1. Follow up Design Review The University of Northern Colorado GoGreenSAT Jessica Gage, Max Woods, Brent Hill, Ryan Marshall, Zach Sears Mar. 27 2009

2. Index SectionSlide Number Mission Overview3 Mission Requirements4 Fundimental Block Diagram5 Concept of Operations6 Structual Drawings7 8 Structure**9 Schematic*10 Parts List*11 Subsystem Overview*12 Subsystems-Peltier Cooler**13 Subsystems-Pendulum**14 Test Plans15 Cold Test Results**16 Cold Test Results**17 Cold Test Results**18 Management19 Conclusion20 Appendix A-Calculations: Impact Test**21 Appendix B-Weight Breakdown**22 Appendix C-Box Dimensions**23 *Change from original CDR, **New since original CDR

3. Mission Overview  The goal of GoGreen SAT is to observe the most effective materials and conditions in which a payload can generate energy to be used and stored.  GoGreen SAT will determine the maximum energy output of different onboard systems throughout the flight.  The three energy systems are:  Pendulum: Capturing the swinging motion of the flight line  Solar Power: Capturing energy from the sun  Peltier Cooler: Using the differences in temperature inside and outside the box to produce energy

4. Mission Requirements Green: Compliant, Yellow: Partially Compliant, Red: Not Compliant RequirementMethodStatus The payload must not exceed a weight of 1.5 kg.Design, Test The flight line should go through the payload's center of gravity.Design, Analysis The payload must be able to survive an impact of at least 16m/s.Design, Test, Analysis Components in payload must be able to survive a temperture of -80˚C.Design, Test Payload must not "cut" through the flight line.Design, Test Payload must survive the "shaking" of balloon burst.Design, Test

5. Fundamental Block Diagram

6. Concept of Operations  Before the launch of the balloon, the payload will be activated via an external switch to provide power to the Logmatic recording software.  During the ascent, the software will gather current readings from the solar panels, the Peltier cooler, and the pendulum system. At a rate of 100 data points per second.  The solar cells will gather light energy from the sun depending on the payload’s orientation (an increase in altitude is expected to produce an increase in energy output).  The Peltier cooler will produce a current as the outside of the payload is cooled by decreasing atmospheric temperatures, and the inside of the payload maintains a reasonably warmer climate.  The pendulum system is expected to produce a current as the turbulence of the payload causes the pendulum to swing the attached magnet over a series of six copper coils.  After payload recovery the SD card will be taken out of the data logger and the flight data will be dumped into excel. The data will be calibrated.

7. Structural Drawings Copper Coils on Board Side View of Box, Solar Panels on Top Pendulum

8. Structural Drawings Battery Hobo, Barometer LogomaticHot Hands Peltier Cooler Copper Plate Pendulum Copper Coil Back View of Box Top View of Box Side View of Box

9. Structure  The box will be made out of ½ inch foam core board which will be cut to the correct dimensions.  The box will be held together with hot glue.  The box will be reinforced with additional foam core board inside.  The outside of the box will be painted black to help absorb the heat from the sun.  PVC pipe will run through the middle of the box for the flight line to go through.  The pipe will be attached to the box using ball bearings.

10. Schematic *There will be resistors added to pull the created power *The grounds will go to the ground on the Logomatic

11. Parts List PartsCompanyModel Solar PanelsFlex Solar Cells, OEM ComponentsRC 7.2-75 Peltier CoolerFrozen CPU437W MagnetK&J Magnetics, Inc.DX0X0-N52 Low Current SensorSparkfun ElectronicsACS712 SD Card LogomaticSparkfun ElectronicsV1.0 Ball BearingsMcMaster-Carr57155K356 Copper SheetWhimsie21-gauge Foam Core BoardHobby Lobby1/2" Lithium Battery 7V

12. Subsystem Overview  Power for the payload will come from a 7V battery.  Data from the flight will be stored at a rate of 100 points per seconds in a SD card.  The payload will have two states, non-active and active. A protected switch will be installed on the outside of the box to activate the payload.  Peltier Cooler-there must be a temperature difference between the two plates.  The inner components (Hobo, battery, logomatic, and SD card) should not get below negative 20˚C.  Pendulum-Must swing in only one dimension.

13. Subsystems-Peltier Cooler  Peltier Cooler- If you apply a voltage to a thermocouple it causes a temperature difference between the two plates.  The Seebeck Effect- If two different metals are connected at two different locations and there is a temperature difference between the two junctions a voltage will be created.  The peltier cooler will be used to create the Seebeck effect and produce a voltage by creating a temperature difference between the plates.  The peltier cooler will be integrated into the box so one side faces out of the box and the other inside.  There will be a copper sheet on the outside of the box to cool that face of the peltier cooler more efficiently.  Hot Hands will be used to heat the other side of the peltier more efficiently inside the box. *http://www.heatsink-guide.com/peltier.htm

14. Subsystems-Pendulum  The pendulum system will use magnetic induction to create power.  A magnet will be placed on the end of the pendulum.  The pendulum will swing back and forth over six copper coils.  The swinging motion of the balloon flight line will drive the pendulum.

15. Test Plans  Cold Test- Dry Ice/Liquid Nitrogen, Styrofoam cooler, four thermo probes, four multimeters, timer  Impact Test- high place to drop box from  Shake Test- Line/string  Time Test- Timer  Flight Simulation Test- Time and Cold test combined with all components running/storing data

16. Cold Test Results Cold Test #1 and #2: The box was suspendered inside a cooler where dry ice was placed. This test was done to see how well a box inside the main box would insulate the electrical components. The dry ice did not cool the box enough and an additional test had to be run.

17. Cold Test Results Cold Test 3: The box was suspended inside a cooler with liquid nitrogen in the bottom of it. The liquid nitrogen cooled the box past the predicted low temperature of the flight. Another test will be run at a later date when all of the components are working.

18. Cold Test Results Peltier Cooler Cold Test #1: This test was run during cold test #3. The results from this test showed that there needed to be a way to stop the peltier cooler from pulling voltage from the system.

19. Impact Test Results  A test box was constructed of the same size and relatively the same weight as the flight box to use for the impact test.  This was done as to not damage any actual flight components before flight.  During actual flight impact the two pieces that need to survive are the Logomatic and SD card.  The test box was dropped of a stair well at different heights.  The impact speed from past flights was calculated to be between 10mph-35mph (4.5m/s-15.5m/s). Flight of StairsImpact speed(m/s)Damage done to Box 17.7none 210.8none 313.3slight dent 415.3slight dent 517.1slight dent

20. Management  Program Manager-Jessica  Project Members-Max, Brent, Ryan, Zach  Faculty- Dr. Bob Walch  Meetings, Tue. 6:00 p.m. and Thus. 7:00 p.m. and scheduled as needed  Budget-$800-$900

21. Conclusion  Issues/Concerns:  The magnet used in the pendulum system will interfere with other components in the box.  The current produced by the pendulum system will be to little to measure at times.  The temperature difference between the two plates of the peltier cooler will “flip-flop” during the descent, which will pull energy instead of produce it. This problem could solved with a diode.  The box will continue to swing in one direction for extended amounts of time, causing the pendulum not to move much. This data from this payload should allow the efficiency of each system to be analyzed during the different sections of the flight.

22. Appendix A Calculations: Impact Test vf^2=vi^2+2gh vf=sqrt(vi^2+2gh) vf=2gh vi=initial velocity=0 m/s g=9.79m/s vf=impact speed h=drop height

23. Appendix B Weight Breakdown ItemWeight (kg) Center Rod.019 Peltier Cooler0.056 Copper Sheet0.3 Box Frame0.315 Magnet0.096 Coils and Base0.217 Pendulum0.03 Solar Cells0.012 Batteries0.12 Inner Box0.086 Ball Bearings Hot Hand Pack Bearings for Rod Total Payload Weight1.165 *Estimated Total Weight=1.4kg

24. Appendix C Box Dimensions 14” 7” 14” 20.5” 10.6”