Full Mission Simulation Report

Temple UniversityFred Avery, Gene Council, Ny’Jaa Bobo,

Salvatore Giorgi, Jay Shukla4/21/12

Mission Overview• Measure the earth’s magnetic

field as a function of altitude • Measure flight dynamics of

the rocket• Capture biological samples in

the atmosphere• Identify types and

concentration of samples as function of altitude

• Measure UV intensity as function of altitude

• Identify UV damaged DNA in samples

Figure: A UV radiation induced thymine-thymine cyclobutane dimer (right) is the type of DNA damage which is undone by photolyase.

Mission OverviewCurrent Problems• Fully integrated payload is still not complete– Not able to get plates cut– Standoffs ordered but not delivered

• Magnetometer is still not functioning with microprocessor– Looked into other models, but all cheap sensors require I2C

protocol, which seems to be where the problem is• Decoding the spectrometer data

– Spectrometer uses data compression when transmitting data– Currently working on method to decode the compression– In the end, this is not needed as we have enough memory to

store uncompressed data3

Mission Overview - Testing

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Tests Previously Completed• Filtration System Temperature Tests• Filtration System Pressure Tests• Data Collection• Power• Spin• Plate Stress/Strain Simulations

Mission Overview - Testing

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New Tests Completed• Additional Power Tests• Additional Data Collection Tests• Standoff Simulations– Deflection– Stress– Loading

• Spectrometer Integration Time• New Center of Gravity Simulations• System Activation

Subsystem Overview - Mechanical

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• No changes have been made to this subsystem since last report

• Filter system consists of four filter holders, one manifold and four servo motors

• Servos are mounted to top of manifold and control the air flow to the filter holders.

Subsystem Overview - Electrical

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• No official changes have been made to this subsystem since last report

• Electrical system consists of one microprocessor, two accelerometers, magnetometer, gyroscope, and a spectrometer

• The magnetometer will be mounted on the top plate while the remaining item will be located on the bottom plate

Subsystem Overview - Power

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• No changes have been made to this subsystem since last report

• A total of 3 batteries will be used to power the system

• All sensors will be powered by microprocessors

• System activation will be done with a RBF pin

Mechanical - StructureStandoffs– Size: 5/16” Hex Size, 8-32 Screw Size, 2” length– Same type and size as Drexel’s though ours are

made of steel

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Plate Problems

–Laser Cutter will now be used to machine plates–Makrolon (Polycarbonate) cannot be laser cut–Acrylic will now be used in co ordinance with Drexel’s payload

Mechanical - StructureCenter of Gravity• X = 1.00 in• Y = 0.91 in• Z = 0.94 inCurrent Weight• 6.04 lbs• Approximately 3 lbs per plate• Steel blocks (~1 in3) will be used to add

weight (~1 lb each)10

Mechanical – Parts List

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Part Number Needed for Flight

Number In Possesion

Plates 2 4

Standoffs 5 10

Filter Holders 4 8

Tubing (Filter System) ~1’ 25’

Tubing (Drop Down) 8’ 20’

Servo Motors 4 8

Manifolds 1 4

Leur Lock to 1/4” barbed 1 25

Leur Lock to 1/8” barbed 8 25

Mechanical – Parts List

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Part Number Needed for Flight Number In Possesion

Barbed Y fittings 3 10

NPT Femal to 1/8” bardbed 4 25

Filter Holders 4 8

Voltage Regulator 1 5

Servo Microprocessor 1 2

Electronics Microprocessor 1 2

Accelerometer 1 2

Magnetometer 1 2

Spectrometer / Fiber Optics Cable / Cosine Corrector

1 1

SD Card Reader / SD Card 1 2

Mechanical - Standoffs• Deflection Simulation

– As a worst case scenario, wind gusts may affect structure and standoffs could be affected

– The maximum force expectancy during flight is about 3380 N

– Standoffs will deform about 0.5 mm (~0.02 in) if at all

– Color represents severity and value of deformation (Red being maximum, blue being minimum)

– The most deformation will occur in the center of standoff due to the fixed ends

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Mechanical - Standoffs• Shearing Simulation

– A force of 3380 N in each axis may affect the payload structure

– This force will not highly affect the standoffs being used

– Only a moderate amount of stress will result from the force expected and will not exceed material strength

– The fixed ends cause standoffs to deflect

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Mechanical - Standoffs• Total mass of canister is 9.07 kg• Max loading expected during

flight is 38 g• Total force acting on standoff is

9.07 kg*38*9.81m/s2 = 3380 N• Stress expectancy during flight

is 74,700 Pa • Standoff strength is 5.14×108 Pa• Expected Stress will not exceed

Standoff Strength• Material is able to withstand the

force expectancy

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Mechanical – Filter System• Fully constructed• Processor is programmed with all

timing information• Batteries proven to power system• Fully functional during previous

temperature tests• Plan to further minimize leak with high

vacuum grease• Grease will not contaminate filters• Need to wait until end of semester to

get access to vacuum pump (first week of May)

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Electrical – System Activation

• Previously changed from g-switch to timer activation• We use a delay command• Designed software so that we change constant

parameter minute to change the activation time• This will give us more flexibility in the event our

activation time changes before launch• delay command in arduino delays the program by a

specified time in milliseconds• Example:

– delay(minute*60*1000)• Parameter is unsigned integer, which must be less

than 232

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Electrical - Spectrometer

• Higher integration time may saturate data• Low integration time will not give relevant data • Canister spins at 5.6 rev/sec and thus field of view passes over

the sun at least 5 times per sec• Graph above shows spectrum with various integration times on

sunny day with fiber optics cable pointed directly at sun18

Electrical - Spectrometer

• Above graph shows spectrum with varying on a very overcast day with fiber optics cable pointed away from sun

• Will do further testing in Chemistry department to determine integration time needed– Tests will using laser pulses to simulate optical port facing

sun while spinning19

Power (EPS)

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Battery Initial Voltage (V) Final Voltage (V)

Electronics Microprocessor

9.07 8.65

Servo Microprocessor 9.01 8.90

Servos 9.02 7.22

• Above table shows voltage values for 30 minute flight simulation

• Batteries were able to power everything, as expected

Software• Data collected for 30 minute flight is

1.4 MB with spectrometer included• Problems– Software still not working for

magnetometer and pic32 board– Software not able to run through

multiple spectrometer integration times while sampling other sensors

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Action Item SummaryWeek 1• Cut plates (or at minimum, schedule time with

Drexel for cutting)• Purchase drop down tubing and fittings• Detailed full canister integration procedure

Week 2• Full canister center of gravity simulations• Finalize spectrometer integration time• Test vacuum grease• Finalize all sensor problems

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Action Item SummaryWeek 3• Have entire canister constructed

– Fully integrated with Drexel– Drop down tubing integration completed sorted

Week 4• Complete all Launch Readiness tests

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Conclusions• Besides being physically connected we

feel as though our system is very close to being launch ready

• Focus will be on working with other teams to get the full canister ready for launch

• With end of semester next week, all team members will be able to give this project their full attention

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