High Altitude Balloon Project

Transcription

1 High Altitude Balloon Project March 11, 2006 Team: Michael Corbett John Holtkamp Jessica Williams Sean Stevens Brian Wirick Advisors: Dr. Mitch Wolff Dr. Joseph Slater Dr. Ruby Mawasha Dr. Zhiqiang Wu ME Engineering Design Wright State University Dayton, OH

2 Abstract The goals of this project were to design and build a payload to be attached to a weather balloon that would reach an altitude of 100,000 feet and return safely to earth. The payload contained both experiments and tracking equipment such as a GPS (Global Positioning System) receiver and amateur (HAM) radio. The payload was first launched to test the communication and tracking equipment and to define the launch procedures. The remaining launches were to contain the experiments and improved command module that implemented redundant tracking systems. Experiments that were performed included a solar cell study at high altitudes and altitude profiling of temperature, pressure, and humidity. This project used a collaboration of mechanical and electrical engineers to ensure that all components of the project were designed and working properly. The electrical engineers focused on a timer circuit for the camera, directional and omni-directional antennas, and the solar cell experiment. The mechanical engineers focused on designing the payload to withstand extreme conditions, creating a weather balloon filling mechanism, predicting the flight path of the balloon, developing the balloon tracking method, integrating all systems, and designing other experiments. This project established the high altitude balloon program at Wright State University. The experiments performed were significant for a variety of reasons. Very little testing has been done on solar cells at high altitudes and this project helped increase the knowledge base. Determining the effects of low temperature, pressure, and humidity on the electronics can also aid in the development of more robust systems. 2

3 Introduction Weather balloons have been used for many years by meteorologists to study weather patterns in the upper atmosphere. Recently there has been increasing interest in other studies that could be performed using weather balloons in near space environment. The exact definition varies, but near space is often considered the area of the earth s atmosphere between approximately 100,000 and 200,000 feet 1. Universities and other scientific institutes, such as University of Montana and NASA Glenn Explorer Post, Cleveland, OH, have been developing programs that build experimental payloads so that they can analyze the data gathered after a successful launch. The goal of this senior design project was to develop a ballooning program for Wright State University. There are several areas of interest in high altitude balloon experiments. These include radiation effects on solar cells, wireless communication, guidance, and detailed maps of atmospheric conditions in relation to altitude. This wide span of information could be used in many areas such as for military aircraft and for natural disaster rescue teams. High bandwidth wireless communication between the ground and the balloon, as well as between multiple balloons could be used to design communication methods and systems between high altitude unmanned air vehicles (UAV). There is also hope that balloons could be used in natural disaster situations (for example, the aftermath of hurricane Katrina) as temporary communication towers for cell phones. Balloon launches currently are at the mercy of the speed and direction of the jet stream winds. Because of the uncontrollable nature of the winds, balloon launches have uncertainty in the landing location of the payload. A guidance system would be able to direct the payload to land in an unpopulated area and away from any bodies of water. If 3

4 this could be implemented, then retrieval time for the payload would be greatly reduced, the chance of recovery would be significantly higher, and the distance that the payload travels would no longer be determined solely by the high altitude winds. In direct correlation with a guidance system, a method to extend flight time would also lend itself useful to data collection and as a temporary communication hub. One possible method to guide the payload is to maneuver the balloon in and out of different wind currents, blowing it one direction first and then in another direction. This could be achieved through the use of ballast released at proper times, and by bleeding helium out of the balloon at designated altitudes. Guiding the balloon in this manner could gain additional hours of flight time to collect experimental data. Unfortunately, adding a system with ballasts could cause the payload to weigh much more than the Federal Aviation Administration (FAA) twelve pound maximum weight regulation. Therefore, this method cannot be tested while staying with this type of balloon payload. Solar cell research at high altitudes would provide valuable information as well. Knowing how solar cells perform in the near space environment will allow companies to modify their products to be suitable for these extreme conditions. If solar cells can be designed to perform well with the increase of radiation at around sixty to seventy thousand feet, they may be used as an auxiliary power source for high altitude military aircraft. Solar cells may also be a potential source of power for balloon payloads. This would remove the need to have heavy batteries powering all equipment and provide more room for experiments. The experiments to obtain temperature, humidity, and pressure data at different altitudes could help to bring about a more up to date temperature, humidity, and pressure 4

5 profile. Research indicates that it has been nearly 50 years 2 since data has been gathered for this type of study and it is unknown whether the data is accurate for all seasons of the year. If future groups could launch a payload at different times throughout the year, accurate plots could be made for altitudes up to 100,000 feet for the entire year. With this information, companies designing aeronautical systems would be able to account for specific atmospheric conditions at various altitudes during any of the seasons to develop products that are more robust. Design Problem and Approach There were multiple tasks that needed to be completed to make the project a success. The first and biggest task was designing a command module that would withstand extreme environmental conditions and transmit GPS coordinates to aid the team in recovering the payload once it had been launched. Other tasks included designing a balloon filling mechanism, choosing how to connect the payload components together, deciding which balloons, gas, and parachutes to use, constructing a gas tank transport crate, creating pre-launch and launch procedures, and designing initial experiments to be performed. The first steps taken in the project were to assemble the team and brainstorm on the approaches and experiments to be performed. Some of the experiments proposed for the project were solar cell studies of voltage and current at high altitudes, guiding the payload to land in a desired location, achieving high bandwidth communication with the ground, taking temperature, pressure, and humidity measurements during flight, and taking pictures from the payload for publicity purposes. A timeline was then set for the 5

6 completion of tasks, and duties were assigned to team members. The breakdown of the initial timeline and responsibilities are shown in Tables 1 and 2 in the Appendix. After more research had been done and progress was slowed due to uncontrollable factors, it was decided that some of the tasks would not be possible to complete in the timeframe allotted. The actual time line of accomplishments and outline of responsibilities are shown in Tables 3 and 4 of the Appendix. Once the group came to a consensus concerning the desired outcomes of the project, research began to determine the best way to proceed. Presently, there are a few colleges such as the University of Cincinnati (UC) 3 and the University of Kentucky 4 which are launching similar high altitude balloons and performing their own experiments. There are also many simpler projects being done by an Explorer Post affiliated with NASA Glenn Research Center 5 and other such institutions. Each group designs and performs experiments and builds off of other groups successes and failures. This communication and sharing of information rather than being in strict competition allows future projects to evolve and to be more successful. For instance, the Wright State University group visit to UC provided insight into designing and building the payload box, as well as in choosing the core electronics such as the HAM radios. Though many of the parts purchased for the current project were different than the ones used by UC, it was helpful to have an idea of what to look for or avoid. UC was also able to give advice on testing the GPS prior to launch and using a pre-launch checklist. Several of the Wright State team members also witnessed a launch performed by the aforementioned Explorer group. Being present at a launch provided valuable information regarding launch procedures, time frames, and necessary supplies. 6

7 There were a number of design constraints in constructing and launching a payload. The first regulations that needed to be considered were outlined by the Federal Aviation Administration (FAA) Title 49 US Code 14 CFR part The FAA regulations give specific limits on the weight of the payload. The payload could not weigh more than 12 pounds total, with no more than 6 pounds for a single box. This was to ensure that if a plane would hit it, no significant damage would be done to the plane. A light payload was also optimal for experimental purposes because it had a better chance of reaching 100,000 feet since the balloon did not have to be inflated as much to provide the required lift. There were also restrictions on the string used to attach the components to each other and to the balloon. The string had to break under a 50 pound load. If the balloon was to be launched at night, it must have a flashing beacon on it that would be visible from five miles away. Some of the guidelines also specified the launch conditions. The balloon could not be launched over a populated area or if there was more than 50% cloud cover. The operating environment limited the way the payload could be built. The box needed to be lightweight, yet strong enough to take the impact of hitting the ground with the velocity dictated by the parachute. The walls of the payload also needed to be a thermal insulator in order to keep the inside of the box at an acceptable temperature for the electronics. This meant that a process had to be used to make the insulating material stronger and heat transfer involving conduction, convection, and radiation on all sides of the box needed to be considered. The main economic consideration for this project was to stay within a reasonable budget and not to waste monetary resources. The starting budget was $3000, but 7

8 additional money became available later into the project. While this budget might seem gtenerous, many of the parts needed were expensive. The majority of the parts were onetime purchases. Once a payload command box was assembled, it could be reused for future launches if it was recovered. The start-up expenses included: HAM radios for the balloon payload command boxes Foxhunting beacon Mobile HAM radio ground unit Receivers and directional antennas for foxhunting GPS receivers and antennas for the payloads Hand-held GPS receiver for tracking down the balloon Laptop to run predictions, record data, and connect to the HAM radio for APRS (Automatic Position Reporting System) 7 tracking Microprocessors Parachutes and string Cameras and timer circuits Screamer circuit for locating the box after landing Payload box construction materials Each launch required a balloon and sufficient Helium to fill the balloon until it provided enough lift. Each of the experiments had a cost associated with it as well. A detailed break down of the expenses can be seen in Table 5 of the Appendix. 8

9 Calculations and Testing To try to keep all of the components within their optimal operating conditions, the walls of the payload box were made of materials with high thermal resistivity. A thermal analysis was performed on the walls of the box to determine how cold the inside temperatures of the box would be. This was done using the ANSYS finite element analysis package. The procedure to set up the problem to analyze the heat transfer through the walls of the payload can be found in the Appendix. Once a solution was obtained, the temperatures throughout the payload box could be seen. A picture showing how the temperature varies throughout the box has been included in the Appendix (Figure 1 is a view of the inside of the box, Figure 2 is a view of the outside of the box). In order to do the analysis, it was necessary to know certain constants such as the heat transfer coefficient of the different faces of the box and the thermal conductivity of the Styrofoam that made up the walls of the box. The thermal conductivity was calculated using the resistivity of the Styrofoam. This resistivity was labeled on the Styrofoam when it was purchased. To find the thermal conductivity, the thickness of the material was divided by the resistivity. In the case of the payload box, the material was 2 hours* F* inches 0.5 inches thick and the resistivity was 3.3 BTU. In order to solve for the heat transfer coefficients relating to the different surfaces of the payload, Fundamentals of Heat and Mass Transfer 8 was used as a resource. Detailed hand calculations showing how the coefficients were computed can be found in the Appendix. 9

10 Once the values for the heat transfer coefficients and the thermal conductivity were determined, they could be used in the analysis in ANSYS. All of the faces on the inside and outside of the box had heat transfer coefficients set for them. The temperature on the outside of the box was set at -70 C, which was the lowest temperature the payload was expected to experience. The pictures seen in the Appendix (Figures 1 and 2) show only 1/8 of the entire box. It was possible to analyze the entire box using just this portion because the box was symmetric about three planes. All of the thin edges, where the rest of the box would be attached to the analyzed portion, had the thermal gradient set to zero. This boundary condition tells the program that the portion of the box that was drawn was a piece of a whole, symmetric object. Once the analysis was completed, the different temperatures the inside faces of the box reached could be seen. The center of each face on the payload box had the warmest temperature on the surface of the box and the corner had the coolest temperature on the surface. Looking at the colored bar along the bottom of the page, the correlation between temperatures and color could be seen. This analysis helped the team to see how effective the walls of the payload box would be in keeping the electronics from reaching temperatures below their operating ranges. Calculations were also performed to determine the size of the parachute that was needed to carry a payload of 12 pounds to the ground with a maximum landing speed of 15 feet per second. The volume and type of gas to be used in the balloon to provide the amount of lift necessary to carry the payload was determined as well. Equations derived 10

11 in Fluid Dynamics were used to perform these calculations. The basic equations used were: Ideal Gas Law: P = mrt Buoyancy: F B = ρ g air balloon Drag Coefficient: C D = F D 1 ρ V 2 2 A In the above equations, P is the pressure, is the volume, m is the mass, R is the gas constant, T is the temperature, F B B is the buoyancy force, ρ is the density, g is the acceleration due to gravity, C D is the drag coefficient, F D is the drag force, V is the velocity, and A is the area. Detailed calculations can be found in the Appendix. The results showed that a parachute with a 6.35 foot diameter was needed. The two gases that were compared were helium and hydrogen. The calculations showed that less hydrogen would be needed to create the desired lift and would be less expensive. To create the 3 3 same amount of lift, ft of helium would be needed or ft of hydrogen. For safety reasons, helium was selected for use in the balloons despite the lower cost of hydrogen. As mentioned previously, the temperature inside the payload box needed to be maintained at a moderate level in order to ensure the electronic equipment could function properly. The components of the payload were tested in a freezer to ensure that they could withstand the expected temperatures outside of the box at 100,000 feet which could reportedly 2 range from 70 to 100 degrees Celsius (shade side and sun side of the box, respectively). Although temperatures inside the payload were not expected to reach these extreme temperatures, components were chosen that would perform the best in a broad 11

12 range of temperatures. For the first payload constructed, different types of batteries were tested with some of the components in a freezer that maintained a temperature of -13 C. The types of batteries tested were Nickel-Metal Hydride, Alkaline, and Nickel Cadmium. The batteries were each placed in the freezer for 2.5 hours, which is the expected flight time of the payload during a launch. Voltages were tested every 15 minutes to determine the performance of the battery. At the end of the tests, it was determined that Nickel- Metal Hydride performed the best and would be used to power the electronics of the payload. Tabulated results of these tests can be seen in Table 6 of the Appendix. When constructing the second payload, component and system level tests were performed using dry ice. Dry ice is able to maintain a temperature of C. The air surrounding the dry ice in a cooler was measured to be an average of -45 C. In the tests with the dry ice, in addition to testing the robustness of the payload components, lithium ion 9-V batteries were tested in comparison to alkaline 9-V batteries over the duration of approximately three hours. At the end of the three hours, the voltages of the alkaline and lithium ion batteries exposed directly to the air in the cooler showed that the lithium ion batteries performed significantly better in extreme cold. The lithium ion batteries initially read 8.9 V, and after 3 hours dropped down to 7.8 V. The alkaline batteries initially read 9.2 V, and after 3 hours dropped down to less than 3 V. First Launch For the initial launch, some of the tasks that needed to be completed included choosing equipment, designing and constructing the fill valve and the payload box, disassembling a camera and attaching it to a timer circuit, integrating a GPS system with 12

13 a HAM radio, getting a HAM radio license, running pre-launch predictions, and choosing a launch site. The timer circuit was needed on the camera so pictures could be taken at a set interval over a designated time period. The GPS tracking system needed the GPS chip, an antenna to receive information from satellites so that its location could be determined, and a HAM radio to communicate with the ground. A Technician Class (or higher) licensed radio amateur must be present to oversee the use of the HAM radio to transmit GPS data. A fill valve and nozzle needed to be designed and built to be able to get the helium from 244 cubic foot tanks into the weather balloon. Predictions also needed to be made based on wind patterns to determine where the payload would land if it was launched. The first steps taken were to research and purchase equipment for the payload box and equipment for the ground. The payload box was to include a GPS receiver, a transmitter, a temperature measuring device, a camera, and a screamer circuit. A Garmin 15L was chosen for the GPS. The 15L was able to run on low voltages between 3.5 and 5.5 volts. A Kenwood TH-D7A was chosen to be used as the transmitter. This particular HAM radio was picked because it contained a built in TNC (terminal node controller). The TNC is a device that can translate the text strings received from the GPS into a signal that could be transmitted over the national APRS frequency ( MHz). It could also be used for custom packet operation on any allowed frequency in the 2 meter band. A digital camera was selected because more pictures could be stored and all components of the camera would be reusable. To take the pictures, a timer circuit was connected to the camera so a picture would be taken once a minute. An Onset HOBO Temperature Logger 9 was selected to measure the temperature both inside and outside the box. The 13

14 HOBO is a small device that had an internal thermistor and the ability to attach an external thermocouple. It would record the temperatures in pre-selected time intervals to onboard memory. These temperatures could later be extracted with the use of a computer. The screamer circuit was made from a dissected smoke detector and was to be used to help locate the payload once it had landed. The box itself was constructed out of 1.5 inch thick foam insulation that had an R- value of 13. The inside of the box was a 9 inch cube and the Auto Cad design of the walls can be seen in Figures 1 and 2 of the Appendix. The foam was coated with Monokote to increase the structural properties of the walls and the chances of the box surviving impact. The equipment was attached to peg board that formed an X inside the box. The X shape of the peg board was used to increase the structural integrity of the box. A covering was made for the box out of rip-stop nylon (design found in Figure 3 of the Appendix). The covering had D-rings sewn onto it to connect the box to the reducing ring and to more payload boxes together in series. A diagram of the entire balloon assembly can be seen in Figure 4 of the Appendix. Once the payload box was constructed, the entire package was kicked down a flight of stairs. This was to test the durability of the box, components, and connections between components. During the system level testing, problems were encountered with both the HAM radio and the GPS receiver. The HAM radio would occasionally get into a loop where it continually reset itself. Further investigation showed that the voltage going into the radio from the battery would drop to zero and then go back up to 7.8V. The radio would then reset itself. It was discovered that a HAM radio battery would do this if its charge was too close to depletion. Fully recharging the battery would resolve 14

15 the problem. The GPS that was being used, a Garmin 15L, had more severe problems. The first GPS purchased broke in-between tests. It stopped updating the coordinates and output only zeros. The reason why it started malfunctioning was never determined, and the chip was sent back to the manufacturer for replacement. The second GPS chip that was received was plugged in and output a coordinate for a location in Taiwan. Once the GPS was reset with the aid of a computer, it was able to acquire satellites and output a valid longitude, latitude, and altitude. Unfortunately, this GPS chip had a tendency to lock up once power was removed. It was possible to quickly fix the problem by resetting the chip. Once these problems were resolved, the communication system was fully functional. In order to pick a launch site, wind data from the past ten years was analyzed and put through a path prediction program called Balloon Track 10 to make predictions of where the balloon was to land. Depending on the strength of the winds at higher altitudes, the balloon could travel 300 or more miles during its short (approximately hour) flight. The prediction data was used to create a scatter plot of potential landing locations. A single prediction run could be plotted using Google Maps, Yahoo Maps, or a similar Internet based mapping software from within Balloon Track. For multiple points, Xastir 11 was used. Xastir is an open-source APRS mapping and tracking package that is a native Linux application. An X-Windows emulation environment was set up on the laptop dedicated for the balloon project. Xastir was the same program that was used for tracking the balloon during flight. County maps were downloaded from the US Census Bureau 12 for the areas of interest. Example plots showing flight predictions can be found in Figures 5 and 6 of the Appendix. After reviewing a large range of 15

16 predictions, it was decided that a balloon launch would be canceled if the most recent upper air wind forecast contained any five data points with winds above 100 knots, or any one data point with winds above 120 knots. The first launch took place on January 15, The balloon was launched from the municipal airport in Portland, IN. There was less than 5% cloud cover and the surface winds were less than one mile per hour. The temperature outside was -6 C (22 F). The balloon took approximately 45 minutes to fill and used slightly more than one tank of helium (one tank contains 244 cubic feet helium) to achieve the desired lift. An equation from the Montana Space Grant Consortium web site 13 was used to determine the weight of the counter balance. The counterbalance was used to determine when the balloon had enough lift. Empirical data was used to create the following equation: Counter Weight = 1.2*(weight payload + weight parachute + weight balloon) weight balloon Equipment checks were made once all of the batteries and antennas were attached. All components appeared to be working and the tracking program on the laptop computer was receiving coordinates from the GPS. The release of the balloon occurred around 9:10 A.M. The release went smoothly and the balloon went almost straight up. Once the payload was in the air, it had a pendulum motion as it ascended. The first fifteen minutes of the flight went according to plan. The ground unit was able to successfully track the movements of the payload. Once the balloon reached approximately 11,000 feet, the transmissions received stopped updating. Repeater stations throughout Ohio and Indiana were able to receive the packets transmitted by the onboard radio and record them on the Internet. An analysis of these packets showed that for approximately four hours the payload transmitted the same 16

17 coordinates, altitude, and velocity. By using knowledge of which repeaters logged packets and the wind prediction data, the location of the payload was estimated to be east of Cincinnati, OH. While no one has called to say that our first box has been found, there is still hope that someone will contact Wright State. Once the payload is retrieved, the data stored on board will be analyzed. The packets that were received from the GPS before it locked-up were analyzed and compared to the wind data collected from the weather station at Wilmington, OH 14. The data analysis from the first launch can be seen in Figures 7 and 8 of the Appendix. The general trend was that the payload moved slightly slower than the wind speed due to drag. The direction of the flight was not completely with the wind. Both the flight path and the wind direction were toward the southeast, but the correlation was less than expected. This was due to two factors: 1. The GPS data was not updated frequently enough to be very accurate. 2. The payload was swinging below the balloon in a pendulum type motion as the entire system moved in a southeast direction. This would add some error to the direction that the GPS indicated the system was moving. Remaining Launches After the first launch, results were gathered and hypotheses were made regarding the failure of the command box. Some of these ideas included failure of the GPS chip, failure of the HAM radio, broken wire connections, or low voltages and currents supplied by the batteries. Any one of these ideas, or a combination of them, was a possible mode 17

18 of failure. More research was done concerning failures related to GPS systems and it was concluded that the GPS probably locked up. In order to avoid this problem on a future launch, it was decided to include redundant GPS systems in one payload, as well as a constant tone beacon to be utilized in foxhunting as a backup tracking system. A Parallax BASIC Stamp 15 was set up to manage sensor data (temperature, pressure, and humidity), and acquire coordinates from three different GPS chips. This information was transmitted directly to a computer on the ground via HAM radios and was also stored on the BASIC Stamp for analysis when the payload was recovered or in case there would be a problem transmitting it to the ground in real time. The code pertaining to the GPS information and sensor input was written entirely by the group. The BASIC Stamp Syntax and Reference Manual 16 and online help through forums 17 were used as references to speed up the learning process since no member of the group had worked with a BASIC Stamp microprocessor prior to this project. The source code for the programs used to reset the Stamp, read the contents of the memory, and run the main storage and transmission loop are included in the Appendix. A fourth GPS chip was used to transmit to the APRS digipeater network. A digipeater is a digital repeating station that is set up to receive data packets transmitted, and retransmit them to increase the range over which the packet can be received. The APRS packet eventually reaches an IGate (Internet Gateway), which puts the information on the Internet, cataloged by both the call sign of the HAM operator and by the time and date. If the team s receiving antenna became unable to pick up the transmissions because 18

19 the payload was out of range, the information could be accessed later to track the flight path. Foxhunting was implemented as a backup system in case all the GPS chips failed. The system was set up so a beacon would transmit a pattern of tones in Morse code ( / which translates to WSU Balloon ) that could be picked up by the use of directional antennas. With several directional antennas, the group would be able to figure out where the transmitter was located. This is done by having antennas at different locations. Each antenna is slowly swept in an arc while being held horizontally in front of the user. The user listens for when the signal is strongest and gets a general idea as to what direction the transmission is coming from relative to their position. Each person using a directional antenna for foxhunting should have a compass. The compass is to be used with a map to plot the best direction in order to narrow down the search area. It is vital that everyone involved with foxhunting stay in communication because each reported direction is considered simultaneously to determine where the transmitter is. Using all of these methods, it was the hope of the group that the second payload would be found once it was launched. On March 4th, 2006, the group headed to Huntington, Indiana with hopes to have a successful launch and recovery. The balloon was inflated while the rest of the group worked on testing the GPS system with the BASIC Stamp. The previous night the entire system had been tested and worked perfectly, but at the launch site the GPS chips were not functioning correctly. After three and a half hours it was discovered that two of the GPS antennas were too close to each 19

20 other. This close proximity caused them to jam all the GPS receivers in a 200 foot radius. The problem was fixed, but by that time, the batteries in the HAM radios had been used for too long and were judged not to be dependable for an entire flight. Preparations are being made for another launch attempt. On the next launch, the electrical engineers in the group will be implementing a solar cell test which will be monitoring the current and voltage output of solar cells placed on the outside walls of the payload box. Pressure, humidity, and additional temperature readings will be taken as well. Once a launch is successfully performed and the data acquired from the launch is analyzed, the Wright State University Balloon Program will have been successfully established and the members of the group will consider the project a success. Future Goals Though the group has accomplished much in the process of establishing the Wright State University High Altitude Balloon Program, there were many ideas for experiments that were unable to be implemented into a flight because the course only lasted two quarters. The following list contains examples of these experiments: A propulsion system to guide the balloon back toward Wright State University An air release valve to control when and at what altitude the balloon will burst Tests involving wireless communication between two balloons that are launched simultaneously 20

21 An experiment where a small plane, powered by solar cells, with inflatable wings would be launched from the payload Initially the group hoped to implement some, if not all, of these experiments into the project, but it became apparent that this would not be possible due to time constraints. The proposed experiments are projects that can be undertaken by future groups. Starting a High Altitude Ballooning program at Wright State University was a challenging task. Advice was taken from other groups, but there was much the Wright State group had to learn on their own. Now that the Wright State group has started the program, they have been able to share the information gathered through research and system checks to help other groups, such as Cedarville University, start their own programs. Five students and an advisor came to Wright State to get ideas of what a balloon project might entail. The mechanical engineers from the Wright State group spoke to them about Wright State program. Information was given regarding payload construction and communications to prevent them from struggling with the same problems faced in this project. It is the desire of the current group that future Wright State groups will communicate with other local schools to help others and get ideas on how to improve their own program. Organizations such as Central State University and AFIT (Air Force Institute of Technology) have shown interest in the Wright State program. It was intended that one of Wright State s launches would have tests from another organization implemented into Wright State s payload. Unfortunately, this was not able to happen in the time frame of this project. While giving a presentation on the balloon project at DCASS (Dayton- Cincinnati Aerospace Sciences Symposium) on March 8, 2006, AFIT expressed interest 21

22 in testing long range wireless communication in a future launch. There could be some interaction between Wright State and AFIT in the future to perform different system experiments. With a working payload, specific launching procedures and guidelines in place, future groups will be able to start designing more advanced and detailed experiments. It would be in the best interest of future groups to spend the first several weeks going through the process of researching the components being used in the command box and rebuilding the exact payload box and system that the current Wright State group had made. This will increase their understanding of how the system works, and how experiments can be integrated into the current system. It will also give them an understanding of the assembly so more payloads could be constructed if one became damaged or unrecoverable. Conclusion The Wright State Balloon project began with the expectation that it would be a straightforward process to create a program for launching payloads, and within two quarters, complex tests could be integrated into the system to be performed during a flight. It became clear as the first box was being designed and built that the project entailed more development and design aspects than the group had anticipated. After the unfortunate loss of the first payload, it was determined that the complex tests planned for would most likely not make it into one of the current group s launches. Instead, the current group decided to focus on establishing the program and a detailed system in 22

23 which launches could take place with a significantly greater chance of recovering the payload. The failed recovery was analyzed and different modes of failure were suggested. The weak areas in the original design were investigated and improvements were made to the system to create a more robust communications box. Studies were performed on GPS chips and their high failure rate. It was soon realized that a single GPS chip was not reliable enough to depend on it as the only means of locating a payload. The decision was made to implement multiple GPS chips from different manufacturers in the same payload. Also, the group began looking into foxhunting. This way, a failure of any single component would not cause the payload box to be unrecoverable, and future groups would have a better idea of which GPS chips performed the best in high altitude applications. Most of the components in the new payload were integrated with a BASIC Stamp. The BASIC Stamp is a microprocessor that is able to store information from the flight, and could be used for future groups to perform basic algorithms to control their experiments. Learning how to use the Stamp, wiring the circuit, and writing code for it to be integrated with multiple GPS chips and sensors was a time consuming task. This is just a small example of how the work that has been done in the last two quarters has established the program. Despite the fact that not all the experiments that were originally planned could be accomplished in the given timeframe, the work that has been done by the group has been invaluable. The Wright State Balloon group is proud to say they have successfully established the Wright State Balloon Program that can be continued for years to come. 23

24 1 Samson, Victoria. "Space Security." CDI Center for Defense Information. 25 Sept < 2 "U.S. Standard Atmosphere 1976." United States Committee on Extension. 05 Oct < 3 Urbaniak, Matthew. "Getting Started, Overview and Suggestions/Lessons Learned." University of Cincinnati, OH. 28 Sept "Big Blue 3." 30 Apr University of Kentucky. < 5 Schilling, Herb. "Explorers Post BalloonSat." NASA. 29 Sept < 6 "Electronic Code of Federal Regulations." 27 July National Archives and Records Administration. 10 Oct < 5&idno=14>. 7 Automatic Position Reporting System. 24 Sept Oct < 8 Dewitt, David P., and Frank P. Incropera. Fundamentals of Heat Transfer. 5th ed. Hoboken: John Wiley & Sons, Onset. 10 May Oct < 10 Von Glahn, Rick. "Balloon Track for Windows." 10 Dec Edge of Space Sciences. 14 Oct < 11 XASTIR. 1 Nov Oct < 12 "2005 First Edition TIGER/Line Files." 1 Dec U.S. Census Bureau. < 13 Allen, Jacqueline. "Borealis: The Montana Space Grant Consortium High Altitude Balloon Program." Montana Space Grant Consortium. 29 Sept < 14 Oolman, Larry. "Weather." University of Wyoming. < 15 Parallax Oct < 16 Martin, Jeff, Jon Williams, Ken Gracey, Artistides Alvarez, and Stephanie Lindsay. Basic Stamp Syntax and Reference Manual Corbett, Michael W. "Converting a Digital Temperature Reading to ASCII Values." Parallac. 24 Feb Feb <Basic Stamp>. 24

25 Bibliography "10-Bit Analog-to-Digital Converters with Serial Control and 11 Analog Inputs." Texas Instruments < "2005 First Edition TIGER/Line Files." 1 Dec U.S. Census Bureau. < "2 Meters." Wikipedia. 19 Feb < "A12, B12, ans AC12 Reference Manuals." Thales <ftp://ftp.thalesnavigation.com/oem,%20sensor%20&%20adu/a12,%20%20b 12,%20&%20AC12/Reference%20Material/A12%20B12%20AC12%20Referenc e%20manual%20revd.pdf>. "Airport Information." < Allen, Jacqueline. "Borealis: The Montana Space Grant Consortium High Altitude Balloon Program." Montana Space Grant Consortium. 29 Sept < "Ansys Tutorials." FTM Studios. 05 Mar < APRS. 25 Apr Oct < Automatic Position Reporting System. 24 Sept Oct < "Basic Stamp (OWL2) to TLC2543 analog to digital converter." EME Systems. 22 Dec < "Basic Stamp Microcontroller." Parallax. <

26 "Big Blue 3." 30 Apr University of Kentucky. < Carmichael, Ralph. "Properties Of The U.S. Standard Atmosphere 1976." 25 Jan Public Domain Aeronautical Software. 10 Oct < Cengel, Yunas A., and Michael A. Boles. Thermodynamics: An Engineering Approach. 4th ed. New York, New York: The McGraw-Hill Company, Corbett, Michael W. "Converting a Digital Temperature Reading to ASCII Values." Parallac. 24 Feb Feb <Basic Stamp>. Dewitt, David P., and Frank P. Incropera. Fundamentals of Heat Transfer. 5th ed. Hoboken: John Wiley & Sons, "Electronic Code of Federal Regulations." 27 July National Archives and Records Administration. 10 Oct < ode=14: &idno=14>. "EM-401 GPS Engine Board with Active Antenna Product Guide." Global Sat. < Fox, Robert W., Alan T. McDonald, and Philip J. Pritchard. Introduction to Fluid Mechanics. 6th ed. Vol. 2. Hoboken: John Wiley & Sons, "GPS Sensor Boards GPS25-LVC, GPS25-LVS, GPS25-HVS Technical Specifications." Garmin <

27 "HIH " Honeywell < &PN=HIH >. Holtkamp, John C. "Questions about Handheld Ham Radios." Eham.net. 08 Feb Feb <MobileHam>. Holtkamp, John C. "Signal Generator." Eham.net. 15 Feb Feb <FoxHunting>. "Image 20." Chart. The Spcae Science Division at the Naval Research Lab. 05 Oct < "INTRODUCTION TO UPPER ATMOSPHERIC SCIENCE." Naval Research Lab. 05 Oct < Kroo, Ilan. "Standard Atmosphere Computations." 14 Apr Aircraft Aerodynamics and Design Group. 05 Oct < Martin, Jeff, Jon Williams, Ken Gracey, Artistides Alvarez, and Stephanie Lindsay. Basic Stamp Syntax and Reference Manual Monokote Oct < Onset. 10 May Oct < Oolman, Larry. "GFS Maps." University of Wyoming. < Oolman, Larry. "Weather." University of Wyoming. < Parallax Oct <

28 Picone, J. M., D. P. Drob, R. R. Meier, and A. E. Hedin. "NRLMSISE-00: A New Empirical Model of the Atmosphere." 29 Oct Universities Space Research Association. 04 Oct < "Pocket Tracker." Byonics. < Salo, T J. "Minnesota's High-Altitude Amateur Radio Balloon Project." University of Minnesota. < Samson, Victoria. "Space Security." CDI Center for Defense Information. 25 Sept < Schilling, Herb. "Explorers Post BalloonSat." NASA. 29 Sept < "SDX15A4." Honeywell. < 5A4>. "Search Results for KD8CKD." Aprsworld.net. < =yes>. "Sony GXB5210 GPS Reciever Data." 26 Aug Synergy Systems, LLC. < Stanley, Mark. "1976 U.S. Standard Atmosphere." 22 Oct Oct < "TinyTrak3." Byonics. <

29 United Solar Ovonic U.S. General Services Administration. 12 Oct < Urbaniak, Matthew. "Getting Started, Overview and Suggestions/Lessons Learned." University of Cincinnati, OH. 28 Sept "U.S. Standard Atmosphere 1976." United States Committee on Extension. 05 Oct < Von Glahn, Rick. "Balloon Track for Windows." 10 Dec Edge of Space Sciences. 14 Oct < Von Glahn, Rick. "Edge of Space Sciences." 15 Jan < XASTIR. 1 Nov Oct <

30 Appendix

31 Figure 1: ANSYS steady state heat transfer solution. The inside of a 1/8 portion of the box is shown.

32 Figure 2: ANSYS steady state heat transfer solution. The outside of a 1/8 portion of the box is shown.

33 Figure 3: Puzzle piece design of the first payload box. The second payload box was a similar design but the exact dimensions were adjusted due to the different foam thickness.

34 Figure 4: Scale drawings of the first payload box including dimensions. The second payload box was a similar design but the exact dimensions were adjusted due to the different foam thickness.

35 Figure 5: Rip-stop nylon cover for the payload. Dimensions were shown so that the cover could be sewn to exact specifications to provide a snug fit around the box.

36 Balloon Parachute Reducing Ring Payload Box Antenna Figure 6: Diagram (not to scale) of the entire system.

37 Figure 7: Predictions for 10 years of data for the target November launch date +/- 4 days. The launch location was Ft. Wayne, IN. The clustering of landing sites near Lake Erie suggested that the launch site should be moved further south in Indiana.

38 Figure 8: Predictions for the first launch. The launch location is Portland, IN. The wind data is from the morning of the actual launch. Mapped predictions are based on Balloon Track (marked BT ) and a custom-made model (marked M ) analyses.

39 Speed vs Altitude Speed (mph) Wind File GPS Altitude (ft.) Figure 9: Speed reported by the GPS receiver and transmitted to the ground plotted versus altitude. It is compared with the wind speed since the balloon should move approximately with the wind speed. The values are consistently below the wind data due to drag.

40 Direction vs Altitude Direction (degrees) Altitude (ft.) Wind File GPS Figure 10: Heading reported by the GPS receiver and transmitted to the ground versus altitude. It is compared with the wind direction since the balloon should move approximately with the wind. The correlation between the GPS flight path and the wind data path was less than expected, but both suggest the balloon moved roughly toward the southeast.

41 03/06/06 Week 27 03/13/06 Week 28 Fall Quarter Christmas Break Winter Quarter 09/05/05 Week 1 09/12/05 Week 2 09/19/05 Week 3 09/26/05 Week 4 10/03/05 Week 5 10/10/05 Week 6 10/17/05 Week 7 10/24/05 Week 8 10/31/05 Week 9 11/07/05 Week 10 11/14/05 Week 11 11/21/05 Week 12 11/28/05 Week 13 12/05/05 Week 14 12/12/10 Week 15 12/19/05 Week 16 12/26/05 Week 17 01/02/06 Week 18 01/09/06 Week 19 01/16/06 Week 20 01/23/06 Week 21 01/30/06 Week 22 02/06/06 Week 23 02/13/06 Week 24 02/20/06 Week 25 02/27/06 Week 26 Choosing Project Brain Storming Forming Team Landing Predictions 1st launch 11/28/05-11/29/05 2nd launch 02/11/06 3rd launch 03/04/06 Budget for 1st launch Ordering for 1st launch Building Controls Box Camera Timer Data Storage Filling Valve HAM License Thermocouples Solar Cell Experiment Air Release Valve Parachute Deploy Tethered Balloons Alternative Comunications Guidance System/Device Object Launched off Antenna Box Design Pressure/Humidity Readings Thermal Analysis Analysis of Results Table 1: Old Gantt Chart timeline.

42 Original Mike John Jessica Brian Sean Camera Timer x x xx - Primary Data Storage x x x - Secondary Filling Valve x xx Thermocouples xx x x x Solar Cell Experiment x xx xx Air Release Valve x xx Parachute Deploy x xx Tethered Balloons x x x Alternative Communications xx x x Guidance System/Device xx Object Launched off xx Predictions xx x Antenna xx x Box Design xx x Pressure/Humidity Readings x xx Thermal Analysis xx x Table 2: Old responsibilities list.