Flight Readiness Review - University of Evansville · Full Scale Flight Narrative Simulation Launch Day Conditions Quick Links Ballast (lb) Simulated Apogee (ft) Actual Apogee (ft)

NASA’s Student Launch Initiative :

Flight Readiness Review

Payload:

Fragile Material Protection

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Design Overview Full Scale Flight Recovery & Payload Testing & Procedures Requirement Verification

Agenda

1. Design Overview

2. Full Scale Flight

3. Recovery & Payload

4. Testing & Procedures

5. Requirement Verification

I. Conditions

II. Narrative

III. Analysis

I. Launch Vehicle

II. Payload

3

Overview


Final Launch Vehicle and Payload Dimensions

4


Key Design Features

Carbon Fiber Airframe

Fragile Materials Handling

Middle-Out Dual Deployment

L850W

5


Final Motor Choice & Retention System

Manufacturer AeroTech

Make L850W

Total Impulse 3695Ns

Type Reloadable

Max Thrust 1185 N

Weight (Empty) 3.54 lbs

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• Using the AeroPack 75mm P Retention System


Weight Breakdown

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Aerodynami

cs

5.96

17%

Electronic

Payload

1.91

6%

Main

Payload

5.25

15%

Misc

1.00

3%

Propulsion

10.68

31%

Recovery

9.79

28%

Predicted Weight with Motor* 34.6 lbf

Actual Weight with Motor* 35.0 lbf

*weight without ballast


Full Scale Flight Launch Day Conditions

• Elizabethtown, KY

• Temperature – 59 oF

• High Humidity

• Rain off and on

• Average Wind Speed – Variable

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Full Scale Flight Narrative

Simulation Launch Day

Conditions Quick Links Ballast (lb)

Simulated

Apogee (ft)

Actual Apogee

(ft)

1a – Baseline No Heavy 2.0 5,005 -

Flight 1 Yes Heavy 2.0 4,967 4,913

Flight 2 Yes Heavy 0.0 5,322 4,795

Flight 3 Yes Light 1.5 5,326 5,291

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Weight of Heavy Quick Links = 1.565 lb Weight of Light Quick Links = 0.478 lb

Actual vs OpenRocket Analysis

0

1000

2000

3000

4000

5000

6000

0 20 40 60 80 100 120 140 160

Alt

itu

de

(ft

)

Time (s)

Actual Altitude (ft)

OpenRocket Altitude (ft)

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0%

2%

4%

6%

8%

10%

12%

0.00

1000.00

2000.00

3000.00

4000.00

5000.00

6000.00

0 20 40 60 80 100 120 140

Pe

rce

nt

Erro

r (%

)

Alt

itu

de

(ft

)

Time (s)

Regression Altitude (ft)

Percent Error

Valid between 0.55 and 113 seconds

Final Flight Stability

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69.47 in

84.31 in

Measured Static Stability of 2.70


0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0

1000

2000

3000

4000

5000

6000

0 2 4 6 8 10 12 14 16 18 20

Stab

ility

(ca

l)

Alt

itu

de

(ft)

Time (s)

Altitude (ft) Stability margin

Final Flight Stability (cont’d)

• Stability Off-Rail = 2.143 12


Rail Exit Velocity

Time to Exit Rail

(s)

Velocity at Rail Exit

(feet per second)

Simulation 1 0.44 64.5



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Mach Number

Mach Number

Simulation 1 0.50

Simulation 2 0.53

Simulation 3 0.53

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Thrust to Weight Ratio: 5.34:1

Altitude at Different Wind Speeds

Third Flight Configuration

Wind Speed

(mph)

Predicted Altitude

(ft)

0 5,290

5 5,327

10 5,334

15 5,316

20 5,297

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Recovery

• Dual-deployment • Coupling tube houses recovery electronics

• Drogue above, main below

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Recovery – Initial Descent

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Parachute Fruity Chutes CFC-24

Event Altitude Apogee

Redundancy 2-second delay

Descent Velocity 76.5 ft/s

Kinetic Energy 1249 ft-lbf

http://fruitychutes.com/parachute_recovery_systems/classic_elliptical_chutes.htm


Recovery – Final Descent

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Parachute Fruity Chutes IFC-96

Event Altitude 750 ft

Redundancy 650 ft

Descent Velocity 14.5 ft/s

Kinetic Energy 41.0 ft-lbf

http://fruitychutes.com/parachute_recovery_systems/iris_ultra_parachutes.htm


Recovery – Kinetic Energy (ft-lbf)

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Bow Body Tube Coupling Tube Aft Body Tube

Ascent 173,100

Initial Descent 1,141 1,249

Final Descent 41.0 10.88 33.9


Recovery – Drift Distance

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Wind Speed (mph) Lateral Distance (ft)

0 9

5 299

10 640

15 1043

20 1492


Recovery – Construction

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Recovery – Construction

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Recovery – Performance

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• First Flight – As Designed • Two events with 4 charges total

• Second Flight – As Designed • Two events with 4 charges total

• Third Flight – Malfunction • Premature deployment of main parachute

• Over-sized drogue charges

Recovery – Performance

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Flight Wind Speed (mph) Predicted Drift (ft) Measured Drift (ft)

1 11.5 761 1705

2 13.8 946 2085

3 13.8 946 5347


Recovery – GPS Tracking

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Payload

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Payload

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Payload

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Testing Plan

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Parachute Ejection Testing

Sub-Scale Test

Parachute Testing

Bulkhead Payload

Altimeter

Wind Tunnel

Full Scale Test

Testing – Parachutes Ejection Test

• Ensures working electronics and enough force to shear the shear pins

• Horizontally mount the rocket body • Padding to catch the end being tested

• 8 successful tests needed to be acceptable • 4 for each body tube

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Testing – Parachutes Ejection Test (Results)

Signal Number of Tests

Number of

Failures

Notes

Primary Main 2 0

Primary Drogue 2 0

Backup Main 2 0

Backup Drogue 3 1 Wiring Issue 31


Testing – Sub-Scale Model

• Ensures all components work as a system, not just individually

• Two flights were done to test the model • Main parachute did not deploy on Flight 1

• More black powder for Flight 2, and a successful landing

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Testing – Parachutes Force

• Determine force upon main parachute deployment

• Original Plan: • Create apparatus for simulated deployment conditions

• Mount parachute to electronic force meter

• Pack parachute into tube segment

• Mount apparatus to vehicle, accelerate to 50 mph

• Deploy parachute and analyze force data

• Outcome: • Acceleration data from the scoring altimeter

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Testing – Parachutes Force (Results)

Flight # Maximum Force (lbf)

1 198.8

2 95.0

3 206

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Testing – MTS Bulkhead

• Determine maximum force allowed by mounting hardware

• Create apparatus for simulated deployment conditions • Assemble bulkhead with U-bolts and nuts

• Epoxy bulkhead to spare body tube segment

• Use tensile testing machine to stress the hardware until failure

• Analyze force response to determine acceptable stress

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36



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Testing – MTS Bulkhead (Results)

Maximum Force 1555 lbf 2253 lbf

Component Failure Epoxy Epoxy

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Testing – Altimeter

• Ensure the GPS works on the main scoring altimeter

• The altimeter will be attached to a drone and flown around • Allows us to check the GPS location, and the live feed

• Recovery altimeters were also tested to check deployment altitude • All three altimeters were tested together

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Testing – Payload

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• Determine filler material for the inner cylinder

• Payload will be subjected to Charpy impact tests • Drop Testing canceled due to lack of repeatability

• Unable to control the impact angle

• Accelerometer placed inside the payload

• The payload along with the filler material will be varied

• Using the results with the decision matrix will help us select a final filler material

Testing – Payload (Results)

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Fill Material

Cotton Filling Shredded Paper Paper/Cotton mix Base Value

Acceleration

(counts/g) average

of x,y and z

directions.

11444 2452 N/A 11643

Percent reduction

from base1.7 78.9 N/A N/A

Break y/n? Fill Material

Cotton Filling Shredded Paper Paper/Cotton mix no fill

2 large incadescent bulbs no no no no

2 candelobra bulbs no no no yes

Fragile material glass sheet no no no yes

egg 1/2 power swing no no no yes

egg full power swing no no no yes

egg full power swing double

impact no no no yes

Testing – Payload (Results)

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-40000

-30000

-20000

-10000

0

10000

20000

30000

40000

1430 1435 1440 1445 1450 1455 1460 1465 1470 1475

Acc

eler

atio

n (

cou

nts

/hz)

Time Step 4 Hz

X Y Z

Testing – Wind Tunnel

• A thorough uncertainty analysis has been done

• Design of experiment is completed • Pushed back due to concerns of validity of equipment

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Testing – Full Scale Model

• Three flights were performed

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Apogee Did the Payload Survive?

Flight 1 4913 feet Yes



Launch Operation Procedures & Checklists

• Parts Checklist

• Motor Preparation Checklist

• Recovery Preparation Checklist

• Final Assembly Inspection

• Launch Pad Configuration and Inspection

• Ignitor Installation Checklist

• Launch Procedures Checklist

• Troubleshooting Procedures

• Post-Launch Inspection

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Launch Procedures

• Upon Arrival • Ensure Safe Working Area

• Check Safety and Readiness of Team Members and Bystanders

• Inspect Team for Proper PPE

• Transportation • Inspect Launch Pad for Flight Readiness

• Carefully Transport Rocket to Launch Pad

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*For further detail regarding launch procedures and pre/post-launch inspections, see individual subsection checklists within Launch Operations Procedure section of FRR Report.

Launch Procedures

• Test • Launch Vehicle’s Ability to Separate

• Electronics Functionality – Altimeter and GPS

• Inspection for Flight Readiness • Body Tube

• Fins

• Payload Configuration

• Security of Connections

• Launch Rail and Pad

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Launch Procedures

• Configuration and Arming • Place Rocket on Launch Pad • Non-Level Two Members Retreat • Arm for Ignition • Disarm Safeties • Remaining Members Retreat

• All Clear and Launch • Receive All Clear from RSO • Initiate Rocket Ignition • Watch Flight from Safe Viewing Area

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Launch Procedures

• Retrieval • Receive Clearance for Retrieval

• Safety Office Retrieves Launch Vehicle

• Disarm Unfired Charges

• Disassembly & Inspection • Disassemble Launch Vehicle

• Record Altimeter Data

• Recover Fragile Payload

• Inspect Subsections for Cracking/Fatigue

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Troubleshooting

• Cracking in Body Tube/Subsection • Replace with Spare Component • Evaluate Severity of Structural Flaw • Load Bearing Determination

• Non-Load Bearing: Epoxy • Load Bearing: Postpone Launch and Refabricate

• Insecure Connection • Replace with Spare Component • Oversized

• Sanding Operations • Undersized

• Increase Diameter with Layers of Tape

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Troubleshooting

• Malfunctioning Electronics • Inspect Wiring for Disconnection • Test Battery • Inspect Wiring Switch • Examine Terminals • Replace Unresponsive Component

• Launch Rail/Pad Connection Insecurity • Inspect Launch Pad for Debris • Inspect Launch Rail for Bowing • Tighten Threaded Bolts • Drill New Holes for Threaded Bolts

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Launch Vehicle Requirement Verification (NASA) Handbook

Number Summarized Requirement Description of Verification Plan Status & Location

1.1

The vehicle shall deliver the science

or engineering payload to an

apogee altitude of 5,280 feet above

ground level (AGL).

The rocket team will utilize

OpenRocket, RockSim, CFD, & test

flight data to achieve an accurate

prediction of altitude.

Full scale test completed with

apogee of 5,291 feet. See “Full

Scale Flight” for more detail.

1.7

The launch vehicle shall be capable

of being prepared for flight at the

launch site within 4 hours.

The team will conduct multiple tests

on full-scale test day and measure

re-launch times.

The team was able to prepare the

rocket in 32 minutes on February

18th. See “Full Scale Flight” for

more detail on multiple launches

that day.

2.1

Vehicle must deploy a drogue

parachute at apogee, followed by a

main parachute at a much lower

altitude.

Dual-deployment altimeters are

programmed to fire ejection charges

at apogee and at 750 feet.

Full-scale test flights resulted in

successful recovery events. See

“Full Scale Flight” & “Recovery”

for more.

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Team Requirement Verification

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Number Requirement Description of Verification

Method Status & Location

1

All reports shall be compiled at

least three days prior to NASA due

dates.

Reports shall be completed,

according to team schedule, prior to

NASA due dates to allow for

revision time and mitigate risk of

late submissions.

The team has completed all

reports on time.

2

Each member of the team shall

have a working knowledge of each

subsystem.

At each team meeting, every sub-

section lead will review the status of

their section with the entire team.

The team leader will confirm that

the information presented is

sufficient.

This has been maintained. It was

recently demonstrated at the full-

scale launch where team members

had to work on each other’s

sections.

3 Safety shall be made the team’s

first priority.

The safety officer will periodically

ask team members what the most

important aspect of the project is.

Safety officer has asked 17 team

members what the most

important part of the project is

and has had 15 “safety” answers.

The two outliers have been

reminded of safety.

Payload Requirement Verification

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Requirement Complete?

Reduce acceleration and force felt by objects in Cylinder 1 of payload by 50%

Unknown-faulty accelerometer

Successfully protect sample fragile materials during testing and full-scale launches.

Completed successfully

Thank you for your time!

Questions?

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Documents

Flight Readiness Review - University of Evansville · Full Scale Flight Narrative Simulation Launch Day Conditions Quick Links Ballast (lb) Simulated Apogee (ft) Actual Apogee (ft)