1. Thomas Buck, Kyle Garner, Alexandra Jung, Quinn Mcgehan, Mark Sakaguchi, and Scott Taylor Team Solkraft Critical Design Review 10/7/2010

2. Mission Overview Objective – To determine the effect of near space conditions on solar cell output. Temperature, light intensity, and altitude. – Expect to prove that there is a relationship between the variables above and the output of two different types of cells. Hypothesis – The monocrystalline cells will outperform the polycrystalline cells, while both cells will perform better in near space than on the ground.

3. Mission Overview Widespread development of solar cells for consumer use is relatively new – 2008- World record set in efficiency (40.8%) Very expensive cell, not consumer friendly – Two main types of consumer oriented cells Monocrystalline/Polycrystalline Why? – Want to know which type of cell is more efficient for consumer use – Want to know which environments are best for maximum energy output

4. Mission Requirements (Level 0) Requirement Number RequirementWhere it comes from M 0.1The solar panels on the BalloonSat shall be exposed to near- space conditions Mission Objective M 0.2Team Solkraft shall measure the internal and external temperature with varying altitude Mission Objective M 0.3Team Solkraft shall measure the light intensity with varying altitude Mission Objective M 0.4Team Solkraft shall test for variations in solar cell output under varying climate conditions Mission Objective M 0.5Team Solkraft shall meet the requirements for the request for proposal

5. Mission Requirements (Level 1) Requirement Number RequirementWhere it comes from M 1.1The solar panels shall be attached to the angled sides of the BalloonSat M 0.1 M 0.4 M 1.2Team Solkraft shall be able to record the altitude of the BalloonSat using data from EOSS GPS M 0.2, M 0.3 M 1.3Team Solkraft shall be able to record and save data during the flight M 0.2, M 0.3, M 0.4 M 1.4Team Solkraft shall maintain a minimum temperature of -10 degrees Celsius. M 0.3, M 0.3, M 0.5 M 1.5Team Solkraft shall program the Arduino microcontroller to record solar cell output data to a micro SD card M 0.2, M 0.3, M 0.4 M 1.6Team Solkraft shall take in-flight pictures using a Canon A5701S camera and save them to the camera’s 2 GB memory card. M 0.5

6. Mission Design: How? Experiment will incorporate three main categories – Photodiodes: Detect light intensity to determine the “amount” of sunlight hitting the panels – Thermistors: On each face to detect temperatures effect on output. – Solar cells: Two different types to determine which one is most efficient All three components will be flowed into multiplexer – Multiplexer will deliver multiple logs per minute – Arduino will log results to MicroSD card to be uploaded into Matlab/Excel

7. Mission Design Ardunio HOBO Mono Cells Poly Cells Photodiodes Thermistors

8. Mission Design 3 9V Batteries SwitchHeater BatteriesSwitchCamera 2 GB Memory Card Multi- plexer ThermistersPhotodiodes Polycrystalline Solar Cells Monocrystalline Solar Cells BatteriesSwitch Arduino 328 2GB Micro SD Card HOBO Power Switch Provided Hardware Sensors Solar Cells

9. Test Plan Structure Tests – Kick Test – Drop Test – Whip Test Freeze Test to make sure thermal systems work Data Test to make sure Arduino and HOBO are recording properly Camera/Imaging Tests Ground Control Tests for: – Solar Panels – Photodiodes – Thermistors

10. Expected Results Monocrystalline will outperform polycrystalline solar cells Solar cells will produce more power in near space – Higher light intensity Less interference with atmosphere – Solar cells less effective at higher temperatures Higher Carnot efficiency of the cell

11. Organization Scott Taylor Team Lead Structure Lead Science Assist Kyle Garner Power Lead Internal Testing Data Analysis Thomas Buck Science Lead Science Testing Structure Assist Quinn Mcgehan Electrical Lead Internal Testing Programming Assist Alexandra Jung Budget//Plan Lead Structure Testing Electrical Assist Mark Sakaguchi Programming Lead Science Testing Data Analysis

12. Biggest Worries The Biggest Worries Of Team Solkraft Are… – Camera failure incl. camera fogging up – Hardware failure i.e. solar panels breaking – Sufficient Programming and debugging – Lack Of Sleep