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This report outlines the mission objectives of measuring Earth's magnetic field, analyzing flight dynamics of the rocket, capturing atmospheric biological samples, and studying UV intensity and DNA damage as a function of altitude. Current challenges include incomplete payload integration, malfunctioning sensors, and data transmission issues. New tests have been conducted on system performance and mechanical design stability. The report also details the structure, weight properties, and functionality of subsystems, including filters and power management critical for mission success.
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Full Mission Simulation Report Temple University Fred Avery, Gene Council, Ny’JaaBobo, Salvatore Giorgi, Jay Shukla 4/21/12
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 Overview Current 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 data
Mission Overview - Testing Tests Previously Completed • Filtration System Temperature Tests • Filtration System Pressure Tests • Data Collection • Power • Spin • Plate Stress/Strain Simulations
Mission Overview - Testing 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 • 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 • 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 • 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 - Structure Standoffs • Size: 5/16” Hex Size, 8-32 Screw Size, 2” length • Same type and size as Drexel’s though ours are made of steel 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 - Structure Center of Gravity • X = 1.00 in • Y = 0.91 in • Z = 0.94 in Current Weight • 6.04 lbs • Approximately 3 lbs per plate • Steel blocks (~1 in3) will be used to add weight (~1 lb each)
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
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
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 5.14×108Pa • Expected Stress will not exceed Standoff Strength • Material is able to withstand the force expectancy
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)
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
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 sun
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 spinning
Power (EPS) • 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
Action Item Summary Week 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
Action Item Summary Week 3 • Have entire canister constructed • Fully integrated with Drexel • Drop down tubing integration completed sorted Week 4 • Complete all Launch Readiness tests
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