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PACER Summer ProgramFlight Readiness Review Document

For theHATPaC

High-Altitude Thermodynamics Profile and Clarity Experiment

ByTeam PACER-GSU

Prepared by: Johnte Bass Date

Herman Neal Date

Matthew Ware Date

Submitted: Reviewed: Revised: Approved:

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Institution Signoff (replace with name) Date

LA SPACE Signoff Date

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Title: FRR Document for Pacer ExperimentDate: 07/13/2007

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TABLE OF CONTENTS

Cover.............................................................................................................................................iiChange Information Page............................................................................................................iiiStatus of TBDs.............................................................................................................................iiiTable of Contents.........................................................................................................................ivList of Figures..............................................................................................................................viList of Tables..............................................................................................................................vii

1.0 Document Purpose..................................................................................................................11.1 Document Scope...............................................................................................................11.2 Change Control and Update Procedures...........................................................................1

2.0 Reference Documents.............................................................................................................1

3.0 Goals, Objectives, Requirements............................................................................................13.1 Mission Goal.....................................................................................................................13.2 Objectives.........................................................................................................................13.3 Science Background and Requirements ...........................................................................23.4 Technical Background and Requirements........................................................................3

4.0 Payload Design.......................................................................................................................64.1 System Desing..................................................................................................................64.2 Electrical Design.............................................................................................................104.3 Software Design..............................................................................................................164.4 Thermal Design...............................................................................................................184.5 Mechanical Design..........................................................................................................18

5.0 Payload Development Plan...................................................................................................20

6.0 Payload Construction Plan....................................................................................................206.1 Hardware Fabrication and Testing..................................................................................206.2 Integration Plan...............................................................................................................216.3 Software Implementation and Verification.....................................................................216.4 Flight Certification Testing.............................................................................................21

7.0 Mission Operations...............................................................................................................257.1 Pre-Launch Requirements and Operations.....................................................................257.2 Flight Requirements and Operations..............................................................................257.3 Data Acquisition and Analysis Plan...............................................................................26

8.0 Project Management.............................................................................................................288.1 Organization and Responsibilities..................................................................................288.2 Configuration Management Plan....................................................................................288.3 Interface Control.............................................................................................................28

9.0 Master Schedule....................................................................................................................29

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9.1 Work Breakdown Structure............................................................................................299.2 Staffing Plan....................................................................................................................319.3 Timeline and milestones……………………………………………………………….31

10.0 Master Budget.....................................................................................................................3110.1 Expenditure Plan...........................................................................................................3210.2 Material Acquisition Plan.............................................................................................32

11.0 Risk Management and Contingency...................................................................................32

12.0 Glossary .............................................................................................................................33

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LIST OF FIGURES

1. Figure on expected science results................................................................................Figure 12. Figure on expected science results................................................................................Figure 23. Block diagram of payload systems................................................................................Figure 34. Block Diagram of power system...................................................................................Figure 45. Block Diagram sensor electronics.................................................................................Figure 56. Block Diagram of EEPROM.........................................................................................Figure 67. Schematic of sensor electronics.....................................................................................Figure 78. Schematic of power system...........................................................................................Figure 89. Flight software flow chart.............................................................................................Figure 910. External Top View....................................................................................................Figure 1011. External Left Side View............................................................................................Figure 1112. External Right Side View..........................................................................................Figure 1213. Lid Top View............................................................................................................Figure 1314. Lid Side View............................................................................................................Figure 1415. Internal Top View w/o BalloonSat............................................................................Figure 1516. Internal Top View w/ BalloonSat..............................................................................Figure 1617. Pressure Calibration Graph…………………………………………………………Figure 1718. ADD22100 Calibration Graph..................................................................................Figure 1819. Diode Calibration Graph...........................................................................................Figure 1920. Pre-Flight software flow chart...................................................................................Figure 2021. Post-Flight software flow chart.................................................................................Figure 2122. Ground software flow chart.......................................................................................Figure 2223. Work Breakdown Structure.......................................................................................Figure 23

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LIST OF TABLES

1. Goals versus measurement traceability matrix...............................................................Table 12. Power budget table..........................................................................................................Table 23. Data format and storage..................................................................................................Table 34. Weight budget table........................................................................................................Table 45. Organization and Responsibilities..................................................................................Table 56. Expenditure Plan.............................................................................................................Table 67. Project budget.................................................................................................................Table 78. Material acquisition plan……………………………………………………………….Table 89. Risk management table…………………………………………………………………Table 910. Contingency Table……………………………………………………………………Table 10

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1.0 Document Purpose

This document describes the Flight Readiness for the High-Altitude Thermodynamics Profile and Clarity (HATPaC) experiment by PACER-GSU for the PACER Summer Program. It fulfills part of the PACER Summer Program Project requirements for the Flight Readiness Review (FRR) to be held July 30, 2007.

1.1 Document Scope

This FRR document specifies the scientific purpose and requirements for the High-Altitude Thermodynamics Profile and Clarity experiment. The document includes details of the payload design, fabrication, integration, testing, flight operation, and data analysis. In addition, project management, timelines, work breakdown, expenditures and risk management are discussed.

1.2 Change Control and Update Procedures

Changes to this FRR document shall only be made after approval by designated representatives from Team PACER-GSU and the PACER Institution Representative. Document change requests should be sent to Team members, the PACER Institution Representative and the PACER Project.

2.0 Reference Documents

1. Trickle-Charge Time Keeping Chip (DS 1302) data sheet2. Pressure Sensor (model 1210) data sheet3. Basic Stamp Command (12CIN) data sheet4. EEPROM (24L64) data sheet5. Voltage Reference/Temperature Sensor (AD780) data sheet6. Voltage Output Temperature Sensor (AD 22100) data sheet7. B. Gerts and E. Linacre, “The height of the troposphere,”

(http://www-das.uwyo.edu/~geerts/cwx/notes/chap01/tropo.html), November 1997.8. University of Wyoming College of Engineering Department of Atmospheric Science

Upper Air Soundings (http://weather.uwyo.edu/upperair/soundings.html)

3.0 Goals, Objectives, Requirements

3.1 Mission Goal

Investigate the temperature, pressure, density and clarity as a function of altitude up to about 100,000 feet in order to study layering in Earth’s lower atmosphere.

3.2 Objectives

3.2.1 Science Objectives

1. Identify the zones of the Earth’s lower atmosphere.2. Determine the altitude of the tropopause.3. Develop a temperature profile of the atmosphere.

Team PACER-GSU FRR v1.31

http://www-das.uwyo.edu/~geerts/cwx/notes/chap01/tropo.html

4. Develop a pressure profile of the atmosphere.5. Develop a density profile of the atmosphere.6. Qualitatively evaluate atmospheric clarity as altitude varies.7. Compare accepted models of the atmosphere to measurements.8. Present findings.

3.2.2 Technical Objectives

1. Build and fly a payload and retrieve the data.2. Measure temperature over the range -80 ˚C ≤ T ≤ 40 ˚C.3. Measure pressure over the range 5 mbar ≤ P ≤ 1000 mbar.4. Calculate the atmospheric density using the ideal gas law.5. Take photographs of the external environment using two onboard cameras for the

duration of the flight. The two cameras will provide an overlapping field of view from 10˚ above the horizon to 60˚ below the horizon.

6. Store thermodynamic data in memory contained within the payload control computer and photographic images in flash memory within the cameras.

7. Correlate payload data with mission telemetry data to determine the altitude of each measurement.

3.3 Science Background and Requirements

3.3.1 Science Background

This payload will ascend through the troposphere, the tropopause, and into the stratosphere to the upper boundary of the ozone maximum.

The word troposphere comes from tropein, meaning to turn or change. All of the earth's weather occurs in the troposphere. It extends from the earth's surface to the tropopause. Within the troposphere, the temperature generally decreases with increasing height, dropping from an average of 15 ˚C (59 ˚F) near the surface to an average of -57 ˚C (-71 ˚F) at the tropopause.

The tropopause is the transition layer between the troposphere and the stratosphere. It begins where the temperature no longer varies with height. On average, the lower boundary of the tropopause has an altitude of 12 km (7 mi); the upper boundary, an altitude of approximately 21 km (13 mi).


Figure 1

2

Figure 1 represents a typical profile of the layers of the atmosphere. However, the specific profile depends on location, particularly the latitude. There is also a seasonal variation. For example, over Australia the height of the tropopause varies from 12-16 km at midyear to 16 km at year-end. At latitudes above 60˚, the tropopause is less than 9-10 km above sea level. The lowest tropopause is less than 8 km above Antarctica and above Siberia and above Siberia and northern Canada in winter. The highest average tropopause is over the oceanic warm pool of the western equatorial Pacific, about 17.5 km high, and over Southeast Asia. During summer monsoon, the tropopause occasionally peaks above 18 km. The HATPaC experiment will measure the profile over East Central Texas (35˚ latitude) in midsummer.

The tropopause is characterized by a region several kilometers thick where the temperature is relatively constant. High altitude sounding measurements [7] indicates that temperature over 2 km altitude range varies 3 ˚C or less. In order to identify this region, it is necessary to make several measurements while the payload is within the boundary layer. These measurements most are capable of resolving temperature changes smaller than the expected variation.

The atmosphere can be treated as an ideal gas. Therefore, the ideal gas law may be used to calculate the density of the atmosphere from measurements of the temperature and pressure:

where ρ is the density, P is the pressure, T is the temperature, R is the ideal gas constant, and M is the effective molecular mass of the atmosphere. A typical sounding in the tropopause (P = 100 mbar, T = -70 ˚C, altitude = 16,600 m) yields a mass density ρ = 1.7 10-4 g/cm3, which is consistent with Figure 2.

These considerations lead to the requirements in the following section.

3.3.2 Science Requirements

1. Make measurements every 15 seconds.2. Calculate density to within 5% uncertainty which require:

a) Measure temperature to within 1 ˚C (0.5% at the tropopause).b) Measure pressure to within 5 mbar (5% at the tropopause).

3. Determine altitude to within 100 meters.4. Take photographs during ascent and descent every 15 seconds up to an altitude of

100,000 feet.

3.4 Technical Background and Requirements


Figure 2

3

3.4.1 Technical Background

The experiment is performed by an instrument payload which is secured between two strings beneath a latex helium sounding balloon. The payload will rise at an approximate rate of 850 ft. per minute. The experiment will operate for the duration of the flight which is approximately three hours. The payload is self-contained with respect to electric power, computer control, and data storage. It will rely on a GPS beacon located in another payload on the flight string for latitude, longitude, and altitude.

The payload will take measurements of temperature inside the payload capsule, outside the payload capsule, and ambient pressure. Two onboard cameras will photograph the environment with an overlapping field of view of approximately 70 degrees in the vertical dimension. Photographs are taken at the same time as the pressure and temperature measurements. Pressure and temperature measurements are time stamped. The time stamp will allow payload-based measurements and images to be correlated with GPS data in post-flight data analysis.

Interior temperature is measured using an Analog Devices AD780 combination voltage reference and temperature sensor which provides an output of approximately 560 mV at 25 ˚C varying at the rate of 1.9 mV/˚C.

Exterior temperature is measured using a pair of sensors. One is an Analog Devices AD22100, which provides an output of 1.375 V at 0 ˚C, varying at the rate of +22.5 mV/˚C. However, the AD22100 is not specified for operation below -50 ˚C. The payload is expected to encounter temperatures lower than -50 ˚C during the flight. Therefore, an additional temperature sensor is needed.

A silicon PN-junction diode exhibits a forward biased voltage whose temperature-dependence is about 2.5 mV/˚C. Therefore, a simple silicon diode may be used as a temperature sensor. Experience has shown that the diode is useful as a sensor down to cryogenic temperatures. The payload will include a forward-biased PN-junction diode as an additional temperature sensor.

Pressure is measured by an ICSensors Model 1210 silicon pressure sensor. The sensor is configured as a Wheatstone bridge in which the branches of the bridge are piezoresistive elements whose resistance varies in response to mechanical stress. The bridge circuit requires a constant current source for proper operation.

These measurements will initially be in the form of analog voltages in the range 0-2.5 V. An analog-to-digital converter (ADC) will digitize these data into 8-bit binary numbers which can be stored in nonvolatile EEPROM memory within the BalloonSat.

All of the measurements are made under the control of a BASIC Stamp microprocessor and archived in EEPROM nonvolatile memory. These devices are integrated with the BalloonSat and share its power. Power for the BalloonSat is provided by a 12 V lithium battery pack comprised of a pair of 6 V lithium camera batteries.

Photographs are taken with a pair of VistaQuest VQ1005 1.3 Mega-pixel (nominal) digital cameras triggered by relays operated under control of the BalloonSat. Images are stored in JPEG format on 512 MB Secure Digital flash memory cards (non-volatile memory). The two cameras are synchronized so each image pair may be combined post-flight into a single wide-field image.


Cameras will require power at a voltage level of 1.5 to 3 volts, which is provided by lithium batteries.

3.4.2 Technical Requirements

1. Payload must remain intact from launch to recovery.2. Power system must operate over the temperature range -80 ˚C ≤ T ≤ 40 ˚C with the

capacity to power the BalloonSat, sensors, and data archive for the duration of the flight.3. Temperature sensor able to measure over the range -80 ˚C ≤ T ≤ 40 ˚C.4. Pressure sensor able to measure over the range 5 mbar ≤ P ≤ 1000 mbar.5. Camera able to operate over the temperature range -80 ˚C ≤ T ≤ 40 ˚C and pressure range

5 mbar ≤ P ≤ 1000 mbar.6. Record time to 15 second accuracy.7. Data archive system with the capacity to store measurements by the sensors and real time

clock for the duration of the flight (approximately 750 data records)8. Photograph storage media with the capacity to store about 1500 1.3 Mega-pixel (1600 ×

1200 pixels) images.9. Ground system which can download, analyze, and graphically display payload

measurements.


4.0 Payload Design

The payload will consist of a capsule enclosure constructed foamed polystyrene sheet that can be attached to the flight-support lines. Contained within the capsule is a BalloonSat control computer and matching daughtercard. The daughtercard will contain circuitry for analog signal conditioning and relays for camera control. Also enclosed within the payload capsule are two digital cameras. The capsule contains separate fused-protected battery packs will supply power for the cameras, BalloonSat, and daughtercard.

4.1 System Design

POWERSUBSYSTEM

SENSORSUBSYSTEM

BALLOONSATSUBSYSTEM

DATA ARCHIVESUBSYSTEM

GROUNDSUPPORT

SUBSYSTEM

ANALOGDIGITAL

DIGITAL

DIG

ITAL

MECHANICALSUPPORT

SUBSYSTEM

THERMALSUBSYSTEM

Figure 3


4.1.1 Functional Components

MechanicalThe payload capsule will hold all instruments for the payload. It is a right hexagonal prism approximately 22 cm high and approximately 19 cm in its longest lateral dimension. A small auxiliary compartment is attached to one hexagonal facet to support and protect the digital cameras. An additional polystyrene foam panel which supports the BalloonSat, daughtercard, and battery packs slides into the interior of the capsule and is held in place by the lid and the bottom panel.

The capsule is attached to the flight support strings by a pair of tubular channels which pass though the top, bottom, and walls of the capsule. The channels are lined with plastic tubing to protect the flight strings from abrasion.

The exterior of the capsule is covered with aluminized mylar film which enhances the structural integrity of the package, and, as is discussed below, improves its thermal properties.

ThermalThe payload capsule is expected to encounter temperatures below the operating range of the instrumentation within. Thus, the capsule must protect the instruments from these extreme conditions. The package is constructed so as to limit heat loss. The polystyrene foam used to construct the capsule provides thermal resistances of R-4 through the capsule’s sidewalls and R-8 through its bottom and lid. The aluminized mylar film has high reflectivity which reduces thermal radiation losses. In addition to passive control of thermal losses, the instruments will convert electrical energy into heat during the flight, which will mitigate thermal losses through the insulation and radiation barriers.

PowerLithium batteries are used to power all electronic devices within the payload. They perform well at low temperatures and have excellent energy to weight ratio. The specific requirements for battery performance are discussed in detail in Section 4.2.5 (Power Budget).

As shown in Figure 4, all battery packs are connected via protective resettable fuses. This type of fuse will disconnect the battery from its load if an overcurrent condition exists, but will reapply power once the fault condition is cleared. Thus a momentary short circuit or overcurrent condition will not permanently terminate payload operation.


Figure 4

7

SensorsFigure 5 below illustrates the configuration of the payload sensors. The sensor complement includes three temperature sensors, one pressure sensor, and two digital cameras. One temperature sensor will measure the temperature inside the payload capsule. Two temperature sensors will measure the temperature outside the payload capsule. The pressure sensor will measure the pressure inside the capsule. Because capsule is not sealed, the pressure inside the capsule is equal to the pressure outside. Two digital cameras will combine to take pictures with a vertical field of view from 10 ˚C above the horizon to 60 ˚C below the horizon.

ProcessorA BASIC Stamp processor is integrated with the BalloonSat. The control program is contained within nonvolatile EEPROM memory on the BASIC Stamp. Program execution begins immediately upon application of power to the BalloonSat without addition user intervention.


Figure 5

8

Figure 6Data ArchiveAn 64 kB EEPROM onboard the BalloonSat is used to store data collected by temperature and pressure sensors as well as a time stamp provided by the Balloonist’s RTC. These are retrieved by executing a post-flight BASIC Stamp program while monitoring the BalloonSat serial communications port with a terminal emulator program (Term232). This memory capacity will allow up to 6500 10-byte data records to be stored. This capacity represents 27 hours of payload operation. Flight control software includes provisions to prevent data from being overwritten if payload recovery takes more than 27 hours.

Each of the two digital cameras includes a 512 MB Secure Digital card. This card capacity is enough to store over 3 thousand 1600 × 1200 pixel images using 16:1 JPEG compression. Images may be recovered by either using a USB cable to connect the camera directly to a computer or by removing the card and inserting it into a card reader that is connected to the computer by a USB cable.

4.1.2 Component Interfacing

A 12 volt battery is electrically wired to the BalloonSat, the sensors and the EEPROM and supply voltage throughout it. Control signals are sent to the sensors from the BalloonSat and in return the BalloonSat will receive wired analog data from the sensors. The EEPROM is receiving and sending digital data to and from the BalloonSat. The ground support system is interfaced to the EEPROM and the BalloonSat via digital data. The mechanical support system is interfaced mechanically to both the BalloonSat circuit board and the thermal system. The thermal system is interfaced thermally to both the BalloonSat circuit board and the mechanical system.

4.1.3 Traceability

Requirement Subsystem Implemented

Method of Verification Successful Test Verification

Measure temperature to within 1 ˚C. Sensor Subsystem Calibrate temperature sensor down to dry ice temperature.

26 July 2007

Measure pressure to within 5 mbar. Sensor Subsystem Calibrate pressure sensor between atmospheric pressure and a vacuum.

25 July 2007

Calculate density to within 5% error. Sensor Subsystem Ground System

Test Excel spreadsheet using a known set of temperature and pressure values.

Make measurements every 15 seconds. Sensor Subsystem Simulate a flight in the laboratory.

25 July 2007

Determine altitude to within 100 meters. Sensor Subsystem Ground System

Correlate time stamps for simulated flights with GPS data from previous flights.

Take photographs up to an altitude of 100,000 feet.

Sensor Subsystem Simulate a flight in the laboratory for the expected


Requirement Subsystem Implemented

Method of Verification Successful Test Verification

duration of the flight.Payload must remain intact from launch to recovery.

Mechanical Subsystem Perform vacuum tests, cold tests, and drop the payload from a height of 8 feet onto a turf surface.

25 July 2007

Power system must operate over the temperature range -80 ˚C ≤ T ≤ 40 ˚C with the capacity to power the BalloonSat, sensors, and data archive for the duration of the flight.

Power SubsystemMechanical SubsystemThermal Subsystem

Simulate a flight in the laboratory down to dry ice temperature.

24 July 2007

Temperature sensor able to measure over the range -80 ˚C ≤ T ≤ 40 ˚C.

Sensor Subsystem Calibrate temperature sensor down to dry ice temperature.

26 July 2007

Pressure sensor able to measure over the range 5 mbar ≤ P ≤ 1000 mbar.

Sensor Subsystem Calibrate pressure sensor between atmospheric pressure and a vacuum.

25 July 2007

Camera able to operate over the temperature range -80 ˚C ≤ T ≤ 40 ˚C and pressure range 5 mbar ≤ P ≤ 1000 mbar.

Sensors SubsystemMechanical Subsystem

Simulate a flight in the laboratory for the expected duration of the flight.

Synchronize data acquisition to time stamp within 7 seconds.

Sensors Subsystem Correlate time stamps for simulated flights with GPS data from previous flights.

23 July 2007

Data archive system with the capacity to store measurements by the sensors and real time clock for the duration of the flight.

Data Archive Simulate a flight in the laboratory for the expected duration of the flight.

23 July 2007

Photograph storage medium with the capacity to store about 2000 high-resolution pictures.

Data Archive Simulate a flight in the laboratory for the expected duration of the flight.

Ground system which can download, analyze, and present payload measurements.

Ground System Test post-flight software using data gathered during simulated flights.

24 July 2007

4.2 Electrical Design

4.2.1 Sensors

The physical parameters and the sensors used to measure them are listed below:

Parameter Sensor Output FormatInterior Temperature AD780 voltage signal-single endedExterior Temperature 1 AD22100 voltage signal-single endedExterior Temperature 2 1N457 voltage signal-single endedPressure ICS1210 voltage signal-differentialImaging 2 × VQ-1005 JPEG Compressed image

4.2.2 Sensor Interfacing

The pressure and temperature sensors will receive power from the main 12 volt battery pack. Each camera has its own 2 volt power source derived from a 3 volt lithium battery. The relays which control the camera derive power from the regulated 5 volt supply on the BalloonSat board. The 5 volt supply to the relays is protected by a resettable fuse.


Table 1

10

Pressure and temperature are in the form of analog voltages in the range of a few millivolts to a few volts. To record a successive approximation analog-to-digital converter (ADC) on the BalloonSat board convert the analog voltage signals from the sensors to bit-binary numbers suitable for storage in EEPROM memory. Each of these sensors require specific signal conditioning which is described below.

The cameras record their images on Secure Digital (SD) flash memory cards which are inserted into each respective camera. The images may be retrieved by connecting a USB cable between the camera and a computer or by removing the SD card from the camera and inserting it into a SD cardreader.

The BalloonSat, daughtercard, and batteries are all attached to a Styrofoam panel which slides into the payload capsule. The circuit cards are secured by machine screws to a plywood panel which is glued to the Styrofoam. The batteries are secured with Velcro® strips. The cameras attached to a separate plywood carrier which is secured by Velcro® strips to the camera port.

4.2.3 Control Electronics

The electronics necessary to control the sensors and cameras all reside on the daughtercard. Details of this circuitry follow. Components and designators referenced are shown in Figures 7 and 8 below.

Pressure SensorThe ICS1210 pressure sensor (PS1) is a Wheatstone bridge which requires a constant current excitation. An LM234 constant-current device (CS1) supplies the required 1.5 mA. Resistors R5, R6, and diode D1 form a temperature compensation network for this current source. The output of PS1 is a pair of voltages, whose difference (of order tens of millivolts) is proportional to absolute pressure. A differential amplifier is needed to condition the pressure signal. Operational amplifies U1, U2, and U3 form a differential input instrumentation amplifier whose voltage gain is approximately 27. Thus, the millivolt differential signal from the sensor is amplified to span the range 0-2.5 V for input to the ADC.

Exterior Temperature Sensor 1An Analog Devices AD22100 (TS1) is employed as the first exterior temperature sensor. This is a voltage-mode device whose output is an analog voltage is directly proportional to temperature. The voltage is nearly zero (0) at approximately -60 ˚C rising to approximately 2 V at 25 ˚C. Some amplification is needed to match this span to the 0-2.5 V input range of the ADC. Operational amplifier (U4) provides this needed amplification with a voltage gain of approximately 1.3.

Exterior Temperature Sensor 2A silicon PN-junction diode, 1N457 (TS2), is used as the second exterior temperature sensor. A silicon diode when forward-biased exhibits a voltage drop which is linearly proportional to temperature with a negative thermal coefficient of approximately 2.5 mV/˚C. In order to cover the temperature range -80 ˚C to 30 ˚C and provide a signal to the ADC in the range 0-2.5 V, it is necessary to both amplify the signal and subtract an offset voltage. A constant forward bias to TS2 is provided by voltage reference device U6, which also is also used to control the offset voltage. Operational amplifier U5 provides a voltage gain of approximately 8.5 and subtracts an



Figure 7

12

offset voltage controlled by potentiometer R16. The result is an output signal which is nearly zero at 30 ˚C rising to the ADC’s maximum input level of 2.5 V at approximately -90 ˚C.

Interior Temperature SensorTo monitor the temperature inside the payload capsule, the temperature sensor on the BalloonSat board is employed. The necessary amplification for signal conditioning is provided by an operational amplifier already present on the BalloonSat (U6 on BalloonSat schematic).

Camera ControlsTwo identical relay circuits (K1 and K2) are used to control the cameras. K1 has a pair of contacts, each of which controls the mode switch for one of the cameras. K2 also has a pair of contacts, each of which controls the shutter switch of one of the cameras. The relays are energized by applying a 5 V logic signal under control of the BASIC Stamp to switching transistors Q1 and Q2. Each relay circuit includes clamping diodes (D2 and D3) and transient-suppressing capacitors (C1 and C2) to minimize the possibility of voltage transients appearing on the BalloonSat 5 volt bus.

In order to turn-on each camera, it is necessary to pulse its respective mode switch four times followed by a single pulse of its shutter switch. Subsequently, a single pulse of the shutter switch takes a picture. The camera’s automatic power-down feature will not be activated if the camera takes at least one picture every 50 seconds. Under program control from the BalloonSat, each camera will take a picture every 15 seconds.

The cameras normally operate from a 1.5 V alkaline battery. Lithium batteries, however, are required for flight because low temperatures are expected. A suitable lithium battery, however, exhibits a terminal voltage of approximately 3 V at room temperature. Testing has revealed that cameras will operate satisfactorily with voltages in range 1.5V-2.5 V. In order to use the 3 V lithium cell to power the camera, a silicon diode is placed in series with the cell. Its voltage drop of a few tenths of a volt will reduce the voltage applied to the camera to an acceptable range. Because the lithium batteries powering the cameras are capable of supplying considerable current (several amperes) each battery is protected by a resettable fuse.


4.2.4 Power Supply

Figure 8 shows the power supply system for the payload. Main power for the BalloonSat, daughtercard, and camera relays is provided by two 6 V lithium photo batteries (Type 245, 1600 mAh). Each camera is powered by a single 3 V lithium cell (Type BR-C, 5000 mAh). Resettable fuses protect all battery packs. During laboratory development, power to the BalloonSat and daughtercard was provided by a Heathkit IP-2718 power supply. During development, camera power was supplied by a 1.5 V alkaline AA cell


Figure 8

Figure 8

14

4.2.5 Power Budget

Table 1 may be used to determine the required capacity for the main battery pack. Using the currents drawn and duty cycles for all devices supplied by the main battery (everything except the cameras) yields a required capacity of 300 mAh as shown below.

The Type 245 lithium batteries have more than adequate capacity even providing for degradation of performance at lower temperatures.

Repeating this procedure for each of the two cameras yields:

The BR-C lithium cells have more than adequate capacity.


Component Voltage(V) Current Draw(mA) Power (mW) Duty Cycle

%BalloonSat Subsystem 8 to 12 V 60 720 100

Data Archive On BalloonSat On BalloonSat On BalloonSat 100

Temperature Sensors 8 to 12 V 8 96 100

Pressure Sensor 8 to 12 V 5 60 100

Relays 5 V 24 120 3

Cameras (idling)each camera

2 V 200 400 85

Cameras (during exposure)each camera

2 V 320 640 15

Table 2

15

4.3 Software Design

4.3.1 Data Format & Storage

The data structure will consist of eight data values spanning nine bytes. The data archival system has a capacity of 16384 bytes which is sufficient to store 1820 data points. With a data acquisition frequency of one data point every 15 seconds, data may be stored for 27,300 seconds or 7.58 hours. We chose 15 seconds because at that rate the temperature changes 0.3 ˚C per measurement. That is about as close as we need for our experiment.

Table 3: Data StructureName BytesSequence No. 2Hour 1Minute 1Seconds 1Temperature Outside1 1Temperature Outside2 1Temperature Inside 1Pressure 1

Each photograph taken by the camera at its highest resolution requires approximately 160 kB of storage. The camera stores its pictures on a 512 MB Secure Digital card. The card provides enough storage capacity for approximately 3200 highest resolution images. At a photograph frequency of one picture every 15 seconds, the Secure Digital card has capacity to store pictures for 48,000 seconds more than 13.3 hours.

4.3.2 Flight Software

Refer to the Flight Software Flowchart in Figure 9. The program begins by initializing all of the variables and all of the constants and defining the input/output status of the Basic Stamp pins.

The program begins by reading the RTC RAM locations 4 and 5 to see if magic number ($DEAD, a hexadecimal value) is there. The presence of this magic number indicates that the preflight software initialized it and that this is the first time flight software has run. The program then reads the RTC and stores the launch time in the RTC RAM locations 2 and 3. It then clears out the magic number in locations 4 and 5 so that if the program happens to start over it will no that this is not the first time running.

Next the program initializes the sequence number 1. Then it inspects locations 0 and 1 on the RTC RAM to find an address on the EEPROM to which data can be written. Then starting at that address, the program examines memory in which it looks at the next ten addresses to see if data has been previously written. The pre-flight software initializes all memory location to hexadecimal FF. If something other than $FF is there, then it looks at the next ten addresses but if it is all $FF’s, then that’s where it will start writing.

The program then pulses the camera control relays in the correct sequence to power up the cameras, and waits for the RTC to read either 0, 15, 30, or 45 seconds. The program repeats the check of the next ten addresses to see if they are clear. If so, it will read the 4 ADC channels for


pressure, internal temperature, and the two outside temperatures, followed by a read of the RTC for the date, hour, minute, and second. All these data are written to the ten EEPROM



Figure 9

18

addresses and the last address that was written to is stored in locations 0 and 1 on the RTC RAM.

Next the program will then increment the sequence number and it will get the time of launch and calculate the mission elapsed time (MET). If MET is less than 4 hours then the program will take pictures and return to waiting for the 0, 15, 30, or 45 second mark on the RTC. If MET is greater than 4 hours, then the program will skip taking pictures and will jump directly to waiting for the 15 second intervals on the RTC.

The effect of program operation is that pictures are taken for four hours, the ADC data are taken until the memory is full, and the program will continue to execute until the power is pulled.

4.4 Thermal Design

The thermal environment is expected to cover the range of temperatures from 30 °C down to -70 °C and pressures from 1000 mbar down to 5 mbar. This is expected to provide a challenge for the Model 1210 pressure sensor which has a minimum rated temperature of -40 °C. It will also be a challenge for the temperature sensor whose minimum rated temperature is -50 °C. The temperature sensor is calibrated using dry ice to simulate the expected temperature of the tropopause. The insulation of the payload case is expected to keep the other sensors within their operating temperature range. We will know these exact results when we do a cold test and record the results.

4.5 Mechanical Design

4.5.1 External Structure

Top View Left Side View Right Side View


Figure 10 Figure 11 Figure 12

19

Top View Side View

The payload case is constructed of ¾” Foamular insulating sheathing from Owens Corning. It will form a hexagonal tube with a fixed end cap serving as its bottom lid and a removable end cap serving as its top lid. The interior is accessed by removing the top lid. A camera view port is attached to the front of the payload. There are 2 holes on the camera view port for the two cameras to give the camera a view of the outside. One hole is pointed directly outward and the other hold slight pointed slightly downward. The payload is attached to the balloon flight string by running the strings through holes running the length of the tube and the end caps through opposite vertices of the hexagon. There are no other external controls to the payload.

4.5.2 Internal Structure Top w/o BalloonSat Top w/ BalloonSat


Figure 13 Figure 14

Figure 15 Figure 16 20

We are going to build a small board out of the pink Foamular onto which we are able to screw the circuit board and the daughtercard. The board is able to slide into and out of the payload box easily for quick and easy access.

4.5.3 Weight Budget

The payload is limited to a nominal mass of 500 grams. The table at right details the masses of each component, as built. All masses were measured with an electronic balance which resolves 0.1 gram. Masses were rounded to the nearest gram.

The excess 77 grams (above the nominal 500 g) is due to the addition of the second digital camera and its associated battery. Should weight on the payload string become critical, removal of those extra components saves 70 g. However, the value of the extra camera, enhancing the field of view, is great enough to request a waiver of the weight ceiling.

.

5.0 Payload Development Plan

During the development phase for our payload, we tested all components of the system such as the electrical components, software, hardware, sensors, and interfacing components for proper functioning. Prototypes were made of the payload box to make sure that everything fit inside of the box. Prototype circuits were also put together on solderless breadboards. A prototype of the camera placement connection also was made to verify that the dimensions all line up correctly.

6.0 Payload Construction Plan

The Pacer payload is constructed using a material called Foamular. Foamular is a material that will function as the structure and also provide the insulation for the devices inside the payload. This type of material can withstand extreme temperatures, pressure and shock from the landing of the payload. The material that will reinforce the payload is silver mylar. Its properties are the ability to withstand cold temperatures and also work as a good insulator. A model crafter’s light-weight plywood was also added for support of the cameras in the camera port. The plywood is stuck together with the cameras using Gorilla Glue.

6.1 Hardware Fabrication and Testing

The sensors and their signal conditioning circuits are soldered to the daughtercard which is connected to the BalloonSat board. Two cameras are mounted to the side of the payload outside. They will receive power from battery packs inside the payload capsule. They are controlled by Team PACER-GSU FRR v1.3

Component Weight (g)

Case 172

Two Exterior Temperature Sensor

11

Pressure Sensor Included on daughtercard

Batteries for Camera 87

Batteries for BalloonSat 85

Two Cameras 73

BalloonSat and Daughtercard 149

Total 577Table 4

21

the BalloonSat through control circuits on the sensor auxiliary circuit board. The payload box will then be built to the specification mentioned. Then the other subsystem is tested to ensure they operate within specified parameters. Parts availability may delay the development to some extent. A drop test was performed to make sure that the box would stay intact and also that the program would still be taking data after impact with the ground. Calculations were made to get the specific height of a freely falling object to drop the payload box from knowing that it drops at a rate of 1300ft/min. So in our drop test, we dropped it from 7ft. and 3 in. to simulate the free-fall drop. The results of the test were that the box survived the drop only with a small crack in the side of it. Also data was still being taken so the test was successful.

6.2 Integration Plan

Sensors and interfaces circuits are wired to the BalloonSat’s ADC and digital inputs. The tests will determine whether the subsystems will operate collectively by conducting a cold test, a vacuum test and a shock test. The cameras signal and the sensors are connected to the BalloonSat board by way of ribbon cable and plug-in connectors. The batteries for the cameras are connected by the Anderson pole connector. The mechanical interface between the BalloonSat and the payload box is that the board will be mounted on a slab of Foamular which will slide straight done in the box.

6.3 Software Implementation and Verification

Many tests have been done to verify that that the software functions properly. Tests have been done to make sure that the system runs for 4 hours, that is takes pictures on time, that it stops taking pictures after for hours, and that the RTC reads the correct time. Also test we done to make sure that the RTC RAM kept information after the power was shut off, that the program will write all $FF’s to the EEPROM, and that the program reads out the information that was collected during a time period. Every 15 seconds sensor data is acquired and timestamps are written to the EEPROM in order they are received. A main loop is executed as long as power is connected to the BalloonSat circuit board.

6.4 Flight Certification Testing

6.4.1 Cold Soak Test

During the cold soak test, the flight program was initiated and the circuit board was place in the prototype box and placed it inside of a cooler filled with dry ice. The temperature went to -65°C and we let the program run in the ice chamber for 90 minutes. Our results were successful because out program was still taking data during the test. The camera was not included in the cold test because of limited quantity and if the camera had happened to get damaged there would not be an easy alternative.

6.4.2 Drop Test

During the drop test, the flight program was initiated and the circuit board was placed in the prototype box. Calculations were made to get the specific height of a freely falling object to drop the payload box from knowing that it drops at a rate of 1300ft/min. So the payload box was dropped from 7ft. and 3 in. to simulate the free-fall drop. The results of the test were that the


box survived the drop only with a small crack in the side of it. Also data was still being taken so the test was successful.

6.4.3 Pressure sensor calibration

The pressure sensor was placed inside of a vacuum chamber and wires ran out from the sensor to the computer to collect the data that it gathered. The pressure was measured by an ASHCROFT vacuum gauge. The test was successful because the graph that was plotted with the pressure against the ADC counts had a linear line of fit.

6.4.4 AD22100 & 1N457 Diode Temperature sensor calibration

The temperature sensors were tested by placing the two exterior temperatures by placing the both in a Brine Bath a taking data while in the water. The data points were plotted on a graph and it showed the PASCO Thermocouple Temperature versus the AD22100 ADC counts and the Diode ADC counts. The test results were successful because the sensors read the right temperature the whole time during testing.


Figure 17

23


Figure 18

24

6.4.5 Interior Temperature

The conditions of the flight are harsh due to strong winds, low temperatures and the low pressure that it will encounter. We will do thermal tests via dry ice to withstand the cold temperatures. Also we will do shock testing to verify if the payload box can withstand the fall. Finally we will do a vacuum test to see if the box can remain after encounters with low pressure down to 5 mB.

A specific calibration was not performed for the internal temperature sensor which resides on the BalloonSat board. Its output is specified to be approximately 560 mV at 25 ºC, rising at a rate of 1.9 mV/ ºC. The output of the sensor was measured as 0.569 V at 26 ºC and the output of the buffer amplifier was measured as 2.717 V, corresponding to a voltage gain of 4.78. The voltage appearing at the ADC input will therefore vary at a rate of (4.78) (1.9 mV/ ºC), or 9.1 mV/ ºC. The actual interior temperature may be calculated as below


Figure 19

25

7.0 Mission Operations

7.1 Pre-Launch Requirements and Operations

7.1.1 Calibrations

The temperature sensor must be calibrated. It is expected to encounter temperatures which are outside its rated range. The calibration must determine the sensors sensitivity to temperatures expected during the flight and the reproducibility of its measurements. The pressure sensor must be calibrated. The pressures expected during the flight are well within the rated range of the pressure sensor, but the ambient temperatures are not. The calibration must determine whether or not the pressure sensor is sufficiently insulated from ambient temperature to allow it to function. Calibrations are done prior to launch and verified after payload recovery.

7.1.2 Pre-Launch Checklist

Task Time Required (seconds)Attach the payload to the balloon flight string 300Insert fresh batteries into their designated locations. 10Attach a serial cable from a laptop computer. 3Boot the computer and start pre-launch software. 60Set the real time clock and initialize the EEPROM data archive system. 10Upload flight software. 30Disconnect the serial cable. 3Close and secure the payload lid. 10

7.2 Flight Requirements, Operations and Recovery

The flight is anticipated to ascend at the rate of 850 ft/min. until it reaches an altitude of 100,000 ft. The balloon is cut away from the payload string which will then fall back to Earth. A parachute will open and allow the payload string to descend at the rate of approximately 1300 ft/min.

This payload needs to reach the anticipated 100,000 ft. altitude. It requires no other services during flight.


7.3 Data Acquisition and Analysis Plan

7.3.1 Ground Software

Custom ground software is used to download the data from the EEPROM data archive. Microsoft Excel is used to transform the data text file into a column data file. Graphical Analysis is used to convert the data from numbers which fit the span of the BASIC Stamp’s analog-to-digital converter into standard units of temperature, pressure, and density.

7.3.2 Pre-Flight Software

The program begins by initializing all of the variables and all of the constants and defining the input/output status of the Basic Stamp pins.

The program begins by asking the user if they want to update the time in a debug window. If no is chosen then the current time is displayed in a debug window. If yes is chosen then the user will have to manually type in the correct minutes hours and date in a debug window to set the RTC. Next the program will initialize the RTC RAM locations 0 and 1 to 0. This is where the last EEPROM address that the flight software wrote a data record to (first byte of the record). When initialized to zero (0) this indicates that the EEPROM has been cleared is ready for storage at the first location of the EEPROM.

Next the program initializes locations 4 and 5 of the RTC RAM to a magic number. This magic number ($DEAD, a hexadecimal number) is an indication to the flight program that this is the first time that the flight software has ran since being initialized. The flight software will store the "launch time" of the hours and minutes in RTC RAM location 2 and 3.

After that the program will fill up the memory with $FF up to the location $FFFE in the EEPROM. The reason the program doesn’t fill it up to the maximum is to prevent the address from rolling over to zero.


Figure 20

27

Then pulses are sent to the camera relays to turn the cameras on. Next the program will initialize N (the number of times the program loops) to 0. Then the program will begin to read the time and date of the RTC, read the 4 ADC channels, and take pictures. All these data are displayed in a debug window to verify that it is working properly. The program will then increment N by 1 and ask itself if N is less than 10. If it is then the program will loop back to reading the values. If N is equal to ten then the program will stop. After all this id done, the program is initialized and ready for flight.

7.3.3Post-Flight Software:

We begin by initializing all of the variables and all of the constants and defining the input/output status of the Basic Stamp pins.

The program locates the first set that the values have been written to. It will begin to read the 9 consecutive bytes from the data on the EEPROM. The program will then display the sequence number and all of the data values in a debug window. The address will then be incremented and the program verifies is there is data there or not. If data is there then the program will loop back to reading the 9 data bytes from the EEPROM. If there is no more data then the program will then stop.

.

7.3.4 Data Analysis Plan

The data that we obtain is analyzed by placing all the numbers and recording into Microsoft Excel so that will we be able to place the information into the Graphical Analysis program. From there we make graphs of the data that we collected and begin to see the different trends of our information. We will use the ideal gas laws to figure out the density from the pressure and temperature data. Since all of our instruments are digital, the uncertainties should be 1 of the last decimal.


Figure 21

Figure 22

28

8.0 Project Management

Our group will have informal meetings during our workday only if necessary. If there is a problem with anything, then the dilemma is announced one day in advance of the meeting so we can decide upon the time we should all be present. After all meetings, we will document any changes made to the project. 8.1 Organization and Responsibilities

Johnte Bass Herman Neal Matthew WareTelephone (404) 643 6003 (870) 866 0132 (318) 497 3475Email [email protected] [email protected] [email protected] Software/Programming Engineering Testing/Calibration/Quality

Control

Each person will have administrative responsibility for his area. Because they will work in close proximity, they will monitor each other’s progress. The delegation’s work is in close collaboration. Attempts are made to reach a consensus on all design decisions. In the event of a conflict which cannot be resolved, a vote is taken to resolve the issue.

8.2 Configuration Management Plan

Designs and progress is documented in a journal. If a design change may conflict with other parts of the payload, the change is discussed among the group. The people who are in charge of the conflicted pieces are considered the authority. If, for some reason, a compromise cannot be reached, there is a vote to pick the course of action. In event of a change in the FRR, the change is recorded on Page ii of the FRR.

8.3 Interface Control

In the event that an interface has changed, it is documented in a journal and/or recorded on page ii of the FRR. Then it will also be brought to the attention of the other group members.


Table 5

29

mailto:[email protected]

ID Task Name Duration Start Finish1 Power System 8 days Mon 7/16/07 Wed 7/25/07

2 Parts 1 day Mon 7/16/07 Mon 7/16/07

3 QA/ QC 8 days Mon 7/16/07 Wed 7/25/07

4 Build 1 day Tue 7/17/07 Tue 7/17/07

5 Test 4 days Fri 7/20/07 Wed 7/25/07

6 Sensor System 8 days Mon 7/16/07 Wed 7/25/07

7 Pressure Sensor 8 days Mon 7/16/07 Wed 7/25/07

8 Constant Current Source Assembly 1 day Mon 7/16/07 Mon 7/16/07

9 Constant Current Test 1 day Mon 7/16/07 Mon 7/16/07

10 Pressure Sensor Calibration 1 day Tue 7/17/07 Tue 7/17/07

11 Signal Conditioning Assembly 1 day Wed 7/18/07 Wed 7/18/07

12 Signal Conditioning Test 1 day Thu 7/19/07 Thu 7/19/07

13 Pressure Sensor System Assembly 1 day Thu 7/19/07 Thu 7/19/07

14 Pressure Sensor System Testing 4 days Fri 7/20/07 Wed 7/25/07

15 Inside Temperature Sensor 1 day Mon 7/23/07 Mon 7/23/07

16 Calibration 1 day Mon 7/23/07 Mon 7/23/07

17 Outside Temperature Sensor #1 4 days Mon 7/16/07 Thu 7/19/07

18 Parts 1 day Mon 7/16/07 Mon 7/16/07

19 Characterizaton 1 day Wed 7/18/07 Wed 7/18/07

20 Assembly 1 day Thu 7/19/07 Thu 7/19/07

21 Testing 1 day Thu 7/19/07 Thu 7/19/07

22 Outside Temperature Sensor #2 3 days Tue 7/17/07 Thu 7/19/07

23 Parts 1 day Tue 7/17/07 Tue 7/17/07

24 Characterizaton 1 day Wed 7/18/07 Wed 7/18/07

25 Assembly 1 day Thu 7/19/07 Thu 7/19/07


27 Cameras A and B 4 days Mon 7/16/07 Thu 7/19/07

28 Software 1 day Mon 7/16/07 Mon 7/16/07

29 Payload Mount Design 1 day Mon 7/16/07 Mon 7/16/07

30 Payload Mount Build 1 day Tue 7/17/07 Tue 7/17/07

31 Control and Power Circuit Design 1 day Mon 7/16/07 Mon 7/16/07

32 Control and Power Circuit Build 1 day Tue 7/17/07 Tue 7/17/07

33 Assembly 2 days Wed 7/18/07 Thu 7/19/07


35 Sensor Subsystem Integration 1 day Thu 7/19/07 Thu 7/19/07

36 Sensor Subsystem Testing 1 day Fri 7/20/07 Fri 7/20/07

37 BalloonSat System 9 days Tue 7/17/07 Fri 7/27/07

38 Software 2 days Tue 7/17/07 Wed 7/18/07

39 Test 6 days Fri 7/20/07 Fri 7/27/07

W T F S S M T W T F S S M T W T F S S M T W T F S S M T W T F S S M T W T F S S MJun 24, '07 Jul 1, '07 Jul 8, '07 Jul 15, '07 Jul 22, '07 Jul 29, '07 Aug 5, '07

ID Task Name Duration Start Finish38 Software 2 days Tue 7/17/07 Wed 7/18/07

39 Test 6 days Fri 7/20/07 Fri 7/27/07

40 Data Archive System 10 days Mon 7/16/07 Fri 7/27/07

41 Parts 1 day Mon 7/16/07 Mon 7/16/07

42 Software 1 day Tue 7/17/07 Tue 7/17/07

43 QA/ QC 9 days Tue 7/17/07 Fri 7/27/07

44 Test 6 days Fri 7/20/07 Fri 7/27/07

45 Ground Support System 12 days Tue 7/17/07 Wed 8/1/07

46 Components 1 day Tue 7/17/07 Tue 7/17/07

47 Laptop Computer 1 day Tue 7/17/07 Tue 7/17/07

48 RS-232 Cable for BalloonSat 1 day Tue 7/17/07 Tue 7/17/07

49 USB Cable for Cameras A and B 1 day Tue 7/17/07 Tue 7/17/07

50 QA/ QC 10 days Tue 7/17/07 Mon 7/30/07

51 Test 6 days Fri 7/20/07 Fri 7/27/07

52 Software 12 days Tue 7/17/07 Wed 8/1/07

53 BASIC Stamp Editor 8 days Fri 7/20/07 Tue 7/31/07

54 Custom Data Download Program 11 days Tue 7/17/07 Tue 7/31/07

55 Custom Excel Spreadsheet 10 days Wed 7/18/07 Tue 7/31/07

56 GraphicConverter 7 days Mon 7/23/07 Tue 7/31/07

57 Graphical Analysis 7 days Tue 7/24/07 Wed 8/1/07

58 PowerPoint 6 days Wed 7/25/07 Wed 8/1/07

59 QuickTime Pro 7 days Tue 7/24/07 Wed 8/1/07

60 Term232 8 days Fri 7/20/07 Tue 7/31/07

61 Vizio 1 day Tue 7/31/07 Tue 7/31/07

62 Test 7 days Fri 7/20/07 Mon 7/30/07

63 Mechanical Sysytem 9 days Mon 7/16/07 Thu 7/26/07

64 Parts 1 day Mon 7/16/07 Mon 7/16/07

65 QA/ QC 9 days Mon 7/16/07 Thu 7/26/07

66 Build 2 days Mon 7/16/07 Tue 7/17/07

67 Test 4 days Fri 7/20/07 Wed 7/25/07

68 Thermal System 9 days Mon 7/16/07 Thu 7/26/07

69 Parts 1 day Mon 7/16/07 Mon 7/16/07

70 QA/ QC 9 days Mon 7/16/07 Thu 7/26/07

71 Build 2 days Mon 7/16/07 Tue 7/17/07

72 Test 4 days Fri 7/20/07 Wed 7/25/07

73 Management 27 days Mon 6/25/07 Tue 7/31/07

74 Documents 27 days Mon 6/25/07 Tue 7/31/07

75 PDR 5 days Mon 6/25/07 Fri 6/29/07

76 CDR 9 days Thu 7/5/07 Tue 7/17/07


ID Task Name Duration Start Finish77 FRR 10 days Mon 7/16/07 Fri 7/27/07

78 Science Presentation 3 days Fri 7/27/07 Tue 7/31/07

79 Configuration Control 12 days Mon 7/16/07 Tue 7/31/07

80 Record Changes to CDR 12 days Mon 7/16/07 Tue 7/31/07

81 Email Notifications of Changes to CDR12 days Mon 7/16/07 Tue 7/31/07

82 Integration 4 days Thu 7/19/07 Tue 7/24/07

83 Electronic 1 day Thu 7/19/07 Thu 7/19/07

84 Mechanical 1 day Thu 7/19/07 Thu 7/19/07

85 Thermal 1 day Thu 7/19/07 Thu 7/19/07

86 Calibration 3 days Fri 7/20/07 Tue 7/24/07

87 System Testing 3 days Fri 7/20/07 Tue 7/24/07

88 Vacuum Testing 1 day Fri 7/20/07 Fri 7/20/07

89 Pressure Sensor Calibration 1 day Fri 7/20/07 Fri 7/20/07

90 Cold Testing 1 day Mon 7/23/07 Mon 7/23/07

91 Temperature Sensor Calibrations 1 day Mon 7/23/07 Mon 7/23/07

92 Shock Testing 1 day Tue 7/24/07 Tue 7/24/07

93 Flight Operations 2 days Mon 7/30/07 Tue 7/31/07

94 Prelaunch 2 days Mon 7/30/07 Tue 7/31/07

95 Flight Tracking 1 day Tue 7/31/07 Tue 7/31/07

96 Balloon Recovery 1 day Tue 7/31/07 Tue 7/31/07

97 Risk Management Plan 3 days Tue 7/10/07 Thu 7/12/07

98 Brainstorming 1 day Tue 7/10/07 Tue 7/10/07

99 Evaluate 1 day Wed 7/11/07 Wed 7/11/07

100 Matrix 1 day Wed 7/11/07 Wed 7/11/07

101 Risk Management Plan 1 day Thu 7/12/07 Thu 7/12/07


9.0 Master Schedule

9.1 Work Breakdown Structure


Figure 23

30

9.2 Staffing Plan

Johnte Bass – Software Design, Debugging, Documentation, IntegrationHerman Neal – Documentation, Mechanical Design, Thermal Design, Electrical Design, Testing, IntegrationMatthew Ware – Team Management, Documentation, Calibrations, Testing, Integration

9.3 Timeline and Milestones

PDR – June 29 CDR – July 13Mechanical/Thermal Build – July 20 Electrical Build – July 20Integration – July 19Testing – July 25FRR – July 26Flight – July 31Science Presentation – August 1

10.0 Master Budget

10.1 Expenditure PlanBatteries (Li) TBD

BallonSat On hand

Resistors(series) On hand

Transistors On hand

Foamular On hand

Reserve Fund (20%) $100.

Total Budget $500.


Table 6

31

10.2 Material Acquisition PlanBatteries (Li) On hand

BallonSat Fabricated

Resistors(series) On hand

Transistors On hand

Foamular On hand

11.0 Risk Management and Contingency

Risk Event When Trigger Contingency PlanMissing Deadlines Throughout Behind Schedule Meet more often/ longerElectrical Issues Development/ Integration Fails Tests PrototypingThermal Issues Development/ Integration Fails Tests PrototypingCamera Malfunction Flight No pictures PrototypingExceeding Money Budget Development Expenses exceed $500 Use reserve fundExceeding Power Budget Development Exceeding amp/hrs PrototypingReceive Components Late Development When component arrives

lateOrder earlier

Power Failure Development/ Integration Fails Tests PrototypingSoftware Issues Development/ Integration Fails Tests PrototypingMechanical Issues Development/ Integration Fails Tests Prototyping


54 Missing

Deadlines3 Electrical

Issues2 Thermal Issue Camera

Malfunction1 Exceeding

Money Budget/ Power Budget

Exceeding Weight Budget

Ordered components don’t arrive/ Power Failure

Software Issues

Mechanical Issues

1 2 3 4 5

Likelihood

Impact

Table 7

Table 8

Table 9

32

12.0 Glossary

PACER Physics & Aerospace Catalyst Experiences in ResearchCDR Critical Design ReviewFRR Flight Readiness ReviewTBD To be determinedTBS To be suppliedEEPROM BalloonSat’s internal memoryADC Analog to Digital Converter
