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Light Intensity and the Power…of Love 2007

Colorado Space Grant Consortium

GATEWAY TO SPACEFALL 2007

DESIGN DOCUMENT

Team McLovin

Written By: Deniz Bertuna, Tyler Drake, Jason Hohl, Gavin Kutil, Ryan Quakenbush, Gauravdev Singh Soin

December 3, 2007Revision D

Revision Description DateA Conceptual Design Review October 4, 2007

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B Preliminary Design Review October 17, 2007C Critical Design Review November 9, 2007D Analysis and Final Report December 3, 2007

Revision Log

Table of Contents1.0 Mission Overview…………………………………………………………………………….4

1.1 Objective

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1.2 Experiments1.3 Expected Results

2.0 Requirements Flow Down……………………………………………………………………53.0 Design………………………………………………………………………………………..7

3.1 Parts3.2 Drawings3.3 Functional Block Diagram3.4 Final Part List

4.0 Management…………………………………………………………………………………114.1 Organizational Chart4.2 Schedule

5.0 Budget……………………………………………………………………………………….135.1 Mass5.2 Money

6.0 Test Plan and Results………………………………………………………………………..146.0.1 Stair Test6.0.2 Whip Test6.0.3 Drop Test6.0.4 Cooler Test6.0.5 Photometer Testing and Calibration6.1 Testing Results

6.1.1 Stair Test6.1.2 Whip Test6.1.3 Drop Test6.1.4 Flammability Test6.1.5 Conductivity Test6.1.6 Photometer Test6.1.7 Camera Test6.1.8 Cooler Test6.1.9 HOBO Test

7.0 Expected Results…………………………………………………………………………….208.0 Launch and Recovery……………………………………………………………………….21

8.1 Plan for Launch and Recovery8.2 Account of Launch and Recovery

9.0 Results and Analysis ……...…………………………………………………………………2210.0 Ready for Flight ……………………………………………………………………………2411.0 Conclusion and Lesson Learned …………………………………...………………………2412.0 Message to Next Semester …………………………………………………………………25

1.0 Mission Overview

1.1 Objective

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The objective of our team mission is to test and build a satellite that will be sent to approximately thirty kilometers and measure light intensity at different atmospheric levels and take high quality images. The team wishes to further the studies of light intensity being performed by Professors Brown and Fesen in their efforts to create a low budget, high quality, near space platform for astronomical purposes. A near space telescope would be far more cost efficient and a lot easier to maintain than a space telescope such as Hubble. The system of maintenance for the Hubble is less practical because it takes far more time to prepare and send a system to aid it in repair. Additionally, the images would be more crisp and defined than images taken from earth. That is why the Hubble is so successful. Images taken from earth has much atmospheric interference, so a happy medium is a near space telescope, it is simply more practical.

1.2 ExperimentsThe light intensity experiment will be using one light sensitive photo diode placed in the upper corner of the cube at a slant of forty five degrees. A PVC pipe will direct sunlight onto a specific area in the diodes which will then use this light to analyze the different regions of the light spectrum.

Our group wishes to discover if light at near space altitude is not so intense as to dissuade us from obtaining Hubble type quality images.

A high mega pixel digital camera will be used to take high quality pictures of the upper atmosphere as well as of the journey during ascent and descent.

1.3 Expected ResultsThe main expectations are to formulate an average value of light intensity at various altitudes to further promote the research of Professors Brown and Fesen in hopes of advancing the field of low cost near space astronomy. Our results will provide data that will be used to decide whether or not Hubble quality images provided from near space astronomy will be possible during day light hours.

We are hoping to obtain data that will indicate low levels of light intensity that has been previously filtered of ultra-violet interference. These low levels will indicate that it may be possible to establish a near space telescope. It will prove both to us and to others alike that it is more practical than both ground level telescopes and telescopes that are in outer space. Both cost and imagery will be preferable at the given altitude that we determine to be most efficient.

2.0 Requirements Flow DownTo launch and recover a BalloonSat sent to an altitude of 30 kilometers, and perform scientific experiments to measure light intensity up to that altitude to aid in the determination of whether or

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not is practical to establish a near space telescope versus ground level telescopes and outer space telescopes.

Mission Statement To launch and recover a BalloonSat sent to an altitude of 30 kilometers, and perform scientific experiments to measure light intensity up to that altitude; while periodically capturing photographs.

Mission Objectives 1. Construct a BalloonSat to test light intensity at high altitudes.

2. Measure light in the infrared frequency.3. Record temperature of the photodiode.4. Obtain high altitude photographs

Level 0 (Objective Requirements)

derived from Mission Objectives

0.1) Construct a BalloonSat with a budget of $200.00, and a weight less than or equal to 800 grams.

0.2) The Balloonsat will better our understanding of light intensity between altitudes of 15 and 30 kilometers.

0.3) The Balloonsat will be constructed and ready to fly by November 10, 2007.

0.4) Measure light in the infrared frequency in nanometers at different atmospheric altitudes.

0.5) Track the temperature (˚C) of the photodiode to correctly evaluate dark current noise effects on data.

0.6) Obtain high quality images of the curvature of the earth at 30 kilometers.

0.7) Keep the inside of the BalloonSat above 0 ˚C

Level 1 (System Requirements)

derived from level 0 requirements

1.1) The Balloonsat, excluding the photometer, must be maintained at an optimal temperature of 25 ˚C.

1.2) The photometer1.3) The balloonsat must be connected to an inverted

plastic tube will be fixed through the center of the balloonsat. The rope, which is tied to the balloon, is threaded and knotted through the tube.

1.4) Balloonsat must be carried by a latex balloon filled with helium, carrying a parachute deploying on burst, and capable of carrying a net payload of twelve kilograms

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Level 2 (Subsystems Requirements)

derived from level 1 requirements

2.1) The photodiode circuit is connected to the Basic Stamp, where all of the data from the photometer will be stored. 2.2) The Basic Stamp will be preprogrammed to record the data in the proper format.2.3) The camera will be connected to the power source via a switch. The operation of the camera will be controlled by a timing circuit which will be programmed to take photographs at regular intervals of one minute.2.4) The HOBO will consist of two sensors, one recording external temperature of the balloonsat and the other recording internal temperature in ˚C.2.5) The heating unit must operate properly to ensure that the subsystems (excluding the photodiode) will function even though the exterior of the balloonsat will experience temperature extremes of -70 ˚C. Insulation will also be used to keep the BalloonSat above the required 0 ˚C2.6) In order for the balloon to reach its desired altitude of 30 kilometers, each system has to obey the 800 grams weight limit. The balloon will also carry a parachute, to ensure a soft landing velocity of nearly 100 kilometers an hour, and a GPS tracking system to help the team recover the balloonsat.

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3.0 DesignAs a requirement the BalloonSat will be less than 800 grams. At the top of the BalloonSat we have a trapezoid from two sides along the edges through which the photometer is partly sticking out of the satellite, so it will be a challenge to keep it in their optimal position and prevent it from tilting. Positioning of the different subsystems inside the satellite once the insulation has been placed in, will also be a challenge due to the narrow design of the top.

The structure of the satellite will be made of foam core with hot glue connecting sides with aluminum tape. The design of the BalloonSat is based on the proper functioning of the photo diode for the light intensity experiment. The diode has to be placed at an angle forty five degrees with the horizontal. The base part of the satellite will be in a rectangular shape with the dimensions of 25 cm by 10 cm. The height of the cuboidal structure is 15 cm. Above the cuboidal structure we have combined two rectangular sides with two trapezoidal sides. The rectangular sides will be at angle of thirty degrees with the horizontal, and the trapezoids will come up straight, so as to form a roof top type structure with two sides slanting for the housing of the photo diode. The top part after the slants will be a rectangle of 10 cm by 15 cm. The height of the slants will be 10 cm each. The flight string will pass through the center of the top of the satellite and travel straight down through the base. Washers will be placed to keep the BalloonSat from not sliding down the flight string. The reasoning for the slants is to more accurately obtain our data using our photodiode with as little unwanted interference as possible.

The camera will be placed on one of the sides against the wall of the cuboidal structure. The HOBO will be placed caddy corner of the camera. The HOBO sensor will be sticking out of the adjacent wall. The heater will be placed on the base in the middle of the cuboid, as to spread the heat all around the structure to keep all subsystems functioning correctly. The BASIC stamp will be placed opposite of the camera on the other wall of the cuboid. The cold fingers for the photometers will be sticking out of the rectangular top. The condensation packs will be spread out throughout the structure as to keep all subsystems from experiencing condensation.

To keep the BalloonSat above the required temperature of 0 ˚C, insulation will be placed on the inside of the structural walls to maintain a warm temperature for all the equipment inside. Along with the heater placed in the payload, the insulation will further the warmth of all the experiments.

Each subsystem will have an isolated power source, so that if any one experiment fails, the others will go on uninterrupted.

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3.1 Parts-Low dark current silicon photodiode-OPA129 Integrator-OPA27 op amp voltage follower-1000 pF Panasonic metalized polypropylene film capacitor-DIP-packaged reed relay-LM335 temperature detection circuit-4.1 inch PVC pipe with a diameter of 1.5-1.25 inch-1 x 1/18 aluminum bar-Plano-convex lens of 30mm diameter and 25mm focal length-HOBO, BASIC Stamp-Digital Camera with timing circuit-Foam Core-Condensation Gel Packets-Insulation

3.2 Drawings

-A model of the photometer unit (above) and a diagram of the circuit used to connect the photodiode to the BASIC stamp (right).

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3.3 Functional Block Diagram

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Power Switch Heater

Timing Circuit CameraPower Switch

HOBO External Temperature

Power Source Power Switch Photo Diode

BASIC Stamp for data storage

Power 12 V

Power3 9V

Photometer Temperature


3.4 Final Parts List

These parts have been provided by Colorado Space Grant Consortium through the aid of Dr. Fesen and Dr. York Brown

Items were purchases from Home Depot, Batteries plus, and Parallax-Low dark current silicon photodiode-OPA129 Integrator-OPA27 op amp voltage follower-1000 pF Panasonic metalized polypropylene film capacitor-DIP-packaged reed relay-LM335 temperature detection circuit-4.1 inch PVC pipe with a diameter of 1.25 inches-1 x 1/18 aluminum bar-Plano-convex lens of 30mm diameter and 25mm focal length-HOBO, BASIC Stamp-Red Light Filter-Digital Camera with timing circuit-Foam Core-Silicon Condensation Packets-Insulation-Aluminum Tape-Thermal Blanket

From team GONS

4.0 Management

4.1 Organizational Chart

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Team McLovin

Ryan & Tyler Deniz & Jay

Gavin

Photometer Project Managers

Gaurav

Testing manager Rescheduled dates & plan

Injury prevention, safety management BASIC stamp integration

Hardware manager

Photometer circuit construction

HOBO and final structure

Prototype Construction

Data recovery and interpretation

Design for craft dimensions

Launch and Satellite Recovery

Graphical design and analysis

Construction (prototype)

Insulation and protection of vitals

Mass and Cost budget

Tyler- balloon sat launcher

Photometer CircuitPower Source


4.2 Schedule

September 16 First RFP Meeting19 Discuss RFP and Presentation Finalized20 RFP Due27 Team meeting30 DDREV A workOctober 2 DDREV A work3 DDREV A work and completion4 DDREV A and presentation due7 Final Hardware and concept decision9 Team meeting10 DDREV B work11 Order hardware in class14 DDREV B completion16 DDREV B due17 Begin building of prototypes21 Stair tests 1&2, Whip tests 1&223 Review Previous tests, begin final build24 Begin integration of inner components 28 Weigh Satellite, cooler test 130 Cooler test 2, DDREV C work31 Final Tests, DDREV C work, acquire spare partsNovember 4 Test review and Final structure changes7 Compile all launch info and documents; Prep for DDREV C presentation8 In-class Launch readiness review9 DDREV C due, final weigh-in10 Launch Date11 Debriefing meeting, Transfer and analyze recovered data13 Data analysis continued14 DDREV D work15 Finish DDREV D work, begin satellite repair25 Prepare final presentation27 Finish Final presentation, Complete repairs28 Practice DDREV D Presentation29 DDREV D DueDecember 2 Prepare for Final Presentation4 Final Presentation

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Launch Day

5 AM- Leave Boulder, CO

6:30-7:30 AM- Arrive at Windsor, CO Perform Final Systems Checks, Check batteries and replace if necessary Check structural integrity of satellite Clean all lenses Check camera and photometer

7:30 AM- Power up all systems and prepare for flight Go For Launch

7:30 onwards- Trace and Recover Satellite

Post Recovery- Recover satellite Check for any damage to equipment and structure Check all components, data equipment drives

5.0 Budget

5.1 Mass

Item # of Items

Individual Mass (grams)

Structure 1 365HOBO Data Logger 1 35Photometer Unit w/ BASIC 1 94Cold Finger 1 45Red Filter 1 18PVC Pipe 1 66Heating Unit 1 172Digital Camera w/ Timing Circuit 1 225Battery packs 2 5Condensation Gel Packs 4 4Plexiglas 1 17Washers 2 8Piping 1 12Total: 1066 grams

5.2 Money

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Item # of Items

Individual Item Cost ($)

Structure 1 -HOBO Data Logger 1 -Photometer 1 -Heating Unit 1 -Batteries 9V (Heater) 3 -Digital Camera 1 -Timing Circuit 1 -Battery packs 1 -Condensation Gel Packs 4 -Batteries 12 V (Timer) 1 -BASIC Stamp 1 $54.95Home Depot Parts (PVP pipe, laser level, screws, nuts, ruler, Plexiglas, Plexiglas cutter, black spray paint)

$57.00

Red Filter 1 $15.0012 V Battery packs 4 $20.00Total Cost $146.95

6.0 Test Plan and Results

StructuralStair testWhip test Drop test

Subsystems testCooler/ heaterLight/ photodiode calibrationElectrical

HOBOBASIC stampCamera and timing circuitHeater Mission Sim test

In order for our group to have a successful flight and collect substantial data, several tests will need to be performed on both our satellite structure and its inner components. Our group established a detailed day-by-day test schedule to ensure a successful mission. Most importantly, our group needs to test our photodiode because our data will not only reflect our success as a

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group but also will provide data for the further studies of Dr. Brown and Dr. Fesen. Our group aims to have complete confidence in both our structural and subsystems designs. With that in mind, our group will conduct multiple tests using different conditions. From there our group will utilize this information and apply that to out separate designs for best performance. The way that the group will determine which tests were more successful than others will be by means of video photography. With that, the data can be analyzed and then properly utilized.

6.0.1 Stair Test The stair test will be implemented to test the structure of the BallonSat. If the parachute of the balloon fails, the payload needs to survive a harsh landing, which is what the stair test is designed to do.

6.0.2 Whip Test To simulate the flight the BalloonSat will experience once the balloon pops at its maximum altitude. By attaching a cord to the satellite it will be spun around to simulate flight.

6.0.3 Drop Test Incase the parachute fails to deploy, the satellite will be put to very high velocities, so the payload will be dropped from a height of twenty meters to simulate the landing force it could experience.

6.0.4 Cooler Test The payload will experience extreme cold temperatures during flight; by making sure all the experiments function properly, the BalloonSat will be placed in a cooler of dry ice for three hours to experience how long it will be in flight in these extreme temperatures.

6.0. 5 Photometer Testing and CalibrationThe photodiode must first be calibrated to record accurate data. The current plan involves exposing the photodiode to a know wavelength (430nm- 450nm) in a completely dark room to learn the variation constant. This can most easily be done with a laser pointer of known frequency. Testing on the photometer will mostly involve the circuit and basic stamp functioning compatibly together.

The test will be both preformed in a dark room, and in a more practical environment (outdoors)

6.1 Testing Results

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6.1.1 Stair TestTwo sets of this test were performed on the multilayer stairs of the DLC. One round of

testing was done on a prototype with no inner mass, while another was performed using a prototype with a mass of 650 g. Two rounds of this test were performed on each of the two masses. While the prototype of lesser mass, when pitched down the two flights of stairs, sustained almost no damage aside from a

few corner dents, the greater mass prototype sustained a few larger dents when pitched down the stairs. However, structural integrity was not compromised and the inner components took no damage. We gathered from this test that, as mass increases, so does susceptibility to damage. Both prototypes passed the stair test.

6.1.2 Whip TestThis test was performed by four of our six team members at 20 swings per person. A string of approximately two meters in length was strung through the center tubing of our satellite structure with a metal washer on the bottom end to keep the structure on the string. The satellite easily withstood the whipping forces endured in this test. The structure was whipped around at multiple angles in order to simulate the in flight g-forces that may be experienced. The inner components of the satellite will need to be secured more than they were in the test even though no serious damage occurred to the components during the test. The whip test was passed by the structure.

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6.1.3 Drop TestThis test was performed from the bridge between the ITLL and the DLC with two repetitions onto both grass and cement. It was performed using a prototype of similar mass to our final product. Several items of different levels of frailties were placed inside to see how the structure would protect them, such as a working circuit with flashing LEDs and a box of nails. Different methods were also used for placing Plexiglas in two different holes to see which method of placement would be more stable. This is the method we will use for the Plexiglas sheet in front of our camera. The cement landings caused denting on a few of the corners and edges from impact. The grass landings also caused minor denting; however, nothing like the cement landings. The structure remained intact despite the rough landings and dents it received. It also kept the inner components in one piece and operating in the case of the circuit, however more restraint of the components is needed. The best method of placing Plexiglas (placing a larger section on the inside of the structure over a smaller hole instead of placing a piece of equal size to the hole flush with the structure wall) was also determined. A larger piece of Plexiglas over a smaller structure hole was much more stable and the glass stayed attached to the structure longer when this method was compared to the other. The structure passed the multiple drop tests.

6.1.4 Flammability TestThe flammability test was performed to see if the heating circuit overheated if it caused the thermal blanket inside and the insulation to catch on fire. During the testing both did catch on fire so it is necessary that we add a piece of foam core under the heating circuit to prevent this from happening during flight. (Though it was not totally necessary, we felt that it may have some impact on our system.)

6.1.5 Conductivity TestThis test was designed to see if by placing the timing circuit on the thermal blanket would cause shortages with the circuit. We put the timing circuit to take a picture every 50 seconds, and then placed it on the thermal blanket. When it was turned on the circuit started to short out and caused it to take pictures at random intervals and ended up not working. To prevent this from happening we placed a piece of foam core under the timing circuit in the inside of the BalloonSat and it passed the test, it does not start to short out.

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6.1.6 Photometer TestCircuit Test-With the help of Tim May we were able to successfully complete the photometer circuit and although we were unable to finish the BASIC Stamp programming in time to be able to test the circuit with the program. However, we did successfully manage to test the circuit isolated from the BASIC Stamp and observed that our photo voltage using which we will calculate the photo current did rise at the desired rate depending upon the light intensity in the room. BASIC Stamp Program-We were unable to make a successful program despite several attempts and help from professionals. We are still trying to get it done before we turn the satellite in and hopefully if the program is completed we will be able to calibrate our photo diode as well. Without the data from the BASIC Stamp we cannot do the calibration and if necessary we might be forced to do calibration once we have recovered the satellite after launch, which is a feasible option according to Team Ramrod and Tim May.

6.1.7 Camera TestingOur camera will be taking pictures during flight and for it to still be completely inside, we placed a piece of Plexiglas over the inside wall for the camera to look out of. To make sure the camera flash does not highly distort the pictures, we tested the camera with pictures with and without Plexiglas over the lens. From our results with a very clean piece of Plexiglas the images are only slightly distorted; they are not as sharp with the Plexiglas over it. However, this test proves to the team that the Plexiglas does work and it will allow the camera to be covered to stay warm inside.

6.1.8 Cooler TestThis test was designed to see if the functioning parts of the subsystems will work in extreme cold temperatures like the upper atmosphere has. We put in over eleven pounds of dry ice in a cooler and turned on all the subsystems for about three hours. The heating circuit ended up having bad batteries and died, but the overall inside temperature still remained above the required 0°C even without a heating circuit. The BalloonSat passed this test because if stayed above the required temperature and with a working heater it will stay even warmer than without a heater.

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-Cooler Test #1Due to an error in test preparation the heater did not run for the duration of this test. However, from this test we learned that our subsystems were still able to function with just the prior heat of the room remaining in the satellite and no other heat introduced. The subsystems operated for the duration of the test, even without the heater.

-Cooler Test #2This test made use of a working heater, though it failed midway through the test. However, temperature within our satellite stayed well above freezing for the duration of the test, showing an efficient and working use of insulation. All subsystems ran for the length of the test.

6.1.9 HOBO TestingThe HOBO testing is designed to see if the HOBO can perform on the delay start feature. We delayed started the HOBO before one a cooler test, and the HOBO properly turned on at the exact time we programmed it in for. Also, the HOBO testing was successful in measuring internal and external temperatures and the humidity. All of the tests were successful and the HOBO is properly functioning.

6.1.10 Mission Simulation TestThe mission simulation test was preformed in the cooler for an elapsed time of approximately three hours, which was thought to be the time of our flight. After the first test our sat failed, but during later tests once batteries and the circuitry was re-wired the mission was deemed ready to fly.

7.0 Expected Results

When we graph the voltage output from the photometer as a function of time it takes to charge the capacitor each time it should be a linear function. We expect the photocurrent that we calculate using the collected data from the BASIC Stamp should be equivalent to the photocurrent we calculated during calibration of the photodiode. This photocurrent should be proportional to the luminosity (sky brightness) at different altitudes.

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8.0 Launch and Recovery

8.1 Plan for Launch and Recovery

The group will meet in the quad on November 10, 2007 at 5:00 A.M. and leave to the launch site and meet up with the rest of the teams.Jason Hohl will travel with Professor Koehler and the rest of the team will be riding in Ryan Quakenbush’s car.We will be traveling to Windsor, CO for launching. Take I-25 to exit 262, head east on the exit and travel 1.3 miles to County Road 3, and the launch site will be 200 meters down the road.We will be arriving around 6:30 A.M. eat breakfast, and at 7:00 A.M. get ready for launch. Turn on all switches and make sure all parts are working correctly, and any final things done such as re taping sides.Launch will happen at 7:30 AM with Tyler Drake being the person who holds our satellite for the launch.After launch we will head back to the car and chase the satellite at its expected landing point. Gavin Kutil will travel in the car with the GPS systems and keep everyone else informed back in Ryan’s car about the balloon.

Each member of the group will dress properly to stay warm since we will be outside in the early hours of the day as it will be cold. Each team member will also bring a lunch to eat on the chase.

8.2 Account of Launch and Recovery

Team McLovin woke and met at 4:00 A.M. to prepare for the upcoming events of the day. Using the team member Ryan’s car as transportation we all got in, and embarked to the launch location. Fifteen minutes into the trip we received a phone call from one of our teammates telling us that due to illness he would not be able accompany the group. Once we reached our destination we walked around the launch site and got a feel for the operation. After being fed bagels and coffee each team was on standby with one team member being informed on launch procedure. Also, one member was in charge of the safety of the GPS payload during launch. Before we knew it our Balloonsat, along with all the other teams, was in the air drifting away as our heads remained tilted back.

After everyone took in the event of the launch, a couple of people from each team piled into two SUVs equipped with GPS tracking devices and the location of command. Everyone else got into their respected vehicles and followed one of the SUVs. We pursued our payloads and eventually surpassed them. The group stopped in a parking lot for fifteen to twenty minutes to wait for the balloon to catch up with us. Soon enough we continued our quest to the hypothesized landing site. After another similar stop to the one previous we received word that the balloon had popped we continued our pursuit to the final stop. With the payloads about forty yards from the road we were traveling on,

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everyone walked excitedly to their satellite. With the satellites in hand and pictures taken the class finished off the day with some champagne and awesome high fives. The drive back to Boulder gave us a chance to view the pictures from the flight and recount the earlier events of the day.

9.0Results and Analysis

There seems to have been an error in programming the HOBO starting time. Even though the HOBO was programmed to start at 7:20 A.M., it began recording data at 8:20 A.M. This indicates that the HOBO started recording data when the satellite was at an altitude of approximately 15 kilometers, where the temperatures would have been far below freezing. Hence the data seen in the graph is actually the data starting at approximately 15 kilometers. Around 11:20 A.M. the temperature graphs rise back to ground level temperature. The sudden temperature drop seen on the graph between 10:10 A.M. and 10:45 A.M. is when the heater failed and internal temperatures began to drop. The gradual temperature rise following that is when the satellite descends back to the earth and to warmer temperatures.

The heating system failed during flight because we were unable to fly with lithium batteries. We were not able to find stores that carried lithium batteries with the voltage we needed at a short notice because Space Grant had given out all the flight batteries before we could get ours. We were promised batteries for flight and we never got the batteries. This was the only reason why our heating system failed because we improper batteries that could not last for the flight time.

Our HP Digital camera performed perfectly on the flight until a short in its circuitry caused it to cease functioning at about 10 kilometers. Our images were clear and having

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taped off the flash prior to launch, no flash interfered with the Plexiglas. The only problem with two of our photographs was when we were facing the sun; it glared off the Plexiglas and created a large bright spot, obscuring the photograph.

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The data we retrieved from our photodiode was not what we had expected. The photodiode unit worked perfectly; it measured light intensity and recorded it onto the BASIC stamp as a function of time. However, the light was so intense for the level of capacitor we were working with that the capacitor was literally flooded with light. Our program was to take up to 600 readings of light intensity with each reading being the time it took to charge the capacitor to 1.4 volts. The intensity level of the light in the early morning sky was too bright for the equipment with which it was measured and all 600 readings were taken within a timeframe of 60 seconds. When the BASIC Stamp data was recovered and analyzed, we saw this occurrence in the data in that the total count, or the count of time it took to charge the capacitor, was equal to one 600 times. One is the base level reading, or smallest reading of time that was measured and was set to be 0.1 seconds, which tells that if the count was 1 for 600 readings, the total time it took to get all readings was 600*.1sec= 60 seconds.

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10.0 Ready for Flight

There was no structural failure or damage during the flight. None of the subsystems themselves failed, but total system failure occurred after 35 minutes of flight time. This was mainly due to the fact that the lithium ion batteries that were to be installed directly before flight were unavailable for use; regular alkali batteries had to be used and were inadequate for flight needs. Replacement lithium batteries will be installed prior to a second launch. In regard to our provided HP digital camera, there was evidence of a short in the camera circuitry that may have resulted in camera failure after approximately 35 minutes. The short, which had been an issue before launch, was thought to have been corrected but this problem may have still occurred. We know that the camera batteries were not the cause of this issue; we checked the batteries in a different appliance that used similar power to the camera and the appliance worked perfectly, proving the batteries were not the source of the problem. The main capacitor’s capacitance was insufficient to handle the photocurrent produced by the light intensity of the surrounding sky. The brightness of the sky charged the photodiode and filled the capacitor too rapidly to get the readings we desired. In order to compensate, a larger capacitor must be used to handle the bright intensity of the sky. A time pause should also be included in the BASIC stamp program to create a gap between consecutive readings. All aforementioned problems have been corrected and the BalloonSat is ready for a second flight. In preparation for this flight, the satellite should be stored at room temperature in a space with low humidity. All switches should be properly taped down in the off position to ensure that none of the batteries are drained before the flight. This is especially true for the photodiode switch which, if turned on and exposed to a constant light source, will cause significant wear and tear on the photodiode itself and cause it to be unreliable for a second flight. The BASIC stamp memory will also be filled entirely before the flight takes place if this were to occur. The satellite cannot be sealed using hot glue and aluminum tape until the date and time of launch is known so that the HOBO can be manually set. The rest of the satellite can be activated on the day of launch by manually turning all the switches to on. If the satellite is to be launched after a period of time greater than six months, the batteries may need to be replaced before a second flight occurs even though new batteries have been installed to ensure maximum performance.

11.0 Conclusion and Lessons Learned

Team McLovin has learned many aspects of what it is like to propose, build, test, and launch a satellite. Throughout the semester, we learned how to transcend high stress situations. For example, we were facing mission failure on multiple occasions, but with hard work and dedication to our mission we completed our final design and insured that all components were working properly before the deadline. Furthermore, with our other challenging classes, we were put under high stress to complete all the assignments for all the classes. Late nights were spent working on this project because we wanted the team to achieve success and help the studies of the professors we were helping to research. Additionally, we learned the values of a good team and what it takes to be successful. It is not always good to rely fully on other members to complete something themselves, but when all the members had equal input on each component, the team ended up being very

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successful. We did not want to put too much on one individual because then one person would be over stressed therefore not successful. We felt working all as a team was the best way to be victorious; however, each team member had certain areas of expertise to help the greater good of the team.

Another lesson we learned was to not wait on deadlines. At first we procrastinated and waited till the night before or a few nights before design documents or other small details were due. However, as time went on we learned to not wait and started all tasks earlier so we would not create as much stress for the whole group. We also learned that we needed to explore all the details of all the experiments first so we knew what we were getting into. An example is of making a program for the BASIC Stamp. We did not realize till a week an half before launch a program needed to be written and we created a high stress environment that could have easily been avoided if we looked further into all the details.

If we had a chance to retake this class and start over we would have done the process a little bit differently. First and foremost, just like a lesson we learned, we would have not procrastinated. It created a lot of unwanted and unneeded stress because we did not think things would take as long as they did. Furthermore, if we took the class again, we would have chosen an experiment that was more suitable for us just being freshman engineers. We did not have programming experience, and the experiment we chose needed for us to write an entire program and that created a multitude of problems along the way.

12.0 Message to Next Semester

Procrastination is the worst thing that you can do during Gateway to Space. If you want mission success, you have to work hard on the project right off the bat. We know that you have probably read this 10 times over in every other report, but it is true and we cannot emphasize the point that you HAVE to bust tail. Even if it seems that you do not know any direction that you wish to pursue, do not just call it a night. There is always something to do and the earlier you get it done the better off you will be. Even if most of the work is done, prelaunch week is still chaotic and filled with preparations and last minute kinks to work out. The more work that is done before this week, the less stress you will have (and believe us, there will be at least a bit of stress during this time).

This class is more than a normal class. It is a preparation for the rest of your life in a sense that it teaches you values necessary for success: time management, working well with others, speech skills, and work habits necessary for post-college life no matter what you pursue (aerospace or not).

24 Team McLovin

Documents

G-Force, Intensity, and the Power…of Love€¦ · Web viewThe light intensity experiment will be using one light sensitive photo diode placed in the upper corner of the cube at