Balloon Sat Missions to the Edge of Space

Balloon Sat Missions to the Edge of Space

BalloonSat Mission to the Edge of SpaceProposal

[CK1]

[CK2]


Mission[CK3] Statement[CK4]

Solar panels have a wide variety of uses both on the ground and in space. Because of this, the mission of team Solkraft is to test the effectiveness of solar panels under near-space conditions of approximately 30 km. This will help us tell under what conditions a solar cell will function most effectively; therefore, we can find the most efficient way to use [CK5]a solar cell.

Overview

We will test how well the solar cells function at different altitudes with varying light intensities and under different temperatures[CK6]. As a control for the experiment we will also test the solar cells under different temperatures on the ground at a constant altitude[CK7]. To plot the effectiveness of the solar cells versus altitude we will use data from the GPS attached [CK8]to the weather balloon. We will also measure light intensity using photodiodes to see how that affects the functionality of the solar cells. From this information we can determine, for example, if it is more effective to use a solar cell on the ground or if it is more feasible to get power from solar cell in space[CK9].

Technical overview

Structure[CK10]

To achieve our goal of measuring the functionality of solar panels in a near space environment we will mount 4 solar panels [CK11]on the exterior of a balloonsat. The frame of the balloon sat will be a square pyramid with the top cut off so that the 3D structure is formed using 4 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.

Thermal

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.

Electronics/Data Collection

Data from the solar panels will be recorded using an Arduino Microcontroller [CK12]hooked up in a circuit with the 4 solar panels. The voltage will also be recorded with a load on the circuit [CK13]created by a resistor. Through doing this we can find the power output on the resistor. The measurements for the temperature [CK14]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. To measure the light intensity we will use photodiode[CK15]. The data for which will be recorded by our Arduino Microcontroller. In addition to the data we collect using sensors on our satellite we will also collect data from the GPS attached to the weather balloon at the end of the flight string.

How we will achieve Our mission

First we will look at the structure of our satellite. We 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. We will then cut out a template of the satellite out of foam core and assemble the structure using hot glue and aluminum tape. Before we integrate the solar panels into the structure we will 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 in to integrate our solar cells, in parallel to our microcontroller which will turn the analog signals into digital and give us a voltage reading of all of the solar cells. Also along the outside of the satellite we will mount a photodiode next to each solar panel on each side to measure light intensity. 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, we will assemble our heater and place it in the satellite next to the microcontroller ensuring that when we pass through the tropopause that our circuits remain at an operable temperature. Next we will mount our camera after adjusting the timing program to take pictures approximately every 20 seconds. We 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[CK16]. 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.

Illustrations[CK17]

Ballon Sat expanded top new jpg

Hardware/Budget

Name / Purpose / Dimensions (mm) / Mass (g) / Cost / Where We get it
Canon A5701S Camera / Take Pictures / 45x75x90 / 220 / Provided / Provided
HOBO Datalogger / Measure/record temperature and humidity / 68x48x19 / 30 / Provided / Provided
Solar Panels (6: 4 used, 2 extra) / Experiment / 76x83x6 / ~6* (each) / $5.95 (each) / Edmund’s Scientific
Photodiodes (6) / Measure light intensity / 4g / $.40 / West Florida Components
Heater / Maintain internal temperature / 10x50x50 / 100 / Provided / Provided
9V Batteries (5) / Provide Power / 48x25x15 / 34 (each) / ~ $3 (each) / Amazon.com
Arduino Duemilanove
Microcontroller / Record voltage readings from solar cells and light intensity readings from photodiodes / 69x53 / 40 / $29.95 / Sparkfun electronics
9V to barrel jack adapter / Power Microcontroller / ~10 / $2.95 / Sparkfun
Switches / Turn on/off electronics / Provided / Provided
Connecting Wires / Integrate electronics / Provided / Provided[CK18]
Resistors / Set up circuit for solar panels / Provided / Provided[CK19]
Foamcore / Structure of satellite / (see diagrams) / 100-200 / Provided / Provided
Totals / 684-784 / $91[CK20]

*Couldn’t find the mass of these particular solar cells so we estimated using mass of similar ones.[CK21]

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

Testing[CK22]

Team Solkraft will make testing a priority to insure that every component will successfully contribute to the overall mission. We will start by making sure that the structure is capable to handle the stresses exposed during takeoff, burst, and landing. We will do this by performing several structural tests on a similarly massed dummy satellite:

  1. Kick Test-The dummy will be kicked down a flight of stairs to test overall strength.
  2. Drop Test-The dummy will be dropped several stories to insure the structure is capable of handing the stresses related to various landing scenarios.
  3. Whip Test-The dummy will be 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 will simulate the forces exerted on the satellite during burst.

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 our payload will go through on its journey to near-space. In this test, our team 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.
  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, we will 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.
  3. Camera/imaging tests- These tests will insure that our camera is working properly and is ready for launch day. This will be 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.

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, including altitude and relative humidity.
  2. Voltmeter tests- This test will detect any deficiencies in our capabilities to record and log variations in voltage output from the solar cells. The team will hold up the satellite to various intensities of light to insure that the voltmeter and onboard computer are correctly receiving and recording data. This will also enable us to detect any limits in our voltmeter and software, to see whether the system can still accurately record high amounts of data. We will perform this by exposing the cells to as much light as possible to see if there is any maximum limitations in the system.

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. [CK23]

Safety[CK24]

Team Sol Kraft 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 we start soldering. 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.

Features

Photodiodes

Photodiodes will measure the light intensity from the sun and convert it into voltage that will be read by the microcontroller. We 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 we will determine what affects their functionality in a near space environment.

Structure

The structure will allow us 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.

Data Retrieval[CK25]

Our 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. We will record this in the 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.

Block Diagram[CK26]

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Schedule and management

Team Sol Kraft will have a team meeting every Tuesday at 6:30 pm and Sunday at 12:00 pm[CK27]. 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 / Tasks[CK28]
9/20/10 / All Hardware needed addressed
9/21/10 / Hardware Order Form processed
10/1/10 / Design complete
10/5/10 / Revision A/B Due
10/09/10 / Acquire all hardware and materials
10/11/10 / Start building structure
10/17/10 / Start preliminary tests on structure
10/25/10 / Balloon Sat. Built
10/26/10 / Final Critique
10/29/10 / Simulation Test
10/29/10 / All testing complete (whip test, cold test, etc.)
11/1/10 / Troubleshooting complete
11/2/10 / Revision C due
11/5/10 / BalloonSat Weigh-in and Turn in
11/6/10 / Launch Day
11/8/10 / Post-launch Data Review Complete
11/30/10 / Final Presentations
12/4/10 / Revision D due
12/7/10 / BalloonSat Hardware Turn In

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: 303-945-1488

Address: 9016 Crosman Hall. Boulder, CO 80310-0010

Email:

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: 720-210-8615

Address: 9012 Aden Hall. Boulder, CO 80310-0002

Email:

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 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: 720-281-3545

Address: 9008 Andrews Hall. Boulder, CO 80310

Email:

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: 303-877-7962

Address: 9057 Aden Hall. Boulder, CO 80310

Email:

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 80303

Phone: 720-278-4973

Email:

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

Address: 9055 Aden Hall. Boulder, CO 80310.

Email:

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Team Solkraft

[CK1]Check your spelling

[CK2]Good proposal. You did a good job answering most of the questions and your mission is OK. I would like to see you expand what it is you are doing (see comments below). I would also like you to do more on your WHAT and WHY. Overall this could be a good project if you expand your mission.

[CK3]These first two sections should contain more information. The WHY and WHAT could be better. This sections should be close to 1 page. You should consider rethinking WHY you are doing this. What is your motivation? What do you hope to discover? Perhaps you could consider using different types of solar cells as part of your experiment.

[CK4]Nice formatting.

[CK5]Most folks know the best way to use cells. You need a different motivation.