Balloon Sat Missions to the Edge of Space · Web viewTeam 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

Colorado Space Grant Consortium, The University of Colorado at Boulder Department of Aerospace Engineering Sciences, and the Edge of Space Sciences

Fall 2010

BalloonSat Missions to the Edge of SpaceTeam Solkraft Revision CThomas Buck, Kyle Garner, Alexandra Jung, Quinn McGehan, Mark Sakaguchi, and Scott Taylor

Julie Price, 11/14/10,

Your design section is very thorough, good job. You could improve on some of your data retrieval sections, but overall a nicely laid out paper.

BalloonSat Mission to the Edge of Space Design Document Revision C

TABLE OF CONTENTS1.0 Mission Overview

2.0 Requirements Flow Down

3.0 Design

3.1 Strucutre 3.2 Thermal 3.3 Electronics and Data Collection 3.4 How Team Solkraft Will Achieve Their Mission 3.5 Data Retrieval 3.6 Features 3.7 Illustrations 3.8 Block Diagram 3.9 Parts List 3.10 RFP Requirements

4.0 Management

4.1 Schedule

5.0 Budget

5.1 Budget Management

6.0 Test Plan and Results

6.1 Safety

7.0 Expected Results

8.0 Launch and Recovery

References

2Team Solkraft


1.0 MISSION STATEMENT

The mission of team Solkraft is to test the effectiveness of monocrystalline and polycrystalline solar panels under near space conditions up to approximately 30 km. This will test the solar cells under varying light intensities, temperatures and altitudes. Team Solkraft shall analyze the electrical output of the solar panels to see which type is more effective in a near space environment.

1.1 OVERVIEW

With a planet on the verge of destruction from global warming, the research into alternative energy sources is more important than ever before. One of the most prominent developments made over the past decade is innovative ways to capture energy from the Sun. The use of solar panels on households and businesses has become a popular way to offset energy costs and their potential for the future is even more optimistic. Solar cells are becoming more and more efficient. The National Renewable Energy Lab (NREL) set the record for the world’s most efficient solar cell in 2008 at 40.8%1. Because it is the belief of Team Solkraft that solar cells will become the main source of energy for generations to come, our mission strives to pinpoint the variables that effect solar cell output, specifically in a near-space environment.

The near space environment will provide insights into solar cells being used for stratospheric platforms. Stratospheric platforms are vehicles that operate very high in the atmosphere. These are most commonly thought of for communication relays and access points to provide large areas with wireless broadband. Current stratospheric platforms are run off of fuels or batteries and can only operate for short periods of time. Team Solkraft hopes to explore the possibility of whether using solar panels on stratospheric platforms is a viable option to keep it flying for a longer period of time or even indefinitely.

There is lots of testing of solar cells on the ground and data on how normal ground temperatures affect solar cells. It seems to be agreed upon that under conditions on the ground solar cells decrease in efficiency with an increase in temperature.1 However, there is much less exploration of how solar cells operate under the more extreme conditions of a near space environment.

Team Solkraft shall test how well two different types of solar cells (monocrystalline and polycrystalline) function at different altitudes with varying light intensities and under different temperatures. As a control for the experiment the solar cells will be tested under different temperatures on the ground at a constant altitude before the launch day. The solar panels will be tested on similar weather days with different temperatures and similar temperature with different cloud cover that will provide different light intensities.

3Team Solkraft


Great, very clear


From this initial testing of the solar cells Team Solkraft will compare this data to the data we receive on launch day to see which factor, light intensity or temperature, affects the solar cells. To plot the effectiveness of the solar cells versus altitude we will use data from the GPS attached to the weather balloon after getting approval from EOSS. Light intensity shall also be measured using photodiodes to see how that affects the functionality of the solar cells. Team Solkraft is doing this to analyze the effects of near space on monocrystalline and polycrystalline solar cells. From the information acquired Team Solkraft will decide which type of solar cell is more efficient in a near space environment.

2.0 MISSION REQUIREMENTS

To give the mission the best possible prerequisites to succeed certain requirements need to be fulfilled. Below is the Mission Objective, the Level 0 requirements which come off the Mission Objective and at last the Level 1 requirements which come off the Level 0 requirements. The Level 1 requirements state the actions necessary to complete/fulfill the Level 0 requirements. The relationship between a requirement and its parent requirement (or Mission Objective) is stated in the last column of our table.

OBJECTIVE

The mission of Team Solkraft is to test the effectiveness of different types of solar panels (monocrystalline and polycrystalline) under conditions on the ground and up to near-space conditions of approximately 30 km.

MISSION REQUIREMENTS LEVEL 0

Requirement Number

Requirement Where it comes from

M 0.1 The solar panels on the BalloonSat shall be exposed to near-space conditions

Mission Objective

M 0.2 Team Solkraft shall measure the internal and external temperature with varying altitude

Mission Objective

M 0.3 Team Solkraft shall measure the light intensity with varying altitude

Mission Objective

M 0.4 Team Solkraft shall test for variations in solar cell output under varying climate conditions

Mission Objective

M 0.5 Team Solkraft shall meet the requirements for the request for proposal

M 0.6 Team Solkraft shall make sure no one is hurt during construction and testing

4Team Solkraft


MISSION REQUIREMENTS LEVEL 1

Requirement Number

Requirement Where it comes from

M 1.1 The solar panels shall be attached to the angled sides of the BalloonSat

M 0.1 M 0.4

M 1.2 Team Solkraft shall be able to record the altitude of the BalloonSat using data from EOSS GPS

M 0.2, M 0.3

M 1.3 Team Solkraft shall be able to record and save data during the flight

M 0.2, M 0.3, M 0.4

M 1.4 Team Solkraft shall maintain a minimum temperature of -10 degrees Celsius.

M 0.5

M 1.5 Team 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 1.6 Team 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

M 1.7 Team Solkraft shall record science data to the Arduino Microcontroller

M 0.2, M 0.3 M 0.4

M 1.8 Team Solkraft shall build a structure for the BalloonSat capable of withstanding near space conditions

M 0.1, M 0.5

3.0 DESIGN

3.1 STRUCTURE

To achieve our goal of measuring the functionality of solar panels in a near space environment we will mount eight solar panels on the exterior of a BalloonSat. Four of these cells will be monocrystalline and four will be polycrystalline. The frame of the BallonSat will be a square pyramid with the top cut off so that the 3D structure is formed using four trapezoidal pieces of equal size, one larger square as the base, and one smaller square as the top. This structure will be made out of foam core cut from a single piece in order to help the structural integrity. We will use hot glue and aluminum tape to secure the structure. The structure of the BalloonSat will be attached to a weather balloon using 2.4mm Dacron line by running the line vertically through a non-metal tube at the center. The structure of the BalloonSat will be set in one place along the cord by tying a figure-eight knot in the line at the top and bottom of the BalloonSat. We will also put an American Flag on the BalloonSat to identify it.

3.2 THERMAL

5Team Solkraft


How will you do this? You don’t mention anything about having a heater, insulation, etc.


In order to keep our experiment warm during the flight the satellite will be insulated with foam. In addition to this we will use a heater on the inside of BalloonSat powered by three 9V batteries to help keep the internal temperature of the BalloonSat above -10oC.

3.3 ELECTRONICS/DATA COLLECTION

Data from the solar panels will be recorded using an Arduino Microcontroller hooked up in a circuit with the eight solar panels. We will be able to record all of the solar panels through two analog inputs by using a sixteen channel multiplexer. The multiplexer will alternate from which solar panel the Arduino is taking data. It will do this every _____ seconds however, so we do not need to worry about the time difference as a factor in our data. The voltage will also be recorded with a load on the circuit created by a resistor that is not very affected by temperature to make sure that is not affecting the results of our experiment. Through doing this we can find the power output on the resistor.

The measurements for the temperature will be taken by a HOBO data logger with the internal temperature sensor and an external temperature. This will allow the data to be easily taken off of the data logger and onto a computer for easy evaluation. We will also use four thermistors connected to the Arduino Microcontroller through a multiplexer to record temperature on each side of the BalloonSat. To measure the light intensity we will use a photodiode on each face of the BalloonSat that the solar cells will be on. The data for which will be recorded by our Arduino Microcontroller again using the multiplexer and then going to an analog input. In addition to the data we collect using sensors on our satellite we will also collect altitude data from the GPS attached to the weather balloon at the end of the flight string after getting permission from EOSS.

3.4 HOW TEAM SOLKRAFT WILL ACHIEVE OUR MISSION

First we will look at the structure of our satellite. Team Solkraft will design the sides of our pyramid structure to fit four of the solar cells which are 76mm x 83mm x 6mm, one on each side. Team Solkraft will then cut out a template of the satellite out of foam core and assemble the structure using hot glue and aluminum tape. Before integration of the solar panels into the structure Team Solkraft shall first test each one by connecting them to a voltmeter and testing each one under different amounts of light to be sure that they are working. The next step is to integrate our solar cells by soldering the positive side to a resistor and then attaching a lead to that resistor going to the multiplexer input. The negative side will be connected to the ground of the microcontroller. The microcontroller will turn the analog signals into digital and give a voltage reading of the solar cells. Also along the outside of the satellite we will mount a photodiode on each side to measure light intensity positioned between the two solar cells. This will help us determine which solar cell is facing the sun based on the intensity and we will use that specific panel’s voltage reading. We will then start mounting the components on the inside of the satellite such as the heater, HOBO, and camera. After learning how to solder in class,

6Team Solkraft



Team Solkraft will assemble the heater and place it in the satellite ensuring that when the BalloonSat passes through the tropopause that the circuits remain at an operable temperature. Next the camera will be mounted our camera after adjusting the timing program to take pictures approximately every 20 seconds. Team Solkraft will cut out a hole for the lens in one of the sides, this will ensure ventilation to the satellite to help prevent any condensation build up. Insulation will also surround the lens from the side back to the camera so that the rest of the satellite is still insulated keeping the heat in. Our HOBO will have its external temperature sensor mounted through another hole in one of the sides of the satellite so we will have a comparable internal and external temperature reading.

3.5 DATA RETRIEVAL

Team Solkraft BalloonSat will have an Arduino microcontroller to record the voltage output of the solar cells. This data will then be transformed from an analog to digital signal to be logged and stored for later collection on either the flash memory of the microcontroller or an external memory card hooked up to the USB port of the microcontroller. Therefore, the means of data retrieval will involve transferring the data from the microcontroller to a computer for processing after the BalloonSat has returned to the ground.

The photodiode sensors will also produce a voltage based on the light intensity and the amount of voltage from those sensors will correspond to the light intensity. Team Solkraft will record this in the Arduino microcontroller.

The data will then be analyzed as voltage output as a function of altitude, and also temperature. The altitude data will be retrieved from the GPS attached to the flight string, and the external temperature will be taken from the HOBO logger onboard our BalloonSat. It will then be possible to determine the efficiency of the cells as a function of altitude and temperature. The data analysis will be done using Excel.

3.6 FEATURES

Photodiodes

Photodiodes will measure the light intensity from the sun and convert it into voltage that will be read by the microcontroller. Team Solkraft will use this to determine specific measurements for the light intensity as it changes throughout the flight.

Solar Panels

The solar panels are our experiment. With them Team Solkraft will determine what affects their functionality in a near space environment. We will also see which type is more effective.

7Team Solkraft


Are you comparing the data to the external temperature recorded by the HOBO or by the thermistors?


Structure

The structure will allow Team Solkraft to use the solar cells more efficiently because they will be more directly angled towards the sun. The trapezoidal shape will also help the structural integrity when the BalloonSats land because all of the parts inside the BalloonSat will give it a lower center of gravity making it more stable and less likely to land on a side damaging a solar cell.

3.7 PICTURES

8Team Solkraft


Your drawing needs component dimensions as well as box dimensions


9Team Solkraft

Heater

Arduino (Velcroed to wall of Balloonsat)

HOBO (Velcroed to wall of Balloonsat)

HOBO External Temp Sensor

Polycrystalline Cell

Monocrystalline Cell


10Team Solkraft

90 mm220 mm

110 mm

128 mm


3.8 BLOCK DIAGRAM

11Team Solkraft

3 9V Batteries Switch Heater

Batteries Switch Camera 2 GB Memory Card

HOBO

Multi-plexer

Thermisters

Photodiodes Polycrystalline Solar Cells

Monocrystalline Solar Cells

Power

Switch

Provided Hardware

Sensors

Solar Cells


3.9 FINAL PARTS LISTPart and where it is from ReferenceSix Monocrystalline solar panels from Edmund’s Scientific

http://scientificsonline.com/product.asp_Q_pn_E_3039808

Fourteen Polycrystalline solar panels from The Electronic Goldmine

http://www.goldmine-elec-products.com/prodinfo.asp?number=G16397

Six Photodiodes from West Florida components

http://www.westfloridacomponents.com/mm5/merchant.mvc?Screen=PROD&Store_Code=wfc&Product_Code=LED060&Category_Code=

Arduino Duemilanove Microcontroller Starter Kit from Sparkfun Electronics

http://www.sparkfun.com/commerce/product_info.php?products_id=9952

9V to barrel jack adapter from Sparkfun Electronics


5 Thermistors from Sparkfun Electronics http://www.sparkfun.com/commerce/product_info.php?products_id=250

Micro SD Shield from Sparkfun Electronics


Multiplexer breakout board from Sparkfun Electronics


Foamcore from Colorado Space GrantInsulation from Colorado Space GrantCanon A5701S from Colorado Space GrantHOBO Datalogger from Colorado Space GrantHeater from Colorado Space Grant9V Batteries from Colorado Space Grant

3.10 HOW TEAM SOLKRAFT WILL MEET THE RFP REQUIREMENTS

12Team Solkraft

Batteries Switch Arduino 328

2GB Micro SD Card



















1. Design shall have additional experiment(s) that collects science data and teams must analyze this data. Team Solkraft additional experiment will collect data as voltage readings from solar panels that Team Solkraft are testing. See 1.0 Mission Overview and 3.0 Design

2. After flight, BalloonSat shall be turned in working and ready to fly again.Team Solkraft will make sure the BalloonSat is able to withstand the rigors of flight through testing. See 6.0 Testing

3. Flight string interface tube shall be a non-metal tube through the center of the BalloonSat and shall be secured to the box so it will not pull through the BalloonSat or interfere with the flight string. (See flight string attachment diagram at the end of this document.) See 3.1 under Design

4. Internal temperature of the BalloonSat shall remain above -10˚C during the flight.Team Solkraft will use a heater and insulation to keep the BalloonSat above -10oC. See 3.2 under Design.

5. Total weight shall not exceed 850 grams.Team Solkraft will budget our weight and plan so that our experiment shall not exceed 850 grams. See 3.0 Design and 5.0 Budget.

6. Each team shall acquire (not necessarily measure) ascent and descent rates of the flight string.Team Solkraft shall get permission from EOSS to use the data from the attached GPS.

7. Design shall allow for a HOBO H08-004-02 (provided) See 3.0 Design

8. Design shall allow for external temperature cable (provided)See 3.0 Design

9. Design shall allow for an Canon A570IS Digital Camera (provided)See 3.0 Design

10. Design shall allow for an active heater system weighing 100 grams with batteries and id 10x50x50mm (provided). Dimensions do not include 2 x 9 volt batteries.See 3.0 Design

11. BalloonSat shall be made of foam core (provided).See 3.0 Design

12. Parts list and budget shall include spare parts.See 5.0 Budget.

13. All BalloonSats shall have contact information written on the outside along with a US Flag (provided).Team Solkraft will put US Flag and contact information on bottom of satellite.

14. Proposal, design, and other documentation units shall be in metric.Yes

15. Launch is in November 6, 2010. Time and location: 6:50 AM in Windsor, CO. Launch schedule will be given later. Everyone is expected to show up for launch. Only one team member is required to participate on the recovery. Launch and recovery should be completed by 3:00 PM.Team Solkraft will all plan ahead to be at launch.

16. No one shall get hurt.See 6.1 Safety under Testing

13Team Solkraft


17. All hardware is the property of the Gateway to Space program and must be returned in working order end of the semester. Team Solkraft shall make sure the BalloonSat is able to withstand the rigors of flight through testing. See 6.0 Testing

18. All parts shall be ordered and paid by Chris Koehler’s CU Mastercard by appointment to minimize reimbursement paperwork. All teams shall keep detailed budgets on every purchase and receipts shall be turned in within 48 hours of purchase with team name written on the receipt along with a copy of the Gateway order form (HW 04). See 5.0 Budget

19. All purchases made by team individuals shall have receipts and must be submitted within 60 days of purchase or reimbursement will be subject to income taxes.See 5.0 Budget

20. Have fun and be creative.Will do.

21. Absolutely nothing alive will be permitted as payloads, with the exception of yellow jackets, mosquitoes, fire ants, earwigs, roaches, or anything you would squish if you found it in your bed.Nothing on our satellite will be alive.

22. Completion of final report (extra credit if team video is included)

4.0 MANAGMENT

4.1 SCHEDULE

14Team Solkraft

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/Planning

Lead Structure Testing Electrical Assist

Mark Sakaguchi

Programming Lead

Science Testing Data Analysis


You should show what has already been completed, what is late, etc.


Team Solkraft will have a team meeting every Tuesday and Thursday at 6:00 PM. Extra meetings will be organized or rescheduled as needed. The meetings will always take place in the ITLL building in a reserved study room.

Date Tasks9/20/10 All Hardware needed addressed9/21/10 Hardware Order Form processed10/1/10 Design complete10/5/10 Revision A/B Due10/6/10 Start Construction finish prototype10/8/10 Start Testing (Whip Test, Drop Test, Kick

Test)10/09/10 Acquire all hardware and materials10/11/10 Finished with all structure testing10/12/10 Initial Programming of Arduino10/14/10 Start Construction of Electrical systems10/19/10 Start Interfacing of systems10/21/10 Test Electronics10/25/10 BalloonSat. Built10/26/10 Final Critique10/29/10 Simulation Test10/29/10 All testing complete11/1/10 Troubleshooting complete11/2/10 Revision C due11/5/10 BalloonSat Weigh-in and Turn in11/6/10 Launch Day11/8/10 Post-launch Data Review Complete11/30/10 Final Presentations12/4/10 Revision D due12/7/10 BalloonSat Hardware Turn In

5.0 BUDGET

Name Purpose Dimensions (mm)

Mass (g)

Cost Where We get it

Canon A5701S Camera

Take Pictures 45x75x90 220 Provided Space Grant

15Team Solkraft


HOBO Datalogger Measure/record temperature and humidity

68x48x19 30 Provided Space Grant

Monocrystalline Solar Panels (6: 4 used, 2 extra)

Experiment 42x41x6 ~6* (each)

$4.95 (each)

Edmund’s Scientific

Polycrystalline Solar Panels (6)

Experiment 57x29x6 ~5* $1.49 (each)

The Electronic Goldmine

Photodiodes (6) Measure light intensity 4 $.40 West Florida Components

Heater Maintain internal temperature

10x50x50 100 Provided Space Grant

9V Batteries (4+extra for tests)

Provide Power 48x25x15 34 (each)

~ $3 (each)

Amazon.com

Arduino DuemilanoveMicrocontroller

Record voltage readings from solar cells and light intensity readings from photodiodes

69x53 40 $59.95 Sparkfun electronics

9V to barrel jack adapter

Power Microcontroller ~10 $2.95 Sparkfun

Switches Turn on/off electronics Provided Spacegrant/with Arduino

Connecting Wires Integrate electronics Provided With ArduinoResistors Set up circuit for solar

panelsProvided With Arduino

Thermister (5 one comes with Arduino)

Record Temperature 5 $1.95 Sparkfun

Micro SD Shield Can put micro SD card into Arduino for extra memory

53x52 10 $16.95 Sparkfun

16 Channel Multiplexer (1)

Make additional readings with analog inputs on Arduino

8x9 $.95 Sparkfun

Multiplexer breakout board (1)

40x18 $4.95 Sparkfun

Foamcore Structure of satellite (see diagrams) ~150 Provided Space GrantShipping ~$20Totals 780 $176.54

*Couldn’t find the mass of these particular solar cells so estimated using mass of similar ones.

**For those which dimensions and mass are blank, are not sure yet how much/many it will be, but Team Solkraft believe it will not put us over the weight limit.

5.1 BUDGET MANAGEMENT

The budget will be managed by Alexandra Jung. Team Solkraft will keep an up to date account of spending and plan for what the experiment will need so that Team Solkraft does not go over budget. Right now Team Solkraft has a large surplus in the budget and we will try to keep a

16Team Solkraft


surplus in case there is anything the experiment need to order at the last minute such as a replacement part of something that has been forgotten.

6.0 TESTING

Team Solkraft will make testing a priority to insure that every component will successfully contribute to the overall mission. Team Solkraft will start by making sure that the structure is capable to handle the stresses exposed during takeoff, burst, and landing. Team Solkraft shall do this by performing several structural tests on a similarly massed dummy satellite. The dummy satellite will have rocks inside of the structure of similar mass to the components but will not necessarily be in the exact position the components will be in.

1. Kick Test-The dummy was kicked down a flight of stairs to test overall strength.

Structure held well during test with only minor damages to the corners of the BalloonSat.

2. Drop Test-The dummy was dropped two stories from the ITLL second story balcony to insure the structure is capable of handing the stresses related to various landing scenarios.

The BalloonSat remained intact except from minor damages to the foamcore because the structure landed on the flight tube. Team Solkraft anticipates that this will not be a problem because there will be other satellites above and below on the flight string so there will be no direct impacts as seen in the test.

3. Whip Test-The dummy was swung about a string to test the strength of vulnerable points on the spacecraft, such as the flight string tube, corners/joints, and access points. This

17Team Solkraft


also tested whether our system to keep the BalloonSat attached to the flight string was strong enough. This will simulate the forces exerted on the satellite during burst.

This test was successful with the flight tube withstanding the forces.

Secondly, Team Solkraft will perform various tests on the internal components of the spacecraft. The tests to be performed include:

1. Freeze test- This test will simulate the radical temperature changes Team Solkraft’s payload will go through on its journey to near-space. In this test, Team Solkraft will put our fully functional satellite into a cooler with dry ice. To correctly simulate mission conditions, the payload will be left in the cooler for a little over an hour. The data taken during the cold test will only be temperature data due to the fact that there will be no light in the cooler.

18Team Solkraft


Your plot should have some explanation following it. What was your target temperature of the cooler?


2. Data tests- Team Solkraft will perform tests to verify that all systems are functioning correctly and the spacecraft is capable of taking data. To simulate this, Team Solkraft shall power up the payload as if it were launch day, and expose it to various environmental conditions to insure the HOBO is collecting and logging data correctly. If any issues arise, we will test individual components to make sure they are working properly.

19Team Solkraft

1. Cold test with dry ice covered

2. Cold test with dry ice uncovered BallonSat

3. Cold test in freezer

3

2

1


0 5 10 15 20 250

0.02

0.04

0.06

0.08

0.1

0.12

Voltage Readings of Solar Cells by Arduino

MonocrystallinePolycrystalline

Time (s)

Volta

ge

Data from a general systems test in low light. Readings are from one side of the BalloonSat. At Time~12 seconds the BalloonSat was moved into the shade. A corresponding drop was seen so we know both solar cells are giving correct readings. Also from this test we can see that the monocrystalline cells have a consistently higher voltage at a constant temperature on the ground.

3. Camera/imaging tests- These tests insured that our camera was working properly and is ready for launch day. This was accomplished by setting the programming to trigger the camera to start at certain intervals, and making sure those intervals are consistent throughout the picture taking process.

We tested the camera outside and inside the satellite to ensure that the lens of the camera was not obstructed inside. The final position of the camera gives us a clear picture outside the satellite.

20Team Solkraft


In addition, Team Solkraft will initiate tests on the experiment portion of their mission, to insure that the experiment is capable of operation throughout the flight. These tests include:

1. Control tests- Team Solkraft will perform different ground tests to serve as a control for the experiment. For instance, because we are testing the variation of solar cell efficiency in near-space conditions, one of our control experiments will be to expose the solar cells to various temperature differences on the ground. This will enable us to possibly rule out temperature as a variable in the efficiency in solar cell output, and move us toward investigating other possible variables such as altitude.

Team Solkraft will also order extra parts to insure that the payload is capable of flying on launch day, regardless of the possible misfortunes our testing process may have on it.

6.1 SAFETY

Team Solkraft will do its best at maintaining the safety of its team members and all bystanders. We will be sure to follow the safety instructions given to us when Team Solkraft starts soldering. Through all of the testing Team Solkraft will use common sense. Also, for all tests at least two team members will be present. For the drop test we make sure the drop zone is clear and give the person dropping the correct signal to proceed. We will make sure the rope/wire is very secure before starting the whip test and we will clear a safe radius from the person ‘whipping.’ The stair well and sides and bottoms of it will be clear of people before we start the stair test just in case the satellite goes over the side. The hot glue gun will be operated very carefully and with finesse. The glue will be given time to cool. The exacto blade will be handled with one hand and with the other a good distance to the side. We will never operate it with rapid motions, just slow careful cuts.

7.0 EXPECTED RESULTS

The monocrystalline cells will outperform the polycrystalline cells, while both cells will perform better in a near space environment than on the ground. Monocrystalline cells are more expensive to manufacture than polycrystalline, but monocrystalline cells are known to be more efficient than polycrystalline when used on the ground.2

Team Solkraft expects that the solar cells will perform more efficiently in the near space environment for a multitude of reasons. First, team Solkraft expects that the atmosphere interferes with the light from the sun that hits Earth and causes the intensity of the light to decrease as it goes through the atmosphere. Therefore, at higher altitudes the solar cells will produce a higher voltage output because there is a higher light intensity. This was the case with the control tests on the ground. This can be seen in the graph of voltage readings in section 6.0 under Data Tests.

Second, team Solkraft expects that the solar cells will function more efficiently at the colder temperatures of near space because of the increase in the Carnot efficiency of the cell. This

21Team Solkraft


happens because the temperature difference of the source of light, the sun, and the solar cell are greater as the temperature of the solar cell and its surroundings decrease.3 More control test are needed to determine how much temperature affects the voltage output of the solar cells. Team Solkraft will perform more control tests in the days leading up to launch.

Team Solkraft expects that the lower temperatures and higher light intensities of the upper atmosphere will affect the voltage output of the solar cells. If Team Solkraft’s assumptions our correct that the lower temperatures will increase solar cell output the data will show a peak in voltage as the BalloonSat goes through its coldest point, the tropopause. However, light intensity is also a factor and from the data it can be determined whether the light intensity or temperature affect it more based on whether the peak voltage is at the tropopause or at the maximum altitude.

8.0 LAUNCH AND RECOVERY

Launch Procedure

1. BalloonSat will be attached to flight string before launch day by Chris Koehler2. HOBO will start recording automatically for 6:45 AM on November 63. Team Member A will flip switches to start the camera, heater and Arduino. (Camera

switch will be flipped back to “off” position after the wires have been short circuited to start the camera and will therefore not be a drain on the battery)

4. Team Member B will hold Team Solkraft’s BalloonSat awaiting release of weather balloon

5. As weather balloon is released Team Member B will move forward so a smooth launch will be achieved

Recovery

1. Quinn McGehan will drive Team Solkraft to the recovery site2. After recovering the BalloonSat the heater and Arduino switches will be turned off.

Data Retrieval

The science data will be recorded to a microSD card connected to the Arduino microcontroller. The data will be in the form of a .txt file. In the data will be the time that has passed since the microcontroller was turned on, the input of the multiplexer that the Arduino is currently taking data, and a voltage reading. This file will then be opened in Excel. The programming of the Arduino allows for tabs between each data value and a return after each line of data so that when the file is imported into Excel it will be in three columns: time, input number, voltage. The data can then be split up into each of the 16 inputs based on the input number in the second column. The voltage will be given on a scale from 0-1023 which corresponds to 0-5V DC. The relative voltage coming through the thermistors will change because the resistance changes based on the temperature. The voltage from the photodiodes corresponds to relative light intensity. The

22Team Solkraft


voltage output from the solar panels can be used to find their power output based on the resistance of the circuit which we will know based on the resistor we connect.

The HOBO data will be stored on the HOBO’s internal memory and can be analyzed by using Boxcar.

The pictures from the camera will be stored on the camera’s SD card.

REFERENCES

1. NREL http://www.nrel.gov/news/press/2008/625.html2. Solar Server http://www.solarserver.com/knowledge/basic-knowledge/photovoltaics.html3. Projects at the Solar Energy Group

http://www.physics.usyd.edu.au/app/solar/about/projects.html

BIOS

Scott Taylor

Scott is a freshman in Aerospace Engineering at University of Colorado at Boulder. He was born August 29, 1992 in Boulder, CO. He likes to kayak and mountain bike in his free time. In the future Scott hopes to work for NASA or a private space company with human spaceflight and spacecraft propulsion.

Phone: 303-945-1488Address: 9016 Crosman Hall. Boulder, CO 80310-0010Email: [email protected]

Kyle Garner

Kyle is a freshman in Aerospace Engineering at the University of Colorado at Boulder. Born in Longmont, CO, he enjoys the outdoors and playing video games when he has some extra time. Kyle was actively involved in debate in high school, and enjoys judging at meets and helping out the team however he can. In the future, Kyle dreams of working with NASA on human spaceflight projects.

Phone: 720-210-8615Address: 9012 Aden Hall. Boulder, CO 80310-0002Email: [email protected]

Mark Sakaguchi

Mark was born on July 23, 1992 in Denver Colorado. He is a freshman at the University of Colorado at Boulder and is studying Aerospace Engineering. Mark likes to play golf and is an

23Team Solkraft

http://www.physics.usyd.edu.au/app/solar/about/projects.html

http://www.solarserver.com/knowledge/basic-knowledge/photovoltaics.html

http://www.nrel.gov/news/press/2008/625.html


active member in the Japanese drumming group, Denver Taiko. In the future Mark wants to be working for Lockheed Martin or working for NASA as an aerospace engineer.

Phone: 720-281-3545Address: 9008 Andrews Hall. Boulder, CO 80310Email: [email protected]

Quinn McGehan

Quinn is a jovial fellow, who was born in Fairfield, California on April 25th 1992. He has been raised almost completely in Boulder and attended Fairview High School. He currently attends CU- Boulder, majoring in Aerospace engineering. He greatly enjoys ping-pong, sports, and movies. Quinn wants to one day go to space himself, and in the future hopes to work for NASA.

Phone: 303-877-7962Address: 9057 Aden Hall. Boulder, CO 80310Email: [email protected]

Anna Alexandra Jung

Alexandra is an international student from Copenhagen, Denmark from where she also has a B.Sc. in astrophysics. She plans on doing her masters in aero- and astrospace engineering, which is why she came to Boulder to get as much experience as possible within this field.

Born in Dragør just outside of Copenhagen on December 6th 1986, she has always aimed for the stars and wanted to become an astronaut. The dream is still alive, but all she knows for sure is that she wants to work with human spaceflight in one way or another.

Being a former elite athlete she enjoys swimming, skiing and athletics in general. Besides that, music and socializing takes up a lot of her time. And she loves to travel, meeting new people and learn about different cultures.

Address: 1024 Adams Cir Apt. F-224.Boulder, CO 80303Phone: 720-278-4973Email: [email protected]

Thomas Buck

Thomas was born in San Antonio, Texas, but moved to Colorado when he was three. Thomas went to Thomas Jefferson High School and decided to go to CU Boulder, because of the Aerospace program, the campus and the people. He is a fun guy to hang around with and has a good sense of humor. In his free time Thomas enjoys snowboarding, playing the guitar, shooting some hoops and adventuring through Colorado’s vast and beautiful landscape.

Phone: 303-517-7760

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Address: 9055 Aden Hall. Boulder, CO 80310.Email: [email protected]

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Documents

Balloon Sat Missions to the Edge of Space · Web viewTeam 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