colorado state university paul scholz, tyler faucett, abby wilbourn, michael somers june 14 2010 1

Colorado State University Paul Scholz, Tyler Faucett, Abby Wilbourn, Michael Somers June 14 2010 1

Mission Overview Objective: to study alternative energy collection at different altitudes Find the ideal altitude for alternative (wind & solar) energy collection. Is high altitude energy collection worthwhile? Can the added cost of high altitude energy collection be made up for with increases in efficiency? 2

Current Products MARS Maggen Air Rotor System 3

CoolEarth Solar Balloon MARS turbine 4

How we can help Our test could provide useful data to someone wishing to put up a similar system on Earth or Mars An airborne solar/wind power farm could be very useful for remote area power generation Our test vehicle will provide data to give an altitude of maximum power generation. 5

Mission Requirements 6 REQUIREMENTMETH ODSTATUS Payload mass must be 1.5 kg or lessDesign and use of lightweight materials Payload must accommodate flight string per the users guide Design and test Payload must pass all structural tests in users guide Design and test Payload must successfully complete all functional and environmental tests Design and test Payload must have the capability to complete all mission objectives Design and test Payload must cost under $1000Budget carefully

Concept of Operations Just before launch power to the heaters and microcontroller will be turned on via switches on the top of the payload The microcontroller will run its program which includes taking input from 5 different sources and transmit the data serially back to the SD card at a rate which we will specify for each sensor After the program has run for 150 minutes, the program will end so that we do not write over our flight information with data collected on the ground 7

Subsystems Structural Thermal Data Storage Processing Electrical Sensing 8

Subsystem Structural Must have cylindrical shape Allows for even and constant sun exposure to solar faces Must have center core flight string pass through Pass through design must comply with all DemoSAT-B regulations Pressure differences inside and outside the payload must not exceed 10 psid 9

Subsystem - Thermal The internals of the payload must remain above 0C to prevent failures of electrical components The internal electrical components must be placed as close to the center of the payload as possible Internal flexible heaters will be installed to maintain required internal temps. Flexible heaters allow for easy placement near critical components (battery) Temp. Distribution Flux 10

Subsystem - Data Processing All sensor data shall be processed on a PIC 16F884 microcontroller Storage The PIC shall send data from the sensors to the data storage unit every 5 seconds The data storage device shall be removable and portable and must allow for computer interface 11

Subsystem - Electrical All electrical components must be powered by a 5V source The power supply must be able to produce 4.8V to 6V for at least 2 hours Switches for electrical components must be mounted on the external of the payload 12

Subsystem Sensing Wind Speed Sensing Anemometer must be at least 2in from the flight cord At least 2 axis of acceleration must be sensed to accurately measure wind speed Altitude Sensing Payload must contain at least 1 pressure sensor and 1 temperature sensor Pressure and Temp must be measured externally for accurate data Solar Panels Solar panels must cover at least 90% of the rounded faces of the payload All external sensors must be able to operate at temperatures ranging from -80C to 30C 13

Subsystems Block Diagram 14

Schematics/Drawings/Analysis 15

100mph winds at -80C 5W internal heat generation Steady state. 20

100mph winds at -80C 5W internal heat generation Steady state. 21

Commands and Sensors Sample Rate Sample Duration # of samples Bytes/ Sample (estimated) Min Required Memory For data storage Available Memory 1 sample every 5 seconds 2 hours 1440 (samples/ sensor) * 6(sensors) = 8640 samples 4 bytes34560 bytes2Gb SD (less due to formatting, etc.) Data transferred serially from PIC microcontroller to SD card mounted in SD card reader. 22

Sensor Specifications SensorOperational Voltage Operational Temperature Measurement Range Notes Temperature3.0 to 5.5V-55C to +125C Converts Temperature to 12-bit Digital Word in 750 ms Pressure5.0V0C to 85C0 psi to 1 psi through 0 psi to 100 psi Response time of 8 ms Accelerometer (2-axis) 2.4V to 5.25V-20C to 70C+/- 18g----- Cup Anemometer ----- 3 mph to 125+ mph 2.5 mph per Hz (1 Hz=1 pulse/sec) Solar Panels (3) ----- Voltage: 7.2 V Watts: 1.44 W Amperage: 200 mA 24

Accelerometer Math 25 X and Y out were generated randomly Samples were taken every second for this example

Test Plans Testing Types Structural Test Whip test Drop test Stair pitch test Environmental Test Cooler Test Functional Tests Bench Test 26

Structural Tests Test Structure Made in the same fashion as actual structure with minor differences Heavier outer shell with no carbon fiber around the foam Thicker (2x) mounting plate Ballast taped to mounting plate on inside Accelerometer bracket attached Aluminum square screwed to top to simulate the anemometer. Total weight was 3.25 lbs 27

Test Structure Photos 28 Assembled test structure Pieces of ballast usedRemovable Frame

Whip Test Performed 5 whip tests and took video of all of them. Payload was spun overhead as fast as possible After being at speed for several revolutions the experimenter pulled in on the string as hard as possible to simulate a high g-load. The length of rope from the hand of the experimenter to the payload cg was 80 inches From the video the calculated angular velocity was 60 RPM The calculated g load at these conditions was 8.2g with the peak during the pull being higher 29

Potenial Damage/Assessment Top plate could have been bent Epoxy interface between the tube and fitting could fail Acrylic posts imbedded in the foam could pull out or break No damage was observed during this test 30

Whip Test Video 31

Stair Pitch Test Structure was kicked down a flight of 13 concrete steps Step profile was 7.25 inches tall and 10.5 inches long 32

Potential Damage/ Assessment CF tube could break Foam could fracture Acrylic posts breaking or pulling out Top plate bending One Acrylic post was broken during the tumble at the base of the nut All other parts were unharmed Possible fix would be to shorten the posts to be only as tall as the nuts to lessen the moment on impact 33

Drop Test Structure was thrown off a balcony from a height of 22.63 ft. above the concrete ground It landed almost sideways but angled enough that the top plate took the initial impact 34

Potential Damage/ Assessment Broken CF tube Acrylic posts breaking or pulling out Foam breakage Top plate bending The top plate was bent from impact The foam fractured and broke from impact The foam layers separated near the region of impact The fix for the foam is that it will be encased in a carbon fiber outer shell 35

Structural Test Summary No repairs were made during testing Weak points were discovered to be the acrylic posts and the top aluminum plate Of the five pieces of ballast originally taped to the mounting plate before the tests 3 were still attached The plate may have bent less from the drop test if the third post had still been there From the tests we are confident that the electronics on our payload will survive the extreme conditions they may encounter and our data will be recoverable 36

Secondary Whip Test This test was added after the other tests had been completed and analyzed In this version of the whip test, we dropped the payload attached to a 10 foot rope The sudden stop the payload experienced as the rope came to its full length was a better way to impart a sudden directional change in order to determine if the posts would hold, and if the internal electronics would stay secure All other tests had been performed previously, and the damage was repaired 37

Potential Damage/Assessment The post that previously broke and was re-glued broke again Minor foam fractures around the posts No internal ballast pieces separated from the mounting plate Overall, there was no significant additional damage to the structure. We are still confident that the top plate will remain secure, as well as the internal electronics Vibration testing may be analyzed when all electronics are in place to verify that our data will be retrievable 38

Secondary Whip Test Video 39

Environmental Tests Cooler Test Must purchase Dry Ice and Cooler Potential Point of Failure: Payload: Insulation design may be flawed and low internal temps may cause freezing/condensation on electrical components. Adjustments may need to be made to heater placement and insulation 40

Solar Panel Cold Test The solar panel output will be tested for variations in temperature The panel, a 90 W light source above the panel, and a thermocouple will be placed inside a refrigerator originally at room temperature The refrigerator will then be turned on to its highest setting The solar panel output and temperature will be recorded at a constant temperature interval of 2 degrees Celsius 41

Setup 42

Results The starting temperature was 22 C Final temperature was -18 C Voltage readings were taken with a multimeter every two degrees The voltage readings combined with known resistance values yielded current and power Dry ice was added to the refrigerator to reach the lowest temperature 43

Temperature Relationships 44

Functional Test Bench Test Potential Points of Failure: Overheating of internal electrical components No data transmission to SD Card No data transmission from sensors Wiring failure 45

Parts List 46

Schedule 47

Mass BudgetMonetary Budget 49

Questions? 50

colorado state university paul scholz, tyler faucett, abby wilbourn, michael somers june 14 2010 1

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