Pdr Report

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Southern Texas BalloonSatellite Project

Team Lead:Aaron Higginbotham EE Sr. [email protected]

Team Members:

Faculty Advisor: Mentor:Tony Kim Tony KimElectrical Engineering NASA Administrator's

And Computer Science Fellowship [email protected] [email protected]

Frank H. Dotterweich College of EngineeringMSC 192,Texas A&M University-Kingsville

Kingsville, TX-78363

Gabriel Alaniz EE Sr. [email protected] Cantu CE Sr. [email protected]

Charles Easter ME Sr. [email protected]

Alain Gallegos CS Sr. [email protected] Hinojosa CS Sr. [email protected] McConnell EE Sr. [email protected]

Ronald Medlock ME Sr. [email protected] Najera CS Sr. [email protected] Neth EE Sr. [email protected] Patel EE Sr. [email protected]

Baldemar Quintero, Jr. EE Sr. [email protected] Rice ME Sr. [email protected]

Rene Rios EE Sr. [email protected] Saenz CE Sr. [email protected] Saenz EE Sr. [email protected]

Griselda Saldivar CE Sr. [email protected] Salinas EE Sr. [email protected]

Juan Terrazas CE Sr. [email protected] Torres CS Sr. [email protected] Valdez EE Sr. [email protected]

Jaime Vaquera CS Sr. [email protected] Villalobos EE Sr. [email protected]

Yung-Chang Wang EE Sr. [email protected] Williamson CE Sr. [email protected]

Crissy Zarate CS Sr. [email protected]


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Table of Contents

List of Tables and Figures ...............................................................................................31.0 Introduction................................................................................................................4

1.0 Introduction................................................................................................................42.0 Sponsor/ Research Group Identification....................................................................43.0 Collaborative Efforts ..................................................................................................54.0 Team ID/ Members Profile .........................................................................................7

Major............................................................................................................................75.0 Team Patch Design / Description ..............................................................................86.0 Topic Background......................................................................................................97.0 Design Objective .......................................................................................................98.0 Project Requirements and Constraints ....................................................................10

8.1 Need Statement ...................................................................................................108.2 Requirements.......................................................................................................10

9.0 Design Plan/ Methodology.......................................................................................1210.0 Preliminary Design Level.......................................................................................1310.1 Mechanical Engineering.....................................................................................1410.2 Electrical Engineering ........................................................................................20

Power .....................................................................................................................22Termination ............................................................................................................23Sensors ..................................................................................................................24

ATV ........................................................................................................................26Data Systems .........................................................................................................29Packet Radio ..........................................................................................................32Satellite Antennas...................................................................................................33

10.3 Computer Science..............................................................................................36Communication Port ...............................................................................................37Data Flow Loop ......................................................................................................37Database ................................................................................................................38Bring to memory (buffer).........................................................................................38Data In Conversion.................................................................................................38Data Analysis .........................................................................................................38Display....................................................................................................................39Command Log........................................................................................................39Data Out Conversion ..............................................................................................39

10.3 Web Site Development ......................................................................................4010.4 Civil Engineers ...................................................................................................42

11.0 Risk Management..................................................................................................43STRUCTURE AND MATERIAL ANALYSIS AND TESTING: .................................45ELECTRICAL TESTING:........................................................................................46

13.0 Payload Requirements ..........................................................................................4714.0 Projected Launch Day Operations.........................................................................4815.0 Conclusion.............................................................................................................4916.0 Reference / Bibliography .......................................................................................50


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Appendix update............................................................................................................521.1 Schedule ..............................................................................................................521.2 Budget and Expenses ..........................................................................................531.3 Work Breakdown Structure ..................................................................................55


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List of Tables and FiguresTable 4 2 - Members Profile ............................................................................................7Figure 5.1 - Team Patch ..................................................................................................8Figure 10.1. 1 - Total System ........................................................................................15

Figure 10.1. 2 - 3-D View of Satellite .............................................................................16Figure 10.1. 3 - Cross Sectional View of Satellite..........................................................16Figure 10.1. 4 - Top View of Satellite.............................................................................18Figure 10.1. 5 - Front View of Satellite ..........................................................................19Figure 10.2 2 - Satellite Functional Block Diagram........................................................22Figure 10.2 3 - Rechargeable Variable Lithium Battery .................................................23Figure 10.2 4 - Temperature and Pressure Sensor .......................................................24Figure 10.2 5 - GPS Sensor ..........................................................................................25Figure 10.2 6 - 12-Pin Connector ..................................................................................25Figure 10.2 7 - Recommended 12-pin setup .................................................................26Figure 10.2 8 - ATV Transmitter ....................................................................................27

Figure 10.2 9 - Two Input Analog Switching System with Digital Control ......................27Figure 10.2 10 - Two Input Multiplexer ..........................................................................28Figure 10.2 11 Transmitter for 2m Band.....................................................................33Figure 10.2 12 - VHF Receiver for the 70cm Band........................................................33Figure 10.2 13 70cm ATV Little Wheel Antenna.........................................................34Figure 10.2 14 - 2m Dipole Antenna..............................................................................35Figure 10.2 15 - 2m Dipole Antenna..............................................................................35Figure 10.2 16 - Ground Control Design........................................................................35Figure 10.3 1 Ground Station Software Flow Chart ....................................................37Figure 10.3.1.1 Space Hogs Main Page.....................................................................41Figure 10.4.1 CE Work Breakdown Structure................................................................42

Table 11.1 Risk Action Items......................................................................................44Table 11 2 Level of Risk Chart ...................................................................................44


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1.0 Introduction

Space is the frontier of the future, bringing new adventure to a new type of

pioneer. Technology is the gateway to this un-chartered territory and will allow the

senior design class from the University of Texas A&M Kingsville to explore and obtain

a glimpse of space though a balloon-borne high altitude satellite. This balloon satellite

project is a multidisciplinary experiment that will incorporate the use of system

engineering skills as well as a wide variety of technical skills. This project will involve

students from the disciplines of Electrical Engineering, Computer Science, Civil

Engineering and Mechanical Engineering. Within the course of two semesters, the

team will create a balloon satellite equipped with on-board information storage as well

as real time data transmission with video and instrumentation to support a variety of

payloads. The satellite will be a facility that can provide common services to an altitude

of 100,000ft. The data will be relayed to a ground system where the information will be

analyzed, displayed, and used to track and recover the system. This project will enable

students to flex and strengthen their engineering knowledge while giving them the

opportunity to explore space!

2.0 Sponsor/ Research Group IdentificationTony Kim is mentoring the balloon satellite project. Kim is a graduate from the

University of Illinois with a degree in aeronautical and astronautical engineering and a

master's degree in material science from Auburn University. Since 1990, Kim has been

an employee of NASA. He is a project manager at the National Space Science and

Technology Center (NSSTC) in Huntsville, Alabama and has completed projects such


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as the Altus Cumulus Electrification Study (ACES), which enabled researchers to study

thunderstorms through the use of an uninhabited aerial vehicle. Currently, as part of the

NASA Administrator Fellowship Program (NAFP), Kim is conducting the Senior Design

class at Texas A&M University- Kingsville.

3.0 Collaborative Efforts

A large part of the research conducted has been through collaboration with outside

sources, which will continue to be utilized throughout the duration of the project.

Several organizations and individuals that have experience in the area of balloon

satellites have been contacted. Several team members involved in the data

communications section of the project have joined the local HAM radio club to enhance

their knowledge in amateur radio and amateur TV, which will be utilized in the real time

data transmission at such a high altitude. The Edge Of Space Sciences group (EOSS),

which works with students who fly balloons over 100,000 feet in the air, has also been

contacted. The EOSS has been a valuable asset because of the experience in sending

balloons to the edge of space successfully, which is the goal of the project.

On October 14, the team traveled to (NOAA) in Corpus Christi, TX to watch a

weather balloon launch. At this event, the team was able to observe the proper

procedures of handling a balloon during inflating and launch. Safety measurements that

must be taken in order to have a successful launch were observed.

Towards the beginning of the research process, team members engaged in a

teleconference with Ed Myska, Dennis Galleger, and Mark Adrian who are experienced

in the area of balloon satellites. Ed Myska works for the National Space Science


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Technology Center (NSSTC) as a computer information systems support. Amateur

radio (HAM) and amateur video are interest and hobbies of his. Dennis Galleger is a

scientist at NSSTC and studies the spacecrafts electrical environment and the charging

effects on electronics. Mark Adrian is a contractor supporting Dennis Gallegers

research. These three also have experience launching balloons at night to obtain video

of the Leonid meteor shower at a high altitude.


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4.0 Team ID/ Members ProfileThe course name is entitled CSEN 4201: Multi-disciplinary Senior Design. This

course will provide students with engineering experience from the process of project

initiation to project completion, and everything in between.

Faculty AdvisorTony KimOffice #: EC 309Phone: (361) 593-2848FAX: (361) 593-2110Email: [email protected]

Table 4 1 - Members Profile

Members Profile

Name Major Level Role Email

Gabriel Alaniz EE Sr. Satellite [email protected] Cantu CE Sr. Launch [email protected] Easter ME Sr. Structure [email protected] Gallegos CS Sr. Data System [email protected] Higginbotham EE Sr. Satellite [email protected] Hinojosa CS Sr. Satellite [email protected] McConnell EE Sr. Satellite [email protected]

Ronald Medlock ME Sr. Structure [email protected] Najera CS Sr. Data System [email protected] Neth EE Sr. Satellite [email protected] Patel EE Sr. Satellite [email protected] Quintero, Jr. EE Sr. Satellite [email protected] Rice ME Sr. Structure [email protected] Rios EE Sr. Satellite [email protected] Saenz CE Sr. Launch [email protected] Saenz EE Sr. Satellite [email protected] Saldivar CE Sr. Launch [email protected] Salinas EE Sr. Satellite [email protected] Terrazas CE Sr. Launch [email protected] Torres CS Sr. Data System [email protected]

Elena Valdez EE Sr. Satellite [email protected] Vaquera CS Sr. Data System [email protected] Villalobos EE Sr. Satellite [email protected] Wang EE Sr. Satellite [email protected] Williamson CE Sr. Launch [email protected] Zarate CS Sr. Data System [email protected]


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5.0 Team Patch Design / Description

Figure 5.1 - Team Patch

The balloon satellite team has chosen to refer to themselves as the Space Hogs.

The team patch was designed to reflect several features that are relevant to the group.

The patch consists of the outline of a Javelina (hog), which is University of Texas A&M

Kingsville Universitys mascot. To the left of the hog, there is a balloon satellite, which

represents the teams project. The state of Texas drawn on the balloon signifies

University of Texas A&M Kingsvilles geographic location. A shuttle can be seen

soaring across the sky to represent the teams connection with NASA. The shooting

star indicates the goals that the Space Hogs are striving to accomplish!


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6.0 Topic Background

This will be the first time that Texas A&M- Kingsville will develop a balloon-borne

high altitude satellite. The satellite will be capable of carrying payloads designed to

collect various measurements and video to explore the outer edge of the atmosphere at

a minimum altitude of one hundred thousand feet. The role of the supervisor in this

project is minimal. Students are given overall deadlines and are given freedom to make

their own schedules to find time to complete the design. The workload has been

identified using a Work Breakdown Structure, which can be seen in appendix 1.3.

7.0 Design Objective

While in flight, the instruments on board the satellite will take measurements of

temperature, pressure, position, and altitude through the use of GPS and sensors. A

real time video from the satellite will be broadcast, received, and recoded on the

ground. The satellite experiment will also provide data about the effects of radiation on

various equipments, the performance of hardware at extremely high altitudes, and the

efficiency of various insulating materials. This project incorporates aspects from all

disciplines involved. The Electrical Engineering aspect of the project includes designing

the communications and power systems. The Computer Science majors task is

designing the data acquisition, manipulation systems and interfaces for the data

retrieved. The Mechanical and Civil Engineers are concerned with the design of the

physical structure for the satellite and establishing launch capability with a balloon and

parachute. The satellite will have the capability of carrying additional payloads in order


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to give others not involved with the experiment the opportunity to add their payload and

have the ability to also explore the outer edge of the atmosphere through our satellite.

The payload will have to meet certain requirements set by the Space Hogs team.

These requirements will be concerned with the power consumption, data format, size,

and weight of the payload.

8.0 Project Requirements and Constraints

8.1 Need Statement

To become space explorers inexpensively and to fulfill the TAMUK requirement for

senior design for graduation, we will go to the edge of space remotely in real-time to

collect scientific data on a balloon-bourn satellite. During the two semester time period,

the team has a possible budget constraint of $9800-- $4000 of which will be received

from the university, and $5800 can be earned from the TSGC.

8.2 Requirements

I. The balloon shall meet all Federal Aviation Administration (FAA)

requirements.

o The balloon-satellite will be in accordance with FAA size and

weight regulations, which has been designated as a payload of a

maximum of 12.6 pounds.

o The balloon will be equipped with an alternative termination

system.


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II. The balloon-satellite shall meet all Federal Communications Commission

(FCC) requirements, including all provisions concerning amateur radio and

other specifications for unmanned balloon flights.

III. The satellite shall provide provisions for a payload able to send data to the

ground via the satellites, and command able from the ground.

IV. The satellite shall broadcast real-time telemetry, which shall include

temperature, pressure, position and altitude data.

o The balloon will be tracked and recovered by GPS position

information.

o The ground control station (GCS) will display and record all data

from the satellite (video and telemetry) throughout the entire

mission (launch to landing). The GCS antenna/system will receive

signals from all distance ranges up to a 200-mile radius.

V. The launch system (balloon) shall carry the satellite and payload to a

minimum altitude of 100,000 ft.

VI. The satellite shall be reusable.

o The balloon launch system will contain a parachute, which will

reduce the speed of decent as required.

o The ground team will choose a launch site that will guarantee a

land recovery.

VII. The satellite shall be reconfigure-able with a new payload and launched

within one day.


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9.0 Design Plan/ Methodology

The balloon satellite team will use the System Engineering methodology to carry

out this project. This methodology is a cycle of steps that maximizes the final product.

The cycle starts by stating the objective or problem. System requirements are assigned

tohelp make a clear picture of what needs to be done. The requirements are

categorized in two parts: mandatory and preference requirements. The mandatory

requirements are the most basic requirements needed to meet the objective. The

secondary preference requirements are those that the team will complete to enhance

the product output. The team will then define performance and cost measurements for

the project.

The next step in the cycle is testingand validating requirements. This process

ensures that all the requirements that were placed on the project are consistent and can

be accomplished.

In order to integrate this project, the team will conduct design reviews. The

review is a two-step process. The first step is called preliminary design review. This

step contains a model that has been simulated and has passed the requirements list.

The next step contains the prototype that is reformulated from issues raised from the

first review. This is called a critical design review.

The design reviews will let the team know if alternative concepts should be

explored. The team will look into a new design concept if the original concept does not

meet a complete level of satisfaction.

This project has a large scope, and it will be accomplished by completing many

different levels. The team will realizethese tasks by functional decomposition. Tasks


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are to be broken down, which is done by creating a work breakdown structure. The

work breakdown structure is a basic block diagram of the project. This will enable the

team to make theproject easier to handle. The cycle continues with system modeling.

This helps the team look for a better alternative concept to improve the design. This

leads to the system design stage, which will help the team create a product that is

reusable and flexible. The system design will help the team manage anyinterface and

system integration.

The final stage of the cycle is a total system test and documentation of the

project. The total system test is an analysis of the final product in real world conditions.

The documentation is a pool ofdata, design issues, and all other information used in

the project gathered and documented. The system engineering cycle will manage the

project from the start to finish.

10.0 Preliminary Design LevelThe building of the satellite involves many specialized areas. Once the initial

research was completed and the work was identified, the team was able to divide the

design and planning process among the engineering disciplines. The Mechanical

Engineers are designing the structure of the satellite that will be able to withstand any

hardships the payload may encounter during launch, flight, or landing. The electrical

engineers will design the payload that will fit into the structure designed by the

Mechanical Engineers. This payload will contain electrical components that will gather

real time data, which will be transmitted to a ground system. The Computer Science is

developing software that will enable the ground system to analyze and display the data


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that is received by the ground system. The civil engineers will be in charge of ensuring

the satellite is able to have a safe launch and landing. This involves guaranteeing that

all laws and regulations are complied with. The individual disciplines design processes

are described in the following sections:

10.1 Mechanical Engineering

The Mechanical Engineers play an important role in the design and fabrication of

the balloon satellite. Every component that is launched into the atmosphere will be

inspected, tested, and approved by the mechanical team. The main focus is on

structures and environmental needs, such as thermal, moisture, radiation, and forces

from launch to landing.

The structure of the satellite will be a large determining factor for the success of

the project. The structure will be used to enclose the instruments and the electrical

components necessary for the satellite. It will also provide space and weight capability

for a generic payload. The weight and space that will be provided will be determined

after all components are on board.

Careful consideration was taken when deciding how to arrange the components

inside the structure in order to ensure they would be safe from the impact of the ground

and from the force of the parachute, which is estimated to reach up to five times the

force of gravity. (www.nsbf.nasa.go/LDB-Fliaght-Application-fy2003.pdf, pg. 22) It

has been decided that the components will be pressed into self-shaping foam that will

absorb the impact energy as well as keep them from moving during the flight. The


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arrangement of the components inside the structure can be seen in the AutoCad figures

10.1.2 and 10.2.3:

Figure 10.1. 1 - Total System


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Figure 10.1. 2 - 3-D View of Satellite

Figure 10.1. 3 - Cross Sectional View of Satellite

The affect the parachute will have on the structure has been an important aspect

of research. A large force will act on the structure once the parachute is deployed.

During that time, the structure will try to continue accelerating due to the principle of


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inertia. The parachute will resist this acceleration resulting in a force on the structure.

To negate this effect, the parachute and balloon will be attached to the bottom of the

structure by a cord that goes through the middle of the device. This will ensure that the

structure willslow down on a uniform basis and not be pulled apart when the parachute

suddenly slows it.

The design considerations were greatly affected by the environmental conditions

the satellite is predicted to encounter during its flight. As the satellite ascends and

descends, it will feel a substantial temperature change. This change will produce

condensation that could damage sensitive equipment on board. Styrofoam was chosen

as the material for the shell because it is light, a good insulator, and it can repel

condensation. Our research shows that Styrofoam will keep the temperature fairly

constant inside the payload, which will ensure that no substantial moisture collects on

the electrical devices.

Since Styrofoam is a ductile material that cannot absorb a great amount of

energy, the structure will be covered with a composite material. This material will

consist of a carbon fiber that will be hardened with a resin. This hard, durable shell will

assist in protecting the structure from impact forces caused by the ground and any other

unforeseen projectiles the satellite may encounter. Carbon fiber was chosen because

of its ability to shield against radiation. The radiation should be negligible, however, in

the event that it becomes a problem, the package will provide a safe housing for the

electrical components.

The FAA requires that the weight distribution be that the force per area does not

exceed three psi. The calculated distribution on our structure is .083 psi with the max


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weight of twelve lbs. as the force. The area came from the structures seen in Figures

10.1.4 and 10.1.5:

Figure 10.1. 4 - Top View of Satellite


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Figure 10.1. 5 - Front View of Satellite

The structure was designed to have extra cargo space for payloads that will be

added later. The parachute, balloon attachment device, and the actual balloon will be

modeled using similar software after all components have been added to the inside of

the structure. The structure is scheduled to be completed by the first of March. The

structure will not be completed until all components have been tested and the system

works properly. The final structure will be designed, fabricated, and will have the

components placed securely inside.

The group has made preparations to modify the design if for any reason it does

not comply with FAA regulations. These modifications may include dividing the

structure into two six-pound structures instead of one twelve-pound structure. If this

situation occurs, the same materials and basic design will be used on a smaller scale.

There would have to be substantial changes made on how the two separate structures

would be joined to the same balloon. A back up design is in progress, which will

prepare the team to make any changes if necessary.


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10.2 Electrical Engineering

The Electrical Engineering (EE) Team shall build two data systems, an onboard

system and a ground system. The systems shall function together to broadcast real-

time telemetry including temperature, pressure, land position (longitude, latitude, and

altitude) data. The systems shall also broadcast real time video from the satellite of the

mission to the ground and accommodate for various payloads. The video of the mission

will inspire student interest in space exploration.

The EE team was further broken into subsystems, which can be seen in figure

10.2.1. This allowed team members to concentrate their research on one specific

device. This would also enable the EE team members to fulfill their requirements for

senior project. Each member was required to submit a specification sheet on their

particular device and explain how it would interface with other components. With the

completion of the specification sheets the team was able to better understand what the

system would look like and how it would function.


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Figure 10.2 1 - EE Work Breakdown Structure

The Electrical Engineers were required to work on components that were both in

the satellite and on the ground. Figure 10.2.2 shows the satellite system which will be

discussed first.


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Figure 10.2 2 - Satellite Functional Block Diagram

PowerWe will be using a rechargeable variable lithium battery as seen in Figure 10.2.3.

It will be purchased from Palm Energy Battery Company. The dimensions of the battery

are 65mm by 78mm by 27mm and weighs 85g. The voltage ranges from 3-18V and the

amperage/hours can range from 2Ah to 6Ah according to the voltage setting. We will

provide two batteries arranged in series. The batteries will be fully charged after sitting

on the charger for 110 minutes. We will also set a battery meter in the satellite. The

battery charger is based on the theory that a battery loses voltage thrust as the power is

depleted through use. The battery meter will send information though the antenna to


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the ground station telling the team members how much power is still left to facilitate the

onboard components.

Figure 10.2 3 - Rechargeable Variable Lithium Battery

Termination

As the balloon rises higher into the atmosphere, our sensors will indicate the

pressure decrease. This is due to the fact that air and water molecules that are in the

atmosphere have weight and so are more condensed in lower atmospheres. The

balloon is sealed, and so, its internal pressure will stay constant. As the balloon

reaches higher altitudes, it will expand to compensate for the drop in pressure. When

the balloon reaches the height of 100,000ft the internal pressure of the balloon should

be significantly higher then the external air pressure, forcing the balloon to burst. This is

the first method of termination. FAA requirements state that we need to also place a

second method of termination onboard as well. The devise we will build ourselves will

consist of a long coil of wire that will extend out of the satellite. This wire will surround

the bottom of the expanded balloon. This is the second method of termination. If the

occasion should arise, the ground team will command the balloon to burst. The

command will basically be the process of sending a signal to the satellite that will trigger


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a voltage charge, via a transistor, through the wire. This wire will build up the static

charge on the surface of the delicate latex balloon, forcing it to burst. How many volts?

How long will this take?

Sensors

In order to properly and efficiently meet the sensor requirements, an all-in-one

sensor was introduced. The Madge Tech PRTemp101, as seen in Figure 10.2.4, is

capable of simultaneously recording barometric and temperature data within our

required range of -40C to 80C and comes equipped with a real-time clock for data

time/date stamps. It is self-powered with an internal 3.5V lithium battery thereby

eliminating extra space and time needed for an external interface. The unit transfers

data through a serial port that will in turn be routed to the internal Motorola 6812 for

direct communication to ground control. In the event data transfer is lost, the sensor

has an internal memory unit that records all data obtained within its usage. Weighing

only 2 oz. and capable of withstanding the harsh environment, the Madge Tech sensor

was considered to be the most time and space efficient method in accomplishing the

satellite requirements.

Figure 10.2 4 - Temperature and Pressure Sensor


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Figure 10.2 7 - Recommended 12-pin setup

The antenna connector is a 50 MCX connector. It is recommended that the antenna

is placed in an open line of sight, which should pose no problem because of the nature

of our project. The word order output is specified in the Garmin GPS 25 manual. In

order to use the data outputted from the GPS it is necessary to capture the date with the

HC12. The data will be captured and it will be stored on board the satellite as well as

decoded on the ground.

ATV

The Amateur Television (ATV) system consists of three parts: ATV transmitter,

two camera switching system, automated and manual control system. The ATV

transmitter will be purchased. Two video cameras will also be purchased from Ingram

Technologies, LLC and are seen in Figure 10.2.8.


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Figure 10.2 8 - ATV Transmitter

The ATV transmitter, as seen in Figure 10.2.9, was designed primarily for Radio

Control models, Rockets, Balloons, etc. with its small 1.8x3.5 inch size and 2-oz.

weight. The ATV transmitter transmits a video signal in the 70cm band. The ATV has

adjustable power output from 1.5 peak envelope power (pep) to 100 mW. Draws 350

mA at 13.8 V at 1W, 200 ma at 100 mW, runs on 11 to 14Vdc. Crystal frequency:

426.25 MHz but will work with 427.25, 434.0 and 439.25 MHz.

Figure 10.2 9 - Two Input Analog Switching System with Digital Control


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The digitally controlled analog switching system takes two 1-volt peak to peak (p-

p) analog signals and outputs a single output 1-v p-p analog. The control signal is taken

from the output of the multiplexer configuration shown in Figure 3. When the control

signal is high the signal from camera 2 is being outputted and camera 1 is off.

Conversely when the control signal is low camera 1 signal is outputted and camera 2 is

off. This system requires a 10-volt source connected to the source terminals of the

transistors and a transistor to transistor standard logic (TTL) control signal. The circuit

was subsequently tested utilizing two camcorder video RCA output signals tied into the

analog input ports on the circuit. Visually there was no apparent noise in or loss of video

feed. The switching signal transient was small enough for little or no visual distortion

between switching cycles. Tests will be conducted in order to qualify the operation

mode of the transistors and to quantify the signal to noise ratio of the entire system.

Figure 10.2 10 - Two Input Multiplexer

The automated and manual control device is a two to one multiplexer with one

input tied to a 555 timer with a 60 second period and a 50% duty ratio, the other input is

connected to the microprocessor shown in Figure 3. The control line is also tied to the


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microprocessor. The output line is connected to the control signal input on the switching

system. When the control line on the multiplexer is high, the output will be that of the

timer allowing for 30 second of feed from each camera. When it is low the output will

come from the microprocessor allowing for manual control because the input from the

microprocessor will be controllable from the ground.

Data Systems

The Data System will be constructed around the Motorola Adapt 6812. The

M68HC12 is a micro-controller that operates at a speed of eight mega-hertz and is

capable of sixteen-bit processing. Efficient arithmetic and math operations are

performed through full sixteen-bit data paths. The 6812 is a proper superset of the

industrial standard M68HC11. The Adapt812 is an evaluation board that utilizes the

many features associated with the M68HC12 micro-controller and provides easy access

through two headers, each consisting of fifty pins. The evaluation board requires 9V DC

and approximately 300mA. From the headers the Analog to Digital Converter (ATD),

Standard Timer Module, Multiple Serial Interface, as well as many other features can be

readily implemented.

All devices interfacing with the M68HC12 will be accomplished through a RS 232

(9-pin Serial) connection. This connection will standardize the connection of all the

devices to the microcontroller. The full functional ability of the serial port will be

available. This means that two way communications will occur if needed. The payload

will be allotted one byte (eight bits) in any one command string. There will be no limit

on the amount of commands sent to the balloon satellite. The micro-controller on the

satellite will run in ten second loops. What this means is that there will be a scan for


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any received traffic once every ten seconds. Upon the raising of a flag the micro-

controller will pass the data to the correct serial port i.e. the correct device. The Most

Significant Bit (MSB) will be the flag for the micro-controller. When there are

commands the MSB will be in the one or high state and cause the micro-controller to

jump to a subroutine that will pass the data on to the correct device. When there is no

traffic received the MSB will stay in the zero or the low state.

To utilize the commands from Ground Control the payload must have a

predetermined code for the command string. This will involve collaboration with the

Ground Controls Software Specialists in order to incorporate the correct characters to

be sent in the correct order. Of course, all aspects of the above discussion hinge on

whether or not the payload has a device, such as a micro-controller, capable of

decoding the data and utilizing it in the desired way.

To accomplish this interfacing with the M68HC12 a Universal Asynchronous

Receive/Transmit (UART) will be used. The Texas Instruments TL16C554A is an

enhanced quad-channel asynchronous-communications element. The TL16C554A

provides serial-to-parallel conversion of data from the devices and parallel-to-serial

conversion of data from the M68HC12. The UART will have a working voltage of 5V DC

and dissipate 50mA of current. Two four-channel UARTs will be used to create an

eight-port serial-bus.

Standard serial ports require 12V DC. To create the needed voltage a MAX

232, Multi-channel RS 232 Driver/Receiver, will be used. The device is specially

designed to work with battery-powered systems such as the satellite. The MAX 232

has a DC operating potential of five volts with a max current draw of 30mA. Each MAX


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232 will support operations for three channels (serial connections) and will be

implemented in conjunction with the other devices needed to create an operational

eight-port serial-bus.

In addition to the transmission of all telemetry to ground control the data system

must provide storage on-board. An Electrically Erasable Programmable Read Only

Memory (EEPROM) will provide the needed space. The EEPROM will be directly linked

to the M68HC12.

To provide a command link with ground control a port from the M68HC12 will be

allotted. This port will output a signal only and will be known as a Control Bus. The

control bus will consists of five lines each of which will send either a high (+5V DC) or

low (0V DC) signal to those systems requiring remote operations. These systems will

include flight termination, ATV power shut down, camera switching, and two lines for

payload. The flight termination is a safety precaution and is a requirement set forth by

the FAA. Upon reaching 100,000ft, if the balloon has not burst, a command will be

issued from ground control to terminate the flight. The continuous transmission of video

poses a power failure contingency that will be remedied with a transmitter power shut

down command. In addition to the power shut down, the dual camera system will have

ground controlled switching in an effort to achieve the best perspective. The payload

will be supplied with two command lines, which will be operated from ground control.

Both lines will supply the same signal as previously mentioned.


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Packet Radio

All data that is being passed from satellite to the mobile ground control station is

required to pass through the packet radio. This includes the GPS system, telemetry

and payload telemetry. Packet radio is the radio equivalent of a computer modem. The

packet radio will be hard connected to a microprocessor system and compile the

information into packets and send it to another packet radio via radio waves. For our

specific purposes we will be purchasing a packet radio system purchased through

Hamtronics, http://www.hamtronics.com.

Packet radio will be used in sending data and receiving commands to the satellite

for the purpose of this project. The data and commands are broken into two

frequencies on two different bands. The bands that will be in use are the 2m and the

70cm bands. Different frequency bands are used, because there is a limited bandwidth

of one thousand two hundred (1200) baud. Also, there are limited frequencies allocated

to packet radio use. Both components are shown in Figures 10.2.12 and 10.2.13.

Through the use of packet radio the 2m band will be used for data transmission

for GPS data, telemetry and payload. The commands to control termination, camera

selection and a hi/low signal reserved for payload will be sent through the 70cm band.

The command will include switching of the two video cameras, shut off for video

transmission, and shut off for payload.


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Figure 10.2 11 Transmitter for 2m Band

Figure 10.2 12 - VHF Receiver for the 70cm Band

Satellite Antennas

The Balloon Satellite will use two Amateur Radio Bands to transmit and receive

data. On the Satellite, the 70cm (439.25 MHz), Little Wheel Antenna, as seen in Figure

10.12.14, will be used to send a streaming video signal to the ground station. This

antenna will also be used to receive packet radio commands from the ground control

station. The Little Wheel Antenna is selected, because it will perform well under the

predicted conditions of the ascent and descent. The predicted conditions involve

spinning which can cause nulls in the radiation pattern of the antenna. The Little Wheel

Antenna is an omni-directional antenna that consists of three one-wavelength elements


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Figure 10.2 14 - 2m Dipole Antenna

Figure 10.2 15 - 2m Dipole Antenna

Figure 10.2 16 - Ground Control Design

The PC Electronics 17 boom omni-directional antenna will be used to receive the

ATV signal on the 70cm band and transmit data to the balloon satellite. This antenna

has 16 dBd gain. One important consideration of the antenna is the height and

placement. Line of sight is essential for quality communication. The frequency used


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will be 439.25 MHz, which corresponds to channel 60 on a normal UHF/VHF television.

All that is required to display the video is to connect the antenna to the television tuned

to channel 60. The live video feed will be captured on a VCR as well as viewed

throughout the flight.

The Cushcraft A-148-20s Beam Antenna will be used to receive data on the 2m

band from the balloon satellite. The Cushcraft Antenna has 16.2 dBd gain. The

Cushcraft Antenna will be connected to a 2 meter ICOM IC 2720. The information

being received will be from the sensors and GPS. The data will be received though the

antenna which is connected to a PacComm TNC. The TNC converts the radio signal

into data that can be processed by the computer using hyperlink. The data will be

displayed in a graphical user interface (GUI).

10.3 Computer Science

List of Displays quantify workDocument your display requirements

CmdSee data

The information gathered on the satellite will be transmitted to the ground

system. The CS team will focus on software development for the ground station. Data

gathered from the satellite will be received to the ground system through a serial port.

This information will be continuously received, recorded, analyzed, and displayed.

Modular programming will be implemented in the software, and the code writing will be

completed in C/C++ and Visual Basic. The work being completed by the Computer

Science team can be seen in figure 10.3.1.


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Figure 10.3 1 Ground Station Software Flow Chart

Communication Port

A Com Port (Serial port) must be open to begin receiving data from the satellite.

Windows 98 will be utilized in order to access the computer port. The reason for this

decision is because accessing the port using an NT based operating system such as

Windows XP/2000 will not give direct access to the ports. In earlier operating systems,

such as the one chosen, a program can have direct access without going through

security check by the operating system. Once the port is opened, the real-time data will

stream into the waiting program and be able send commands to the satellite.

Data Flow Loop

The data flow loop will control the flow of information gathered into a database

and the main program simultaneously. The data measurements will be taken from the

satellite in a cycle, and the data flow loop will determine what cycle the data is in. This

will organize the information in the database for future use.


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Database

The database will record the measurements taken by the satellite during its

mission. This information collected in the database will be used in a detailed analysis of

the mission.

Bring to memory (buffer)

The data sent from the data flow loop will be configured in such a way that the

Data In Conversion stage can be completed efficiently.

Data In Conversion

The program, at this point, will have raw datadata in the format in which it will

be retrieved from the communication hardware is not available at this time. The raw

data will be converted into meaningful information that will be useful to the rest of the

program. This may include converting from binary to decimal or to the instrument from

which the information belongs. The data will then be sent to the data analysis stage for

calculations.

Data Analysis

Some calculations will need to be completed before displaying the data. Such

calculations include ascending and descending rates related to time and temperature at

certain altitudes. Data analysis includes ensuring all data required for display is

available on time.


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Display

From the display windows, the user will be able to see all the information in real

time. At this stage, the data will be displayed in a meaningful way. The different

windows will include the actual position of the satellite, and graphs on the ascending

and descending rates related to time and temperature at certain altitudes. The position

of the satellite will be displayed on a map according to the corresponding coordinates

given by the GPS system. The ascending and descending rates related to time and the

temperatures at certain altitudes will be calculated and displayed at every interval the

information is updated. There will be a separate window from where the user will have

the ability to send any desired commands to the satellite if needed.

Command Log

In the command log, a file will be created, which will store the commands and

sending times to the satellite that were conveyed throughout the duration of the flight.

Data Out Conversion

Because the communication hardware will required a separate data format, any

command that is sent to the satellite will have to be converted to such format. The

command will then be sent to the satellite through the communication port.


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10.3.1 Web Site Development

The Space Hogs (http://www.engineer.tamuk.edu/departments/eecs/csen/csen-

4201/) is up and running. In the site there are eight sections. Class Objectives section is

where the objective for the class goals and the requirements for the project. The Design

System has details of the projects basic model designs. The Documentation section

links all of the class documentation files that are related to the project. The Team Info

section contains information on how the team is structured for the project, which

includes individual students photos. The Schedule and Budget Section has the timeline

and other budget information. The Customers section documents the information on the

groups and organizations that the teams are serving. The Class Activities section

contains most of the activities that the class has done. The last section is the Links

section and this section provides links to useful areas and sites of some of our

customers. A copy of the Space Hogs home page is shown in the following picure.


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Figure 10.3.1.1 Space Hogs Main Page


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10.4 Civil Engineers

The Civil Engineers were responsible for establishing launch capability and

location, performing a ground track survey, and coordinating with the FAA. The work

being completed can be seen in Figure 10.4.1.

Balloon and

Parachute

Figure 10.4.1 CE Work Breakdown Structure

In order to determine launch capability and location, the civil engineers will

consider a location that will enable the balloon to have a land recovery. Civil engineers

will identify the location for launch and consider protection from wind, low population

areas, and communication capabilities.

From the research conducted, the group has discovered that once in flight, the

balloon is known to travel approximately 200 miles east from the launch site. The team

has been forced to find a location other than Kingsville, because if launched from this

area, there is a large probability that the balloon will land in the ocean, which will not

enable us to recover the satellite and reuse it. The launch site will also meet all FAA

regulations. List FAA requirements.

OperationsHandling

Procedures

Capability,Location

Ground TrackSurvey

FAACoordination

Locate Place ofLaunching

WeatherResearch

BalloonTrack Software

Recovery

Legal Process


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The group will coordinate the satellite launch with all proper officials well before

the launch time. Various agencies that will be contacted include: FAA, ATC, and local

police.

For ground track survey, the civil engineers will analyze the possible flight path

using tracking software. From the projected flight path, the group will be able to identify

if the balloon is projected to land on private property. If so, landowners will be

contacted in order to assure their cooperation when our group is attempting to recover

the payload. During flight, the balloon will be tracked by a radio or GPS system. The

balloon will be recovered using a parachute with a release mechanism to terminate the

flight.

11.0 Risk ManagementWhat is risk management? Risk management is the process of identifying any

possibilities for risks or failure and determining the probability and impact of the risk

items. Then the necessary mitigation is listed to address the risk item.

Every member of the team was required to provide two risk items that they foresee for

the future. Included is a compiled list of the received items and a breakdown of levels of

focus the group needs to apply.

Risk Action Items

Risk Item Probability Impact Mitigation Responsible Parties

1 Delayed design process High High Focus on design and notonly paperwork

All disciplines

2 Launch in Spring; Highwinds

Medium Low Research best launch site.Launch early morning and

watch weather to avoidwindy days.

All disciplines

3 Scheduling conflicts High Medium Less critical class time Tony Kim


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4 Delayed componentacquisition and purchase

Low High Discover ordering andconstruction timelines

All disciplines

7 Loss of students Medium Medium Insure all degreerequirements are met

All disciplines

8 Improper data acquisition Medium High Early completion for testing CS & EE

9 Inadequate software

systems

Medium Medium Early completion for testing CS & EE

10 Antenna failure Medium Medium Early completion for testing;Implementation of a back-

up system

EE

11 Weak and inadequateATV signal

Medium Medium Explore best possibilities;Signal strength and

capability test

EE

12 Antenna interference witheach other

Low Medium Research all possibilities;Conduct tests

EE

13 FAA complications Low Medium Early coordination;Follow all guidelines

All disciplines

14 Unfinished TSGCassignments

Medium Medium Good communication All disciplines

15 Inadequate testing of allsystems

Low High Early completion for testing All disciplines

16 Harsh antennaenvironment

Low High Properly research locationand attachment

EE & ME

17 Parachute does not open Low Low Test Parachute and balloondesign

ME

18 Satellite landing where itcannot be retrieved

Low High Proper launch site; Goodradio communication

Ground control

20 Theft upon landing Low High Quick recovery Ground control

21 Inability to terminate flight Low Low Testing of terminationsystem

Balloon team

22 Loss of line of sight toantenna

Low Low Adequate positioning ofantenna

All disciplines

23 Ground radio failure Low Low Back up system EE

Table 11.1 Risk Action Items

Impact

Low Medium High

Low 23 22 15--21

Probability Medium 9--14 6--8

High 4--5 2--3 1

Table 11 2 Level of Risk ChartWhere is range?

8 itemswe have a problem


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12.0 Future TestingWhen will the testing occur?

STRUCTURE AND MATERIAL ANALYSIS AND TESTING:

1. Non-destructive Testing

a. Finite Element Analysis Programi. An exact replica of the selected structure can be modeled in

3D1. The replica can be fixed at desired points and loaded in a

method to simulate the forces that will act on thestructure in possible conditions.

a. The FEA program can redraw the structureaccording to deflection under stress and show thestress areas by color-coding.

b. Different temperatures can be input to simulatemechanical properties of the structure at these

temperatures.c. Fluctuating loads can also be used.

b. Weight BalancingWill we use ballast? Extra weight??

i. The completed structure with the payload elements in theirdesired locations will likely have a center of gravity differentthan that of the symmetrical structure.

1. The new center of gravity is found using scales.a. The balloon and parachute mounting points can

be adjusted to balance the structure with the newcenter of gravity.

2. Destructive Testinga. Pull TestingWhat are you designing to?

i. The supports for the balloon and parachute must be able towithstand all forces encountered.

1. Gravitya. The supports must withstand the payload weight.

i. A factor of safety must be consideredb. The supports must withstand the force of the

payload under an acceleration of 5gs.How much time? Instantaneous 1 sec5 sec??

i. This will be [(5)*(weight payload)]ii. A factor of safety must be consideredb. Drop Testing

i. The structure must protect the payload elements upon impact.What type of forces will it get?

1. When the payload returns to the ground with theparachute deployed, it will reach an equilibrium speed.What is the equilibrium speed?


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a. The structure can be loaded with weights thatsimulate the payload elements and dropped froma selected height.

i. This height will be determined based on thespeed the structure will attain during the

end of its descent.1. A factor of safety must beconsidered. What is it?

ii. The surface the structure will impact will bebased on worst case scenarios.

1. Grass2. Asphalt3. Cement

ELECTRICAL TESTING:

3. Data Transmission TestingWHEN

a. Testing of Terminal Node Controllersi. The Terminal Node Controllers (TNC) will provide the link from

digital to radio. A nine-pin serial connection providesinterface between the TNC unit and digital processing unit.

1. Initial testing of TNC will consist of two TNC units hard-wired together with a standard transmission cable, eachof which is controlled with a desk-top computer.

a. Initialization of the TNC and parameter settingb. Test data will be transferred between the twoPersonal Computers.

2. The radio medium will be implemented using the 2m,144-148 MHz, band. Separate transmission cables willrelay the signal from each TNC to a complete radio (i.e.consisting of transmitter and receiver as well as allother components needed).

a. Construction of each radio and tuning of themedium transition components.

b. Test data will be transferred between both

Personal Computers using the TNC via theradio.4. Geographical Positioning and TrackingWHEN

a. GPS system Testing.1. The satellite will utilize a Geographical Positioning

System. The location of the satellite will be sent toground control and then relayed to recovery team.


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a. The GPS data will be displayed on a map atground control and relayed via radio to arecovery team.

5. Amateur Television TestingWHEN

a. Video Signal Reception Testing1. The Video Signal will be transmitted to Ground Controlfrom a remote location via 70cm (420-450MHz) band.The quality of the signal and its strength will beevaluated.

a. The Signal will be transmitted from differentlocations each of which is further away.

6. Power Consumption EvaluationsWHEN

a. Testing of Battery using Amateur Television (ATV) Signal1. The ATV transmission will occur from a remote location

and be powered by batteries only.a. The batterys rate of decay will be evaluated.7. Airplane TestWHEN

a.

13.0 Payload Requirements

Payload, for the purposes of this project, is defined as an experiment that will be

included in the satellite. This payload will either be designed by TAMUK students, or

created by another school. The Space Hogs team has preset the requirements and

restrictions for the payload. A requirement pertaining to the payload is that it will be

detachable. The weight shall not exceed 8.4 lbs. The size shall not exceed 2000 cubic

inches. The payload must have its own power. Finally the data connection for payload

will be provided through a serial connection and not exceed 8 bytes of data.

Temperature Req. / G Force Requirement

How do they mechanically secure?

When do they need to provide the payload to facility? Date?


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14.0 Projected Launch Day Operations

Prior to launch the ground control team will research and work with the software

to locate a proper launch site. On the day of the launch a specific team of at least 2

people from the ground control team will make sure that all the components in the

satellite that will function during the flight are working properly. The fully charged battery

will be attached and plugged in. The satellite team will run final tests on transmitters

and receivers from the ground, as well as to check that the antennas are working to

specifications both on the satellite and on the mobile recovery station. A separate team

of at least 2 people will work maintaining the balloon. These specialists will know how

to handle and inflate the balloon. The balloon will be inflated on top of a tarp at the

launch location. The balloon will not be touched by any skin oils and the persons

touching the balloon will be using latex gloves at all times to protect the surface and

structure of the balloon. Inflation will take about 20-30 min.

The payload and parachute will be attached to the balloon with the necessary

string according to the correct length measurements for best performance. Once the

balloon is ready, the payload is attached, and the final testing of the components is

done, we will then set up the launch and let the balloon go. Once the balloon is in air we

will immediately begin tracking the balloon via GPS system. The mobile tracking team

will be following the balloon on the ground to ensure strong data flow and proper pick

up.

Simulation ResultsWhere do we get the Helium? Safe operations.Where is the launch site?Contact information with the FAA, ATC, Police, Property owners


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15.0 Conclusion

The balloon satellite project will allow students from Texas A&M University-

Kingsville to complete a multidisciplinary two semester project that not only meets a

degree requirement but also allows students to gain valuable experience in

implementing a design and meeting requirements. Students are provided the

opportunity to explore space and get real, first hand experience with system

engineering! This project also helps build a close relationship between students and

faculty by encouraging students to seek help and suggestions from members of the

faculty.

By May 2004, the Space Hogs goal is to design, develop, and launch a balloon

satellite capable of recording relevant system and payload information. The satellite is

a facility capable of flying different payloads. The team will develop invaluable

professional skills throughout the project! Team members will obtain skills in

communication, teamwork, leadership, and learn the importance of time and budget

constraints. The completion of this project will give the team a chance to share the

knowledge and fascination of space exploration with future generations.


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16.0 Reference / Bibliography

An Introduction to APRS. 2 October 2003.

Automatic Position Reporting System. 3 October 2003. .

CarbCom. 27 September 2003. .

Detroit Amateur Television Society. 1 October 2003. .

Edge of Space Sciences. 21 September 2003. .

Edge of Space Sciences. The Edge of Space Sciences Handbook. Littleton, CO: Edgeof Space Sciences, Inc., 1993.

FiberGlass World. 19 September 2003. .

Information Unlimited. .

Ingram Technologies, LLC. .

MatWeb-Material Property Data. 9 October 2003. .

What Is Systems Engineering? Sandia National Laboratories. 23 September 2003..

Mable 2 Project: Michigan Area Balloon Launch Experiment 2. 1 October 2003.http://www.qsl.net/k8uo/UM201.htm.

EOSSMontana


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Appendix update

1.1 Schedule


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1.2 Budget and Expenses

Budget

Category Description Sub-Category Individual ItemCost

EstimatedCost

ActualItem Cost

ActualExpense

General

Medium / PresentationMaterial

$20.00 $1,140.00 $537.3

10/30/2003 IEEE CorpusPresentation

$81.08

Travel / Transportation $1,000.00

10/14/2003 Corpus Christi WeatherOffice

$272.25

Meeting Expenses $70.00

9/26/2003 Team Building BeachParty

$183.97

Copies / Report Binding $50.00

Satellite

Balloon $470.00 $0.0

Balloon $200.00

Balloon Rigging/Tarp $25.00

Digital Fishing Scale $10.00

Filling Device $5.00

Helium $200.00Regulator $20.00

Tank Rental $10.00

Parachute

Structures $200.00 $0.0Satellite ConstructionMaterials

$200.00

Insulation

Reflective Material

Communications $1,588.00 $144.0

2m Receiver Ground $169.00

2m Transmitter $220.00Antenna (Ground andSatellite)

$400.00

ATV Receiver $139.00

ATV Transmitter $150.00


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Cameras $300.00

GPS $150.00 $144.00

Testing with Airplane $60.00

Power $700.00 $0.0

Batteries $700.00

Instrumentation $100.00 $0.0

Unit $100.00

Data Systems $400.00 $0.0

Microprocessor $160.00

MemorySystem/Other

$240.00

Contingency $1,000.00 $0.0

Testing andReplacements

$1,000.00

Total $5,598.00 $5,598.00 $681.30 $681.3


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1.3 Work Breakdown Structure

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