CRITICAL DESIGN REVIEW (CDR)Charger Rocket WorksUniversity of Alabama in HuntsvilleNASA Student Launch 2013-14Kenneth LeBlanc (Project Lead)Brian Roy (Safety Officer)Chris Spalding (Design Lead)Chad O’Brien (Analysis Lead)Wesley Cobb (Payload Lead)
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Prometheus Flight Overview
Payloads Here
Payload DescriptionNanolaunch 1200 Record flight data for aerodynamic coefficients
Dielectrophoresis Use high voltage to move fluid away from container walls
LHDS Detect and transmit live data regarding landing hazards
Supersonic Coatings Test paint and temperature tape at supersonic speeds
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Technology Readiness Level
http://web.archive.org/web/20051206035043/http://as.nasa.gov/aboutus/trl-introduction.html
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Outreach• Adaptable for different ages and
lengths• Beginning outreach packet with
Elementary School• Building the program from the ground up
with school advisers• Supporting activity
• Water Rockets• Completed
• Science Olympiad• 102 Middle School• 54 High School
• Scheduled• Challenger Elementary
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On Pad Cost
Payload
Hardware
Recovery
Propulsion
$- $10,000.00 $20,000.00
$626.98
$506.94
$408.00
$820.91
$2,026.98
$15,506.94
$408.00
$15,820.91
Theoretical: $33.762Actual: $2,362
Cost
Syst
em
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ANALYSIS
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Analysis Responsibilities• Fin Flutter Analysis• RockSim/Open Rocket Trajectory Simulations• MATLAB 3DOF Simulations• Monte Carlo Simulations• FEA Analysis using MSC PATRAN and NASTRAN• CFD Analysis using CFD-ACE+
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Flight Trajectory• Max Altitude: 15800 ft• Max Velocity: 1600 ft/s, Mach: 1.45• Acceleration: 40 G
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Flight Trajectory
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Flight Trajectory
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Vehicle Aerodynamics – M4770
• Static Margin – 1.61• CP – 92 in• CG – 84.4in
• Thrust To Weight • Max Thrust – 1316 lbf T2W: 40• Average Thrust – 1073 lbf T2W: 33.5
• Exit Rail Velocity – 122 fps
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Final Motor Selection - CTI M4770-P
• ISP – 208.3s• Loaded Weight: 14.337 lb• Propellant Weight: 7.3 lb• Max Thrust: 1362 lbf
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Monte Carlo Analysis
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Proof of Randomization in Inputs
• Shows output consistency overmultiple sets of simulations.
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Drift Analysis
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Variation in Flight Time
• Time variance directlyaffects the radial landingdistance.
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CFD - Critical Mach Number
*Steady state values Indicated by color maps
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CFD – Aerothermal Heating
*Steady state values Indicated by color maps
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CFD - Drag vs Mach Plot
• Uncertainty with Mach < 0.5• Inadequate convergence in low Mach Regime
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Plan B Motor: CTI-L890
Cross Wind 5mph 10mph 15mph 20mph 25mph
Drift 900ft 1950ft 3050ft 4250ft 4700 ftMain Deployment
Altitude 750ft 750ft 750ft 750ft 500ft
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Recovery System
• Single Separation Point• Main Parachute
• Hemispherical• 12 ft • Cd 1.2• Nylon
• Drogue Parachute• Conic• 2.5 ft• Cd 0.71 (experimentally determined)• Nylon
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Recovery System Deployment Process
• Stage 1• 2 seconds after apogee • nose cone separates• release the drogue
• Stage 2• 2.1
• Drogue attached via tethers.• 2.2
• A black powder charge separates the tethers
• Stage 3• Main parachute pulled from
deployment bag
Eye bolt
L.H.D.S
Tethers
Black Powder Charge
Drogue
Main Parachute InDeployment bag
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Stage 1: Drogue DeploymentStage 2.1
Stage 2.2
Stage 3
Deployment Process
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Energy and Velocity at Key Points
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Sewing Technique• Seam Type: French Fell • Vent Hole supported with double stitched bias tapes• The bottom edge hemmed
• Prevent fraying• Increase durability
Stich Seam Cross Section
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Subscale Drogue• Flight Test
• Built by team• First attempt
• Subscale Data• Perfect flight Altimeter• Cd of 0.71• 27.5” Diameter
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Construction Materials
•Swivel ultimate load:1045 lbs•The nylon line anchor points ultimate load: 120 lbs per strap•The eyebolt ultimate load: 500 lbs
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DESIGN
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Hardware Team responsibilities:
• Vehicle design
• Testing and verification of
materials and components
• Vehicle construction
• Interfaces
Design Details:
• 34lbs
• 40Gs acceleration
• Geometric similarity to NASA
Nanolaunch protoype
• Nanolaunch team requested
maximum use of SLS printed
titanium
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Interfaces (1)# Component Interface Method Load Locations1 Pitot probe Threaded to nosecone shaft Tension from pitot shaft, compression
from nose cone, aerodynamic forces
2 Nosecone Slip fit with Shear Pins Compression from pitot probe and slip ring, aerodynamic forces
3 Nosecone Payload
Threaded to nosecone shaft Acceleration forces, passed through nose cone shaft
4 Nosecone shaft Threaded to pitot probe Tension loads between the nose cone bulkhead and pitot probe, compression/ tension from payload acceleration forces
5 Nosecone Bulk head
Slipped over payload shaft Tension from payload shaft/ ring nut
Nose cone slip ring
Slipped into body tube with shear pins, retained to nose cone with nose cone shaft
Compression from nose cone and body tube, aerodynamic forces
6 Nosecone shaft nut
Threaded to nosecone shaft Tension from payload shaft
7 Recovery package Shock cord / knot / ring nut Tension from ring nuts, aerodynamic forces
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Interfaces (2)8 Payload Slipped onto payload shaft/
constrained between nutsAcceleration forces, passed through payload shaft
9 Lower slip ring Held in compression between body tube sections with payload shaft
Compression from upper and lower body tubes, aerodynamic forces
10 Payload shaft Threaded to motor case / lower bulk head / ring nut
Tension between bulkheads and ring nut, compressive and tensile forces from payloads under acceleration
11 Centering ring Slipped onto payload shaft/ constrained between nuts
Radial location of motor case; negligible forces
12 Motor case Threaded to payload shaft Outside manufacture; loaded in designed manner
13 Fins / Fin brackets Bolted to lower body tube/ T nuts inside body tube
Aerodynamic and acceleration forces, resulting tension from body tube
14 Thrust ring Held in compression between motor case and body tube
Compression from motor case
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Thrust Ring
• Printed titanium
• Analyzed with FEA
• Significantly stronger than
required
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Fin Assemblies
• Modified significantly since PDR due to
updated geometry from Nanolaunch
team (bolted instead of epoxied)
• Easier to inspect and verify
• Fin replacement in the field now
possible
• Moderate weight penalty compared to
original design.
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Body Tube
• Carbon composite
• FEA, destructive testing and
hand calculations done to assess
strength
• Large margin of safety and low
weight
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Payload Shaft
• 7075-T6 Aluminum threaded shaft
• Preloaded in tension
• FEA and hand calculations show significantly over strength requirements
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Payload Shaft Load Paths
• Carries thrust loads into payloads and recovery forces into lower rocket, as
well as providing assembly method for payloads, body tubes and recovery
harness
• Red Arrow indicates motor loads from thrust ring through body tube
• Green arrow indicates motor loads passed through payloads
• Blue arrow indicates recovery forces passed through payload shaft
• Orange arrow indicates motor case retention force
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Coupler Rings
• Machined aluminum
• Aft coupler retained by
payload shaft preload
• Fore coupler retained by
nose cone shaft and shear
pins
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Nose Cone Assembly
• All components retained by shaft similar to payload shaft
• Carbon fiber nose cone shroud and bulkhead
• Contains pitot pressure and accelerometer/ gyro data package
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Pitot Probe
• Allows measurement of static
pressure along with supersonic
AND subsonic total pressure
• Unique and original design which
could only be made with 3D
printing techniques
• Helps fulfill our Nanolaunch
request to explore selective laser
sintering in original ways.
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Structure Testing• Carbon fiber dog bones
• Loaded in tension • Verify tensile strength of materials
• Tubes• Loaded in compression• Verify compressive strength of
representative structures of body tube
• 45/45 Sleeve• 0/90 Wrapped
• Parachute Material• Loaded in tension • Verify parachute material and
seam strength
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Tension Results
Test Sample Failure Load (lbf) Max Extension (in)1 1951.4 0.0862 1785.3 0.0743 1781.8 0.0684 1732.8 0.0645 1820.3 0.084
Average 1814.3 0.075Standard Deviation 82.7 0.010
Dog Bones
0.00E+001.00E-022.00E-023.00E-024.00E-025.00E-026.00E-027.00E-028.00E-029.00E-02
0 500 1000 1500 2000
Exte
nsio
n (in
)
Load (lbf)
Average Load vs. Extension
Fractures
FracturesDog bones
• Verified Strength Requirements• Fractures showed uniformity in
the angle of the fibers• Calculated Young Modulus to
be 309 ksi
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Compression ResultsFractures
Test Sample Failure Load (lbf) Max Compression (in)Sleeve 6226.1 0.139
Wrapped 8093.5 0.070
Tubes
0100020003000400050006000700080009000
40 50 60 70 80 90 100
Load
(lbf
)
Time (s)
Tube Compressive Strength
Tubes• Wrapped tube holds the most
force• Fractures showed uniformity in
the angle of the fibers• Failure Load: 8094.5 (lbf)
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Parachute ResultsSeam Test
• Seam failed before material• Breaking of seam occurred at
35 lbf• Narrow sample failed at seam
due to edge effects
0
5
10
15
20
25
30
35
40
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0 20 40 60 80 100 120 140
Load
(lbf
)
Time (s)
Parachute Strength
Test Sample Failure load (lbf) Max Extension (in)1 35.71812 1.792 39.05464 1.87
Parachute
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Structure Testing Conclusions
Verified Requirements • Strength• Thickness• Fiber Angle • Fabrication
Future Testing• Recovery system• Electronic payload• Verification of flight hardware• Flight testing completed rocket
Test Sample Failure Load (lbf) Max Extension (in)1 1951.4 0.0862 1785.3 0.0743 1781.8 0.0684 1732.8 0.0645 1820.3 0.084
Average 1814.3 0.075Standard Deviation 82.7 0.010
Dog Bones
Test Sample Failure Load (lbf) Max Compression (in)Sleeve 6226.1 0.139
Wrapped 8093.5 0.070
Tubes
Test Sample Failure load (lbf) Max Extension (in)1 35.71812 1.792 39.05464 1.87
Parachute
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Vehicle Requirements
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PROCEDURES
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Testing ProceduresTest
Requirement Identified
Develop Operating
Procedures
Review of Procedures
by PRC Staff
Procedure Approval by
PRC Director
Identify Red Team
Members for Test
Review of Operating
Procedure with Red Team
Approval of Red Team Members
Testing
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Subscale Testing and ResultsSub-Scale Flight Test Matrix
Type of Test Test Goals Results
Sub-Scale Flights Verify the vehicle stability margin and flight characteristics. Successful (2/8/14)
Flight ElectronicsEnsure that payload records proper data and that launch detect functions properly.
Partial Success (2/22/14)
Recovery System Hardware
Test hardware that will allow for a single separation dual deploy setup in full-scale vehicle.
Partial Success (2/22/14)
Parachute DesignVerify construction techniques are adequate and determine effective drag coefficient.
Success (2/22/14)
High Acceleration Flight (40+ G’s)
Ensure that avionics will survive launch forces of full-scale. Not Yet Tested
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Recovery Hardware Testing
• Problems with deployment bag.• Successful proof of concept flight for parachute design.• Successful test of separation charges.
Deployment Bag Failure Point
CRW Built Parachute
Separation Charges
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Subscale Flight Data
• Apogee: 1,573 feet AGL.• Max Velocity: 279 ft/s.• Time of Flight: 63.9 seconds.• Motor: CTI I-205.• Recorded Using a PerfectFlite SL100
• Apogee: 4,156 feet AGL.• Max Velocity: 597 ft/s.• Time of Flight: 128.6 seconds.• Motor: Aerotech I-600.• Recorded Using a PerfectFlite SL100
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PAYLOADS
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Nanolaunch Experiment Overview• Calculating Aerodynamic Coefficients
• Pitching moment Coefficient• Drag Coefficient• Measure base pressure
• Two separate sensor packages• Accelerometers• Gyroscopes• Pressure sensors
• Similar not identical• Nosecone
• Pitot probe• 60 PSI• 100 PSI
• Near CG• Base pressure sensors
• 30 PSI• Designed for future use
CG Configuration
ADXL345
ADXL377
L3GD20
30 PSIPressure Sensors
ADC
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Nanolaunch Testing• Sensor Output
• Ground tests - Breadboard• Calculated Pressure Sensor Gain• Tested Code Functionality • Sampling at 48 Hz per sensor
• Subscale Flight – Data Extracted• Full Scale flight to Come
• Will Include Pressure Sensors
• EMI Testing• Test for EMI interference with
sensors• Ground tests
Subscale Payload Bay
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Nanolaunch Payload Test Matrix• Tested Methodically• Successful Payload Data Extraction During Subscale
Launch
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Nanolaunch Success Criteria• Objectives: Meet Team/NASA SLI Requirements and
Verify Those Were Met
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Outcomes and Nanolaunch Path Forward
• Outcomes:• Successfully Extracting Data• Preliminary Data/Results
• Rocket Angular Velocity: Will be Calculated Based on Sign Change in Accelerometer Data
• Path Forward• Record More Launch Data for Data Comparison• Create Data Buffer( To keep 30 seconds of data prior to launch
detect)• Calibration of Sensors• Raise the ADXL345 Accelerometers to 16G setting.• Incorporate Amplified Pressure Sensors and ADC Into Circuit
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Dielectrophoresis (DEP)• Fluid manipulation
• Electric field• Peanut oil
• Voltage• Voltage squared drives strength of electric field
• Fluid• Dielectric constant determines fluid interaction
• Electrode geometry• Gradient of electric field depends on geometry
Uniform Electric Field
Positive Region Negative Region
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Experimental Changes
• Electrode configuration: from parallel electrodes, to annular electrodes
• Voltage increase from 7kV to ~12kV
2012-2013 Configuration
2013-2014 Configuration
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DEP Testing• EMI Testing
• Test next to flight ready recovery system• Minus gunpowder
• Test next to Nanolaunch• Test and Prove design
• Test revised circuit• Structure tests
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DEP Success Criteria Requirement Success Criteria Verification
Microgravity environment Reach apogee of flight to experience microgravity
environment
Retrieve accelerometer data determine duration of
microgravity environment Manipulate fluid with electric
field Noticeable collection of fluid
around central electrode Retrieve camera and accelerometer data
Perform experiment without interfering with other payloads
Reliable data collection from all payloads adjacent to DEP
Rigorous preflight testing .Post flight analysis of data.
Recoverable and reusable Fluid containers intact. No electrical shorts. Functional
electronics
Recover the payload. Return to flight ready state with no
repairs needed.
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Supersonic Paints and CoatingsUrethane Epoxy
Epoxy
•Urethane • Excellent retention• Abrasion resistant • Smooth Coating
•Epoxy Primer• Low film build• Excellent adhesion• Rough Coating
•Thermal tape• 3-5 second reaction time• Changes color at specific
temperatures• Excellent Adhesion
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SPC Testing• Oven Testing for Temperature tape
• Calibration of tape• Temperature sensitivity • Reaction time
• Flight Test• Subscale Test Flight• Full scale test launch
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Success Criteria of Paints and Coatings
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Landing Hazard Detection• Beaglebone
• Camera cape• C++ libraries• Established knowledge base
• 3 Methods of Analysis• Color detection• Edge detection• Shadow analysis
• Grid analysis• Faster processing
• Orientation• Use accelerometer to filter images of the ground
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Radio• RF Module: XBee-PRO XSC S3B
• 900 MHz transmit frequency• 20 Kbps data rate• 9 mile LoS range• 250 mW transmit power• 3.3 VDC supply voltage• 215 mA current draw• 1.5+ hr battery life at max sensor sample rate• Laptop ground station
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GPS Tracking• GPS Module: Antenova M10382-Al
• GPS lock from satellites• Transmits data through XBee RF module• 8 ft accuracy with 50% CEP• 3.3 VDC supply voltage• 22 to 52 mA current draw
• Redundant GPS Unit: “Tagg Pet Tracker”• Supported by Verizon cell network• Smartphone based ground station• 25 ft accuracy with 95% confidence• Self-contained power source• 3.5+ days battery life
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LHDS Testing• Test Flights
• Full scale only• Alter method for different launch field
• Bench Test• White wall simulates salt flats• Colored paper as “hazards”• Google Map images
Hera Launch FieldManchester, TN
Bonneville Salt Flats, UT
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LHDS Success Criteria
Requirement Success Criteria Verification
Transmit LHDS data in real time to a ground station.
Data is sent from RF module aboard rocket to ground station
without loss or corruption.
Transmitted data is received by ground station. Data is verified using either Checksums or post-
flight data comparison.
The payload shall be recoverable and reusable.
Recover the RF module and reuse it.
The RF module is recovered and can be launched again on the
same day.
Transmit live GPS DataRF module transmits live GPS
data from the GPS module to the ground station.
GPS location of the rocket is received by the ground station.
The electronic tracking device shall be fully functional during
the official flight at the competition launch site.
GPS data is sent through RF module aboard the rocket to the
ground station during the competition launch.
GPS location data from the rocket is received by the ground
station during the official flight at the competition.
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THANK YOU
QUESTIONS?