500 lbf Allows for easy removal of shock cords/parachutes Eye Bolts 1300 lbf Provides attachment point to bulkheads

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Table of Contents

1. Vehicle Overview …………………………………………………………………………………………. 2. Subscale Launch ………………………………………………………………………………………..... 3. Apogee Targeting System …………………………………………………………………………….. 4. Recovery Subsystem ……………………………………………………………………………………. 5. Mission Performance Predictions ……………........................................................... 6. Payload Overview ……………………………………........................................................... 7. Requirements Compliance Plan ………………........................................................... 8. Logistics ……………………………………………………………………………………………………….. TBD TBD TBD TBD TBD TBD TBD TBD

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Apogee Targeting Procedure

Target Apogee: 5100 ft Methodology

• Select motor that achieves apogee 5300 ft – 6000 ft
• Apply ballast so that apogee is reduced to 5200 ft
• Use ATS to apply drag and fine tune altitude to 5100 ft

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Motor Selection

Parameter Value Name AeroTech L1420 Propellant APCP Peak Thrust (lbf) 408 Average Thrust (lbf) 319 Total Impulse (lbf-s) 1035 Duration (s) 3.2 Apogee Range (ft) 5200-5600

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Flight Profile for AeroTech L1420

Parameter Value Apogee (ft) 5101 Thrust to Weight Ratio 6.59 Rail Exit Velocity (ft/s) 69.98 Maximum Velocity (ft/s) 581.18 Drogue Terminal Velocity (ft/s) 81.73 Main Terminal Velocity (ft/s) 13.83 Descent Time (s) 85.76 Wind Speed (mph) Ballast (oz) 31 44

Drift Calculations

Wind Speed Open Rocket Drift Calculated Drift 1217 5 1331 629 10 1504 1258 15 1712 1872 20 2004 2516

𝐷𝑏𝑚𝑑𝑣𝑚𝑏𝑢𝑓𝑒 𝐸𝑠𝑗𝑔𝑢 = 𝑢𝐸𝑤 𝑢𝐸 = 89.4 𝑡 𝑤 = 𝑥𝑗𝑜𝑒 𝑡𝑞𝑓𝑓𝑒

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Kinetic Energy

Section Mass (oz) Kinetic Energy (lbf-ft) Upper Section 202.9 43.02 Middle Section 210.2 44.56 Lower Section 281.4 59.66 Total Landing 694.5 N/A

𝐿𝐹 = 1 2 𝑛𝑊2 𝑊 = 2𝑛𝑕 ρ𝐵𝐷𝐸

Middle Section Upper Section Lower Section 46

Static Stability

Case CG Location (in from tip) CP Location (in from tip) Stability Margin (cal) No Motor 60.05 80.96 3.39 AeroTech L1420, min ballast (0 oz) 67.64 80.96 2.16 AeroTech L1420, max ballast (36 oz) 65.28 80.96 2.54

Min Ballast Max Ballast

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Dynamic Stability

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Table of Contents

1. Vehicle Overview …………………………………………………………………………………………. 2. Subscale Launch ………………………………………………………………………………………..... 3. Apogee Targeting System …………………………………………………………………………….. 4. Recovery Subsystem ……………………………………………………………………………………. 5. Mission Performance Predictions ……………........................................................... 6. Payload Overview ……………………………………........................................................... 7. Requirements Compliance Plan ………………........................................................... 8. Logistics ……………………………………………………………………………………………………….. TBD TBD TBD TBD TBD TBD TBD TBD

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UAV Design Options

Fixed Wing (Alternative) Caged Quadcopter (Selected)

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UAV Design Comparison

Characteristic Caged Quadcopter Fixed Wing Weight Heavy Light Position Control Fine Poor Size Moderate Large Efficiency Low High Crash Recovery Success High Low Motor Failure Recovery Success Low High Cost High Low Decision Selected Not selected 51

UAV Changes

• Simplified Cage Design (Increased Rigidity and Manufacturability)
• Off the Shelf Frame (Lower Cost and Shorter Lead Time)
• Same Electronics and Beacon Drop System

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UAV Design Overview

• Off the Shelf Frame (from EMAX)
• Compact Caged Structure
• No Moving Parts on Cage
• Manufacturing
• 3D Printed Cage Rings
• Retrofit Cage onto Motor

Mounts

• Mount Beacon

Deployment System to Bottom of Electronic Stack

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UAV Electronics Overview

• Hobby Grade Components
• Camera: Runcam Swift
• Low Mass, Low Power
• Motors: EMAX 1106
• High Power, Compact
• Video Transmitter: TBS Unify Nano
• Efficient, Compact
• Flight Controller: HGL RC F440
• Integrated ESC
• Low Mass, High Amp ESC

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UAV Schematics

• Simple Integration of All Systems
• Assembly:
• Solder All Major Subcomponents

to Flight Controller

• Attach Camera and Bracket to

Top Flight Controller Mounts

• Mount Video Transmitter to Top
• f Flight Controller Using 3M

Tape

• Mount Electronic Stack to Frame

Mount Holes

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Deployment Process

• Preflight: Establish Link, Test Systems
• Post flight: Visually Verify UAV bas

exited vehicle

• Arm UAV: Startup Motors and Prepare

for Flight (Exit Low Power State)

• Reorient UAV to Upright Position
• Takeoff and Fly To Tarp
• Deliver Beacon
• Land and Disarm

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UAV Beacon Deployment

• Micro Linear Servos provide actuation
• Extremely light servo (1.5g) increases

range

• “Hook” locks beacon into place
• Beacon remains locked in place even

without power

• Beacon provides counterweight for

drone in cage

• No Major Changes to Beacon

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UAV Ground Station

• Simplified Video Receiver Setup
• UAV Control: Spektrum DX8 (2.4Ghz)
• Video: Diversity FPV Receiver (5.8Ghz)
• Multiple Antennas Provide Failover
• Video Transmitted from Drone to Goggle

Receiver

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Payload Deployment System Overview

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UAV Deployment System-Mechanical

• Sub-coupler for electronics bay:

Blue Tube & ¼”-20 High-Steel threaded rods

• Electronics Tower: ACRYLITE

(Acrylic) and aluminum corner brackets

• ¼”-16 Stainless Steel Lead

Screws and Nuts

• ¼” to 5 mm Set Screw Shaft

Coupler

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UAV Deployment System-Electrical

• Power Systems: G7 3S 2200mAh

Si-Graphene Battery & 9V Battery

• Control & Communications

Systems: DC Motor + Stepper FeatherWing & Adafruit Feather M0 with RFM95 LoRa Radio - 900MHz - RadioFruit

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UAV Deployment System-Motors

• Stepper Motor: Lin

Engineering 4209M- 01S

• Encoder: E5 Optical

Differential Encoder with Index

• 10- Pin Latching

Connector

• ~20 oz-in stall

torque under 12 V source

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Table of Contents

1. Vehicle Overview …………………………………………………………………………………………. 2. Subscale Launch ………………………………………………………………………………………..... 3. Apogee Targeting System …………………………………………………………………………….. 4. Recovery Subsystem ……………………………………………………………………………………. 5. Mission Performance Predictions ……………........................................................... 6. Payload Overview ……………………………………........................................................... 7. Requirements Compliance Plan ………………........................................................... 8. Logistics ……………………………………………………………………………………………………….. TBD TBD TBD TBD TBD TBD TBD TBD

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NASA Derived Requirements

Requirements Section Met In Progress Comments General 12/13 1/13 STEM-Engagement on pace to complete Vehicle 20/24 4/24 Verification pending full-scale flight and testing Recovery 9/13 3/12 Verification pending full-scale flight and testing Payload 12/14 2/14 Verification pending launch day activities Safety 5/5 0/5 Met through procedures

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Requirements Section Met In Progress Comments Vehicle 4/5 1/5 Pending full-scale flight and testing Recovery 2/2 0/2 Complete Payload 3/3 0/3 Complete

Team Derived Requirements

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Recovery Testing plan

• Recovery bay pressure seal
• Ensure accurate altimeter reading
• Electric match wiring
• Verify electrical continuity and correct charge deployment order
• Ground ejection tests
• Verify black powder amount
• Standby readiness battery life test
• Ensure sufficient battery life

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ATS Testing plan

• Deployment/retraction of flaps test
• Verify proper actuation while under flight loads
• Flap extension accuracy test
• Verify proper actuation for a given input
• Sensor Integration testing
• Verify that all sensors send data to the ATS control architecture
• Code speed and stability testing
• Verify that code is robust and runs sufficiently fast
• Standby readiness battery life test
• Ensure sufficient battery life

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Payload Testing plan

• Flight duration test
• Ensure sufficient flight time
• IMU accuracy test
• Ensure accuracy and precision of IMU to allow for UAV reorientation
• UAV rotation test
• Verify UAV reorientation capability
• Deployment test
• Verify proper UAV deployment
• Deployment signal range test
• Ensure sufficient deployment signal range

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Table of Contents

1. Vehicle Overview …………………………………………………………………………………………. 2. Subscale Launch ………………………………………………………………………………………..... 3. Apogee Targeting System …………………………………………………………………………….. 4. Recovery Subsystem ……………………………………………………………………………………. 5. Mission Performance Predictions ……………........................................................... 6. Payload Overview ……………………………………........................................................... 7. Requirements Compliance Plan ………………........................................................... 8. Logistics ……………………………………………………………………………………………………….. TBD TBD TBD TBD TBD TBD TBD TBD

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Budget

Category Amount Percent Total Travel $3,890.00 34.7 Launch Vehicles $3,323.78 29.7 Payload $2,065.00 18.4 Avionics $1,053.92 9.4 Recovery $475.23 4.2 Reserve $400.00 3.6 Total $11,207.93 100.0 $3,890 $3,324 $2,065 $1,054 $476 $400 Travel Launch Vehicles Payload Avionics Recovery Reserve 70

Funding

Category Amount Percent Total Allocated Budget $5,837 37.7 Crowdfunding $3,933 25.4 Sponsorships $1,500 9.7 CMU College of Engineering $1,200 7.8 CMU Mech. Eng. $1,000 6.5 Drone Club $750 4.8 Member Dues $750 4.8 CMU Physics $500 3.2 Total $15,470 100.0 $5,837 $3,933 $1,500 $1,200 $1,000 $750 $750 $500 Allocated Budget Crowdfunding Sponsorships CMU College of Engineering CMU Mech. Eng. Drone Club Member Dues CMU Physics 71

Educational Engagement

15 75 60 45 25 200

YMCA Burrel/Huston School Environmental Charter School CMU Children's School CMU Homecoming Moon District School

47 10 143

CMU Children's School CMU Homecoming Remaining

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Mechanical Team Timeline

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Avionics Team Timeline

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Payload Team Timeline

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Thank you,

Questions?

Special thanks to John Haught, Prof. Satbir Singh, and Prof. Mark Bedillion! 76