STUDENT LAUNCH INITIATIVE 2010 – 2011 AIAA OC SECTION FRR PRESENTATION APRIL 4, 2011 \

$: STUDENT LAUNCH INITIATIVE 2010 – 2011 AIAA OC SECTION FRR PRESENTATION APRIL 4, 2011 \$
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STUDENT LAUNCH INITIATIVE2010 – 2011

AIAA OC SECTION

FRR PRESENTATION

APRIL 4, 2011

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Student Launch InitiativeAIAA OC Section

Agenda Team Introduction Finalized Vehicle Motor type and selection Rocket flight stability Parachute and descent rates Test plans and procedures

• Black Powder test• Dual Deployment• Full scale lunch

Lessons learned – Vehicle Payload Payload integration Lessons learned – Payload Educational Outreach Questions

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Modified Since Original Posting Almost Everything

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Finalized Vehicle – Black Brant

Parameter DetailsLength/Diameter 87.5 inchesDiameter 4 inchesMaterial (body and fins) FiberglassShock Cord 1” tubular Nylon 15 feetMotor Diameter / Retention 54mm Aero Pack Quick-Change

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Forward Section – Black Brant

Parameter DetailsNose Cone 20” Long holding triangular piece of 1/8” plywood with GPS

mountedForward Bulkhead 3 ply x 3/32” = 9/32” fiberglass 4” back from front end of body

tube with “U” bolt for shock cord attachment via 1200 lb test quick link

Forward Cavity 17” x 4” (16” unobstructed) containing 72” main parachute, 1” tubular nylon shock cord, Kevlar Protectors for parachute and shock cord, and black powder charges

Ejection Charge 2.17 grams of black powder gives 20 psi and 250 lbs of force to shear 3 2” nylon shear pins and eject the main parachute

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Avionics Bay – Black Brant

Parameter DetailsBay Two 8” couplers (16” total) with 8” body tube centered and epoxied in

placeBulkheads 3 ply x 3/32” = 9/32” fiberglass (one is smaller diameter to align with

inside of coupler with two terminal blocks for e-matches on each end and one 5250 lb test closed stainless marine eyebolt

Threaded Rod Two ¼” threaded rods run the entire length of each side of the bay and are secured on the outside of the bulkheads with nuts / wing nuts

Electronics All electronics are mounted on two 1/8” plywood sleds approx 4” x 16:

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Rear Section – Black Brant

Parameter DetailsCentering Rings Two 2 ply x 3/32” = 6/32” fiberglass 4” diameter centering rings

hold the 54mm fiberglass engine tube in the 4” fiberglass body tube – the forward ring has a “U” bolt for shock cord attachment via quick link. One additional centering ring is in the tail cone

Rear Cavity 17” x 4” (8” usable with the engine in place) containing 24” drogue parachute, 1” tubular nylon shock cord, Kevlar Protectors for parachute and shock cord, and black powder charges

Ejection Charge 1.74 grams of black powder gives 15 psi and 200 lbs of force to shear 3 2” nylon shear pins and eject the drogue parachute

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Finalized Vehicle – Black BrantParameter DetailsCenter of Pressure / Center of Gravity

62.02 inches / 52.48 inches (from tip of nose cone)

Stability Margin 2.36Launch Rail type / Length 1 inch / 6 feetRail Exit Velocity 55 ft/secWeight liftoff/descent 17.75 lbs / 13.85 lbsPreferred motor (K635) Average Thrust

635 Newtons (142.75 lbs)

Thrust to weight ratio 8.04:1Maximum Ascent Velocity 686.10 ft/sec (.60 mach)Maximum Acceleration 434.94 ft/s/sPeak Altitude 5266 ft

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Velocity Vs Time Graph

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Static Margin Diagram

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Construction Details

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Process Details

All fiberglass surfaces are fully scuffed and scratched before they are epoxied.

After scuffing the surfaces are fully cleaned with Isopropyl alcohol to remove dust and any oils or other contamination. All parts are epoxied together using West Systems Epoxy.

Since the bulkheads were only 3/32” thick, three bulkheads were glued together for added strength

Fillets are applied to all joints for added strength

Construction Details cont’d

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Process DetailsThe Avionics bay uses closed eye bolts since the stresses at ejection can open eyes that are not continuous or welded shut“U” Bolts are used on the centering rings and top bulkhead also for strength

To assure things fit properly we dry-fit parts together and inserted an engine casing – centering ring “U” bolt, quick link, shock cord.To assure fins aligned properly we used a fin jig

Fiberglass tape was applied to the body tube – fin joint to help reinforce that areaWhenever possible, ferrules were crimped on to the end of wires to keep the strands together and make certain there is good connection

Motor Selection

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Motor Properties Preferred Selection Alternate Selection

Manufacturer Cesaroni 5 grain Cesaroni 5 grain

Motor Type K635 Red Lightning K490 Green

Max, Average Thrust(Newtons)

656 Newtons 490 Newtons

Total Impulse 1749.5 Newton-seconds 1978 Newton-secondsMass of Motor Before / After Burn

4.38/1.45 lbs 4.08/1.44 lbs

Max Altitude 5266 ft 5208 ftMax Velocity 640 ft/sec 686 ft/secMax Acceleration 434 ft/s/s 434 ft/s/sTime to Apogee 18.13 17.66

Cesaroni K635 Red Lightning(Preferred)

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Brandname Pro54 1994K635-17A Manufacturer Cesaroni Technology

Man. Designation 1994K635-17A CAR Designation

1994-K635-17A

Test Date 7/6/2003

Single-Use/Reload/Hybrid Reloadable Motor Dimensions mm

54.00 x 488.00 mm (2.13 x 19.21 in)

Loaded Weight 1989.90 g (69.65 oz) Total Impulse 1749.50 Ns (393.64 lb.s)

Propellant Weight 1281.00 g (44.84 oz) Maximum Thrust

728.70 N (163.96 lb)

Burnout Weight 658.40 g (23.04 oz) Avg Thrust 656.00 N (147.60 lb)

Delays Tested 17 - 7 secs ISP 139.30 s

Samples per second 1000 Burntime 2.66 s

Notes Red Lightning™

Cesaroni K490 Green(alternate)

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Motor Data

Brandname Pro54 1990K490-16A Manufacturer Cesaroni Technology

Man. Designation 1990K490-16A CAR Designation 1990-K490-16A

Test Date 1/7/2010Single-Use/Reload/Hybrid

Reloadable Motor Dimensions mm

54.00 x 488.00 mm (2.13 x 19.21 in)

Loaded Weight 1854.1 g Total Impulse 1978.4 Ns (44.8 lb-s)

Propellant Weight 1155.4 g Maximum Thrust 590.9 N (132.8 lb)

Burnout Weight 652.9 g Avg Thrust 485.5 N (109.2 lb)Delays Tested 16 - 6 secs ISP 174.16 sSamples per second 1000 Burntime 4.08 s

Notes Green3™

Parachute Size & Descent Rates Rocket mass = 221.65 oz Drogue chute diameter = 24 in. Main chute diameter = 72 in. Calculated projected velocity

for each chute with online calculator and by hand

v2 = 2FD / (ρ)(CD)(A)• CD = 1.00• FD = mg = (6.285 kg)(9.8 m/s2)

Hand: vdrogue = 60.99 ft/s Online: vdrogue = 68.57 ft/s Hand: vmain = 17.43 ft/s Online: vmain = 19.59 ft/s Required: Drogue 50-100 ft/s Main: 17-22 ft/s

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GPS TRACKING

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Transmitter in Vehicle

• Big Red Bee Beeline GPS• RF: 17mW on 433.920 MHz• Battery and life: 750mAh 10 Hrs• Size: 1.25” x 3” 2 ounces

Ground Station

• Receiver: Yaesu VX-6R• TNC: Byonics Tiny Track 4• GPS: Garmin eTrex Vista

Beeline receives GPS position• Encodes as AX.25 packet data• Sends as 1200 baud audio on 433.92 MHz

VX-6R receives at 433.92 MHz and extracts audio TinyTrack 4 converts audio to digital NMEA location data Garmin displays the digital location data on human screen

Payload G-Wiz Partners HCX flight

computer - measures acceleration of the rocket

Toshiba hard drive – test subject; we will run a Linux script on the hard drive over and over again; the time the hard drive takes to run the script each time is measured

Simple net computer/Linux computer – the mini computer that will execute the Linux script on the hard drive; it will be initialized automatically; the flight data will be recorded on a flash drive inserted into this computer

Power converter – Keeps a steady flow of power to the payload components

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Payload Details

Program Source Code#!/bin/shPATH=/binwhile truedo date >>/var/ftp/LEXAR/log.txt time dd if=/dev/zero of=/dev/sda2 bs=65536

count=32 skip=64>>/var/ftp/LEXAR/log.txt 2>&1

time sync >>/var/ftp/LEXAR/log.txt 2>&1 time dd if=/dev/zero of=/dev/sda2 bs=65536

count=32 skip=128>>/var/ftp/LEXAR/log.txt 2>&1

time sync >>/var/ftp/LEXAR/log.txt 2>&1 tail -n 10 /var/ftp/LEXAR/log.txtdone

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Program Output (Log File)Fri Feb 11 22:36:49 UTC 20118+0 records in8+0 records outreal 0m 0.10suser0m 0.00ssys 0m 0.06sFri Feb 11 22:36:49 UTC 20118+0 records in8+0 records outreal 0m 0.20suser0m 0.00ssys 0m 0.06sFri Feb 11 22:36:49 UTC 20118+0 records in8+0 records outreal 0m 0.16suser0m 0.01ssys 0m 0.05s

On power up, the Linux computer starts executing a shell script that repeatedly writes and reads 32 K Bytes of zeros to the hard drive, logging the time this takes to a flash thumb drive

Payload Integration

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•The payload will be screwed onto the assembly•Batteries are held by a combination of battery holders and zip ties•Wires are crimped, except for those going to the battery holders, which are tinned•Power to the components are controlled by key switches

Test Flight #1 Payload Results

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Observed Results• The script started properly and began to measure and record times• The script continued to run properly, but shortly after launch the file

system on the hard drive became corrupted so accesses stopped and no meaningful data was recorded

• The hard drive was not damaged and could still be used (with reformatting)

Changes before next flight• The file system will no longer be used – we access the raw sectors on

the disk – yielding the following advantages. There is no file system code There is no risk of erroring out due to a corrupted file system We have more control over the seeking of the hard drive Code runs much faster since without the file system

Recovery Electronics

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Flight Computer #2 G-Wiz Partners HCX 56G 1.10” x 5.50” 45 grams Accelerometer based altitude Pyro output at Apogee Pyro output at 900 ft altitude 9VDC at 65ma for 3 hour battery life Separate CPU and Pyro batteries Two Safety interlock switch on body

tube (1-CPU and 1-Pyro)

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Flight Computer #1 PerfectFlite MAWD .90” x 3.00” 20 grams Barometric pressure based altitude Pyro output at Apogee Pyro output at 900 ft altitude 9VDC at 8ma for 28 hour battery life One battery for both CPU and Pyro Safety interlock switch on avionics

bay

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Recovery - Dual Deployment Electronics: MAWD Perfect Flight, HCX G-Wiz Partners The electronics will “back” one another up in case one

pyro (either drogue or main) does not fire. Drogue Parachute will be deployed at apogee Main Parachute will be deployed at 900ft The electronics have been tested several tests have

been done:• Christmas tree light test • Vacuum Chamber test• Second flight in the scale rocket (MAWD Only)• Third Flight in scale model (MAWD Only)• First Flight in full scale model (MAWD and HCX)

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Previous Recovery Electronics Tests

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Electronics Test StatusChristmas Tree Lights substituted for e-match – control from softwarePerfectFlite MAWD No software control N/AG-Wiz Partners HCX Manual control from software OKG-Wiz Partners HCX Test flight from stored altimeter data OKChristmas Tree Lights substituted for e-match – control from vacuum in chamberPerfectFlite MAWD 2.6” avionics in homemade chamber (pickle jar) OKPerfectFlite MAWD 4” avionics in homemade chamber (large Tupperware) OKG-Wiz Partners HCX 2.6” avionics in homemade chamber (pickle jar) OKG-Wiz Partners HCX 4” avionics in homemade chamber (large Tupperware) OK

Flight Test StatusScale #1 (1938 ft) Motor ejection – MAWD as altimeter only OKScale #2 (1740 ft) Dual Deployment – MAWD only PARTIAL – both chutes

deployed togetherScale #3 (1581 ft) Dual deployment – MAWD only OK

Black Powder ChargeCalculating the black powder charges is a two step process Pressure needed to shear pins (#2 screws - 3x35lbs each) and eject the parachute. We

will use 200lbs (drogue) and 250 lbs (main) to shear pins, overcome friction and eject.Surface Area = π * r 2 = 3.14 * 22 = 12.56 in2 For 200 lbs / 12.56 in2 = 15.9 PSI

250 lbs / 12.56 in2 = 19.9 PSI

Amount of black powder to reach that pressure Grams of Black Powder = C * D2 * L

Where: D = Diameter of the airframe in inches L = Length of the airframe in inches C = 0.006 for 15psi and 0.008 for 20 psi.For a 4” diameter airframe of 17” long, we require

200 lbs (16 psi) = .0064 * 42in * 17in = 1.74 grams250 lbs (20 psi) = .008 * 42in * 17in = 2.17 grams

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Black Powder Charge Test The table below shows the testing our team has done with black

powder charges

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Full Scale Amount Successful?Sustainer without parachute 1.74 Yes

Sustainer with parachute 1.74 Yes

Main without Parachute 1.43 Yes

Main with parachute 1.43 No

Main with parachute 1.74 No

Main with parachute (packed tighter, ejection charge relocated)

2.00 Yes

Other Previous Testing

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Test Results Required Status

Battery Life MAWD 36+ hrs 2.5 hrs OK HCX (CPU/PYRO) 2.5/6.7+ hrs 2.5 hrs OK GPS 18.7+ 2.5 hrs OK Scientific Payload 3.7+ 2.5 hrs OKGPS Range 3 miles 1 mile OKScale Rocket (3rd flight)

Good Flight Good Flight OK

Dual Deployment on Scale Rocket

OK OK OK

1st Full Scale Flight Analysis

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• First Flight• Cesaroni K400 (Total thrust: 1597 – Burn 3.2s) • Wind was very heavy (15 MPH)• Vehicle was stable although it did weathercock• All ejection charges fired at the proper times• Drogue deployed just after apogee as programmed• Main ejection charge did not fully deploy the parachute• Reached 3339 ft at apogee• Partiall successful flight (see curve from MAWD)

Corrective Actions

After the first flight we did several additional ground tests to deploy the main until it fully and easily deployed:• Increase the black powder charge to 2.5 grams• Move the black powder charge so it pushes the parachute out from behind• The parachute needs to be rolled much tighter• The shroud lines need to be wrapped around the outside of the parachute to hold

its tight packing• The attachment point of the parachute is now right at the avionics bay instead of

1 foot away along the shock cord• The Nomex shield protecting the shock cord has been replaced by a sleeve to

minimize obstructions• The Nomex shield protecting the parachute needs to be packed around it like a

burrito.29


2nd Full Scale Flight Analysis

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• Second Flight• Cesaroni K500 (Total thrust 1596N – Burn: 4s)• Wind was very light/moderate (5-8 MPH)• Vehicle was stable and flew straight• All ejection charges fired at the proper times• Drogue deployed just after apogee as programmed• Main deployed at 900 feet as programmed• Reached 4059 feet• Successful flight (see curve from MAWD)

Second Flight Full Scale Launch

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Lessons Learned from Scale Model Test Flight

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Lesson Original Fault Was it successfulSimplify wiring, color code everything, allow extra space, use ferrules to keep the wires together

The scale model avionics was too crowded, hard to trace. Some wires did not make good contact in terminal blocks

Yes it was successful but we learned we have to be careful so we don’t stress the key switches

Gel coat must be ground down to fiberglass underneath before applying epoxy

The scale rocket was wobbly near apogee – inspection showed the lower 1/3 of the fins were not attached

Yes it was successful because a subsequent flight after fix was stable again

Always use shear pins to avoid drag or impulse separation

We did not use shear pins and we deployed the main when the drogue deployed

Yes because a subsequent flight deployed drogue and main separately as designed

Stick with your plan and do not let on-site “mentors” sway you

We listened to an on-site mentor when he said we did not need shear pins – rocket was too small

Yes – with all of our research, engineering, and design we did know better than he did

Recovery Lessons Learned from Full Sized Vehicle Test Flight

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Lesson Original Fault Was it successfulAlways test in conditions closest to the final conditions

We tested our black powder charge without the parachute in place to verify the airframe would separate. We should have had he packed parachute in place to assure deployment

Yes – in subsequent ground testssuccessful on flight #2

The parachute must be very tightly packed, with shroud lines wrapped around the outside

The main parachute did not deploy fully on our first test flight


Charges should be place so that the parachute is pushed out by the charge

The main parachute did not deploy fully on our first test flight


Payload Lessons Learned from Full Sized Vehicle Test Flight

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Lesson Original Fault Was it successfulThe file system can become corrupt – when testing the hard drive access sectors directory

The file system became corrupt during launch, but the hard drive was OK – we are testing the hard drive

Successful on 2nd launch

The battery holders need extra support and retention for the battery. Tie wraps need to be extra tight

Two plastic battery holders broke during launch – one battery was disconnected. Tie wraps were not tight enough

Successful on 2nd launch

Results are more meaningful when accuracy is greater by flushing caches allowing quicker execution

Results were hard to determine

Yes during ground tests

Website AIAAOCRocketry.org SLI 2010-2011

• Documents• Calendar• Photos/Videos• Manuals• MSDS

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Educational Outreach Cloverdale 4-H club Girl Scouts workshop Presentations to Sunny Hills High School Science classes to

get involved Articles published/ will be published in the Orange County

Register, The Foothill Sentry, and the Sunny Hills High School Accolade

We will have a booth at Youth Expo, April 9th to April 11th, we will reach a few hundred kids.

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Thank you for letting us be part of SLI

Questions?

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STUDENT LAUNCH INITIATIVE 2010 – 2011 AIAA OC SECTION FRR PRESENTATION APRIL 4, 2011 \

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Transcript of STUDENT LAUNCH INITIATIVE 2010 – 2011 AIAA OC SECTION FRR PRESENTATION APRIL 4, 2011 \