LA ACES Program
Preliminary Design Review Document
for the
Operation Ozone
Experiment
by
Team
UNO
Prepared by:
Christopher Barber
Date
Donald Swart
Date
Gregg Ridlon
Date
Robert Schefferstein
Date
Michael O’Leary
Date
Larry Blanchard
Date
Institution Signoff (replace with name)
Date
LA SPACE Signoff
Date
Submitted:
Reviewed:
Revised:
Approved:
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Change Information Page
Title: PDR Document for Operation Ozone
Date: 02/22/2005
List of Affected Pages
Page Number
Team UNO
Issue
Add Section 3.2, 4.6
Change 3.2 to 3.3 (Technical Goals)
Change 2.0, 3.0, 3.3, 4.0 – 4.2, 4.4, 4.5
Change 5.0, 6.0, 7.1, 8.1, 9.0, 9.2, 10.0
ii
Date
19 Mar 05
19 Mar 05
21 Mar 05
23 Mar 05
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Status of TBDs
TBD
Section
Number
4.4
6.1
7.3
Team UNO
Description
Thermal System performance
Sampling rate and packet size
Data Analysis Algorithm
iii
Date
Date
Created Resolved
1 Apr 05
5 Apr 05
25 Mar 05
PDR v2.0
TABLE OF CONTENTS
Cover ............................................................................................................................................. i
Change Information Page ............................................................................................................ ii
Status of TBDs ............................................................................................................................ iii
Table of Contents ........................................................................................................................ iv
List of Figures and Tables.............................................................................................................v
1.0 Document Purpose ..................................................................................................................1
1.1 Document Scope ...............................................................................................................1
1.2 Change Control and Update Procedures ...........................................................................1
2.0 Reference Documents .............................................................................................................1
3.0 Mission Objectives..................................................................................................................1
3.1 Science Goals ....................................................................................................................2
3.2 Science Background..........................................................................................................2
3.3 Technical Goals ................................................................................................................3
4.0 Payload Design .......................................................................................................................4
4.1 Principle of Operation .......................................................................................................4
4.2 System Design ..................................................................................................................4
4.3 Electrical Design ...............................................................................................................6
4.4 Thermal Design .................................................................................................................7
4.5 Mechanical Design............................................................................................................8
4.6 Power Budget ....................................................................................................................8
5.0 Payload Development Plan ...................................................................................................10
6.0 Hardware Fabrication and Testing ........................................................................................10
6.1 Integration Plan ...............................................................................................................11
6.2 Software Implementation and Verification .....................................................................11
6.3 Flight Certification Testing .............................................................................................12
7.0 Launch Requirements ...........................................................................................................12
7.1 Flight Requirements and Operations ..............................................................................12
7.2 Data Acquisition and Analysis Plan ...............................................................................12
8.0 Project Management .............................................................................................................11
8.1 Interface Control .............................................................................................................13
9.0 Master Schedule ....................................................................................................................14
9.1 Staffing Plan....................................................................................................................14
9.2 Timeline and Milestones .................................................................................................15
10.0 Master Budget .....................................................................................................................16
10.1 Material Acquisition Plan .............................................................................................16
11.0 Risk Management and Contingency ...................................................................................16
12.0 Glossary .............................................................................................................................19
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LIST OF FIGURES
1. Absorption Cross Sections in the Atmosphere .........................................................................2
2. Ozone Density as a function of Altitude ...................................................................................3
3. Summing Circuit Diagram ........................................................................................................6
4. Discharge Curve under constant resistance ..............................................................................7
5. Heater Circuit Diagram .............................................................................................................7
6. Discharge Curve under constant current ...................................................................................9
7. Rate Sensitivity under continuous current at different temperatures ........................................9
LIST OF TABLES
1. List of Systems ..........................................................................................................................4
2. Table of Interfaces ....................................................................................................................6
3. Weight Budget ..........................................................................................................................8
4. Power Budget ............................................................................................................................8
5. Work breakdown structure ......................................................................................................14
6. Project Timeline ......................................................................................................................15
7. Project budget .........................................................................................................................16
8. Risk Matrix .............................................................................................................................18
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1.0 Document Purpose
This document describes the preliminary design for the Operation Ozone experiment by Team
UNO for the ACES Program. It fulfills part of the LA ACES Project requirements for the
Preliminary Design Review (PDR) to be held April 9, 2005.
1.1 Document Scope
This PDR document specifies the scientific purpose and requirements for the Operation Ozone
experiment and provides a guideline for the development, operation, and cost of this payload
under the La ACES Project. 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 is discussed. Finally, the
designs and plans presented here are preliminary and will be finalized at the time of the Critical
Design Review (CDR).
1.2 Change Control and Update Procedures
Changes to this PDR document shall only be made after approval by designated representatives
from Team UNO and the La ACES Institution Representative. Document change requests
should be sent to Team members and the La ACES Institution Representative and the La ACES
Project.
2.0 Reference Documents
Jacobson, Mark Z; Atmospheric Pollution; Copyright 2002; Cambridge University Press
http://en.wikipedia.org/wiki/Ultraviolet
Solar Radiation Research Laboratory
http://www.nrel.gov/midc/srrl_bms/
Equations
http://scienceworld.wolfram.com/physics/
Absorptional Cross Sections
http://www.heliosat3.de/e-learning/radiative-transfer/rt1/AT622_section10.pdf
3.0 Mission Objectives
Our objective is to measure ozone thickness as a function of altitude. Measurements will be
derived from the measurable quantities of UV intensity and temperature.
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3.1 Science Goals
Our main goal is to measure UVB and UVC irradiance as it is transmitted through the ozone
layer, in order to determine the relative thickness of the ozone layer as a function of height above
the surface. Then we will correlating this data to Fig. 2, as an approximation for what we have
measured. We predict that our data of the relative thickness of ozone will be within ±10 DU as a
function of height above the ground.
3.2 Science Background
Radiation at wavelengths less than 4000 Å correspond to ultraviolet radiation which accounts for
about 7% of total solar radiation. When discussing ozone, we are concerned with radiation in the
ultraviolet region of the electromagnetic spectrum. Ultraviolet radiation is divided in to three
spectral types: UVA, UVB, and UVC. UVA falls right below visible light; with wavelengths that
vary from 3200 to 4000 Å. Ozone is totally transparent to UVA radiation and due to its low
energy will not be absorbed. UVB radiation, which ranges in wavelength from 2800 to 3200 Å,
is partially absorbed by ozone concentrations and is more energetic than UVA thought it is
harmful to the biosphere. Fortunately, it exists in lesser amounts and is largely absorbed by
ozone. UVC, at 2000 to 2800 Å, which is the most energetic and most damaging but least
prevalent of the UV radiation types, is totally absorbed by ozone and normal diatomic oxygen
high in the atmosphere.
Figure 1 - Absorption properties of various compounds in the atmosphere
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Ozone is most effective at absorbing radiation at the 2500Å wavelength. In fact, it is 100 times
more efficient at 2500Å than it is at 3500Å. After ozone absorbs radiation at this wavelength it
reradiates it at longer wavelengths as an isotropic source into the atmosphere.
When considering UV radiation at the altitudes that we will be flying one of our concerns is how
much UV is absorbed at altitudes greater than the balloons burst altitude. With burst altitude
being approximately 33km and knowing that the ozone layer extents above 50km we will have to
make approximations for thickness levels and transmissions properties from. The density of the
ozone varies with altitude and at about 30km our payload will be well over ½ to ⅔ of the ozone
layer. That will mean that the only sources of UV reduction will be the small portion of ozone
still above our payload.
Research shows that molecular oxygen (O2)
absorbs much of the lower wavelengths of UV,
wavelengths between 1000Å and 2400Å. This is
one of the major reasons that ozone exists
primarily at upper altitudes. Molecular oxygen
absorbs the high energy radiation, which causes it
to dissociate into atomic oxygen, and upon
emitting the light again its energy is reduced as a
result and has a longer wavelength. Atomic
oxygen is highly reactive and therefore it spends
very little time in this state before recombining
with another molecule of oxygen to form ozone.
As a whole, the atmosphere contains a myriad of
gases that absorb an equally wide variety of light
wavelengths; however, the only molecule that
absorbs a significant amount of UV light (>.01%)
through our wavelength range is O3.
Figure 2 – Ozone Density
Measuring the amount of UV irradiance, especially within the range of ozone where it is most
absorbent, we will have a crude method of measuring the relative thickness of the ozone layer.
The unit used in measuring the thickness of the ozone layer is the Dobson Unit (DU), which is
equal to a one column of ozone .01mm thick at STP.
3.3 Technical Goals
In order to meet the science goals we have outlined we will need to be able to put together an
effective method to measure UV radiation that can easily be correlated into flux levels. We will
be exposing an array of photodiodes to the incident flux at our payload’s given altitude. The
high altitude will require a thermal source in order to keep the payload components from
dropping below operating temperatures. The low pressure will mean that the payload will need
to be able to vent and that our thermal control is effective using only radiation and conduction.
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4.0 Payload Design
The sensory unit is an array of 4 photodiodes that are sensitive to a very specific wavelength
band of UV light. The output of these diodes will be conditioned through a summing circuit to a
single channel on the BalloonSAT. This output will then interface with the analog-to-digital
converter on the BalloonSAT which will also record the information in EEPROM.
To compliment our UV readings we will include an external and an internal temperature
measurement, as well as a pressure sensor. External temperature and pressure will be measured
and recorded by the HOBO data collection unit, and the internal temperature will be measured
and recorded by the BalloonSAT in order to facilitate activation of the heating unit at low
internal temperatures.
4.1 Principle of Operation
UV detection system: This system’s goal is to collect digital data of UV intensity in a specific
wavelength range which will then be correlated to effective ozone coverage. The sensors’
wavelength range is 2250 Å to 3200 Å with peak sensitivity at 2800 Å.
Data acquisition system:
UV acquisition: Four photodiodes will provide a signal to a summing circuit which will
collect and condition the analog signal sent to an ADC, which will then be sent to the
BASIC stamp for processing and storage.
Temperature acquisition: HOBO unit will measure the external temperature; BalloonSAT
will measure internal temperature.
Pressure acquisition: HOBO will record and measure pressure.
Temperature regulation system: A lightweight industrial battery will power a small resistor
array to provide heat throughout the flight. Its activation will be regulated by the
BalloonSAT based on internal temperature measurements.
4.2 System Design
List of Systems
UV Detection
Controller
Pressure Detection
Temperature Detection
Temperature Regulation
Power
Mechanical
Table 1 – Systems
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Description of Major Systems:
UV Detection System – This system will detect ultraviolet radiation throughout our flight from
0 to 30 km. It is composed of two subsystems
Subsystems:
Photodiodes – Four photodiodes filtered to detect ultraviolet light in the wavelength
range of 2250 to 3200 Å. The peak sensitivity is at 2800 Å which is close to the peak absorption
wavelength of 2500 Å for ozone. This will yield more accurate results in determining the
amount of ozone present between the sun and the payload. The photodiodes will be arrayed
evenly around the payload exterior, one per side.
DCU – The BalloonSAT will be the controller for the UV detection system. It will
process and store all data received by the photodiodes in memory on board.
Controller System – The BASIC stamp will be the controlling unit of the BalloonSAT, and
therefore of the entire payload. It will store programming and execute its commands when
conditions for each are met. Its programming will be uploaded prior to flight.
Power System – One 9V battery will be used to power the BalloonSAT and its major
components. The battery’s capacity is 1200 mAh, reduced to approximately 600 mAh at 273K.
A second battery of the same model will be used to separately power the thermal system.
Pressure Detection System – A pressure transducer with a measurement range of 0 to 15 PSIA
will be included so that pressure measurements can be included with every time stamp. The
transducer will be controlled, processed and stored by the BASIC stamp.
Temperature Detection System – In order to regulate core temperature as well as monitor
exterior temperature two different subsystems will be utilized.
Subsystems
External Temperature: The external temperature reading will be taken by a
thermocouple that is fed directly into the HOBO for processing and storage. It will be exposed
to the external environment through the base of the payload, slightly depressed so that it remains
out of the direct radiation of the sun. This will make sure our temperature reading is that of the
atmosphere and not that of the solar heated thermocouple.
Internal: The BalloonSAT has an onboard temperature sensor that will take readings of
the internal temperature of the payload. This will be useful in two ways. It allows the
BalloonSAT to regulate to the thermal system by controlling power to the heater at the
designated temperatures via a relay in order to conserve the heating system’s battery life. It will
also allow us to know if our payload experienced any extreme temperatures that could possibly
cause erratic readings or other malfunctions.
Temperature Regulation System: A 9V battery of the same model used to power the
BalloonSAT will be used to provide power to a 12Ω resistor array in order to produce heat. The
heat will be distributed to the other internal components primarily through conduction
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Mechanical System – A foam board box will be constructed to house an inner construct that will
hold all components in place during flight. This inner construct serves to both protect the
payload from damage and to hold all inner components securely in place so that they can be
placed in very close proximity and minimize the distance heat must radiate to maximize heating
efficiency. The outer shell will be insulated with polystyrene to better retain heat and will be
covered by reflective tape to prevent overheating due to radiation absorption.
System Interfaces:
UV Detection System: all photodiodes interface to the BASIC Stamp through a summing
amplifier circuit.
Power System: 1 9V battery provides power to the circuit systems; physical interface with
thermal system keeps temperature at optimum.
Thermal System: BalloonSAT will detect temperature and activate heater at 273K
All Systems: Physical interfacing will keep boards and components within operating ranges.
No other systems physically interface.
Table 2 – Interfaces
4.3 Electrical Design
The photodiode signal conditioning
circuit is intended to amplify the
output of the photodiode to a
readable analog voltage signal which
is then algebraically summed and
can be measured by the ADC
included on the BalloonSAT board.
Capacitor values for C1 through C4
of 5660 pF shown in the schematic
were provided by the Op Amp
manufacturer’s circuit calculator, the
capacitors serve the purpose of
compensating the reverse junction
capacitance of the photodiode and
the input capacitance of the Op
Amp(s). Similarly, the resistors R1,
R3, R5, and R7 in the circuit control
the Op amplifiers (U1 – U4) output
gain. The 100 K Ohm resistors (R2,
R4, R6, R8, and R9) bias the
summing Op Amp (U5) to produce a
gain factor of 1:1. The actual values
Figure 3 – Summing Circuit
of both resistance and capacitance
are subject to modification to adjust output
to ideal gain with our actual circuit. The combined summing-amplifier
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circuit is intended to operate from the regulated five volt power bus of the BalloonSAT, thereby
simplifying construction as well as avoiding additional mass of a discrete power supply and
regulation system.
4.4 Thermal Design
The thermal environment that
Operation Ozone expects to
encounter is 223K through
298K. The thermal operating
ranges for the major
components are as follows:
Battery – 233K-348K;
Photodiodes – 248K-348K;
HOBO – 253K-348K.
The temperature control system
will consist of low mass
battery/resistor array that will
be activated by the Balloon
SAT when internal
temperatures reach 273K or
lower. The advantage to the
battery and resister array is its
ability to be activated in flight
to prevent premature power
usage and its ability to rapidly
heat to 338K from 293K and
slowly return to 293K over a
period of 2 hours. The
schematic diagram for the
heating system follows:
Figure 4 – Discharge Curve under constant resistance
Heat will be distributed though
the payload primarily through
conduction. The
heating array will be placed
in immediate contact with
power supply for the
BalloonSAT to keep the
Figure 5 – Heater Circuit
battery at an optimum
operating temperature. A
heat sink will be attached to the heating elements to distribute the heat to the BalloonSAT
components.
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4.5 Mechanical Design
The payload mechanical design will be a cube approximately 15 cm to a side. This size is
optimum allowing sufficient space for electronics as well as the insulation. Keeping it as small
as possible will reduce the surface area resulting in slower radiation of heat away from the
payload. Also the padding of essential parts on the interior (mostly data storage units) will also
be key.
A removable construct will be used to house the internal
components. A shelf of foam board 10 cm by 12.5 cm with a
6.25 cm by 5cm hole in the center will hold the BalloonSAT. A
lidless box of dimensions 6.25 cm by 5 cm and 5 cm tall will
house the HOBO, batteries, and heating element. The box will
be sized to fit snuggly into the BalloonSAT shelf in order to keep
all components close to the heat source to maximize heat
distribution by conduction and radiation.
Weight Considerations:
The weight constraint is 500g with a 10% margin for error. At
this time we are working with a 450g allowance and 50g back up
in the event that original figures and estimates are incorrect.
Weight Breakdown:
Mass
(g)
Component
Box
Photodiodes
HOBO
Thermocouple
Pressure
Transducer
Battery
BalloonSAT
Thermal System
TOTAL
141
16
15
15
15
35
75
60
372
Table 3 – Weight Budget
4.6 Power Budget
Our payload will operate on one 9V, 1200 mAh battery that is capable of operating in
temperatures as low as 233K. The battery will be capable of operating for about 20 hours at a
constant drain of 60mA and 293K. At our planed internal temperature of 273K it will be capable
of generating 600 mAh of current which will sustain our payload for approximately 10 hours.
Component
BalloonSAT
OpAmp x 4
Summing Circuit
Total
Draw (mAh)
20
20 (est)
20 (est)
4 Hour total
80
80
80
60 mAh
240 mAh
Table 4 – Power Budget
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Figure 6 – Discharge Curve under constant current
Figure 7 – Rate Sensitivity under continuous current at
different temperatures
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5.0 Payload Development Plan
The preliminary design of the payload involves a balance of UV collection and sensor
sensitivity. Initially we had thought to use fiber optics to channel light to the payload interior but
because of the uncertainty of the light transmission and interference we abandoned the idea in
favor of simply using four photodiodes, each to a side, with peak sensitivity at 2800 Å. The
wavelength range is optimum for measuring the wavelengths most absorbed by ozone which will
relate more directly to ozone cover.
Prior to payload fabrication we will be testing various materials for box construction in order to
determine what will give us a good balance of shock absorption, thermal maintenance, and
overall strength. A method to have easy access to the interior without sacrificing thermal
maintenance will also be devised.
6.0 Hardware Fabrication and Testing
Electronics: The BalloonSAT itself is already constructed, however there are many components
left to be added to the board. The photodiode array and its op amps will be mounted directly to
the board in the open area for addition circuitry. The photodiodes will be connected by adapters
that allow them to be added and removed as needed so that the BalloonSAT can still be removed
from the payload without needing to ruin the payload shell. Until the photodiodes are received
we will conduct tests for the radiation array using ordinary off the shelf photodiodes. Once the
UV photodiodes are received they will be integrated, tested, and calibrated. Additionally, a
pressure transducer will be mounted and routed through the BASIC stamp. The HOBO is a
completely self reliant piece of equipment that will be measuring external temperatures using an
attachable thermocouple.
Thermal testing: Once the electronics are completed and functional they will be placed in
the outer shell and insulation and then immersed in a dry ice chest that will simulate conditions
at 30km altitude. To ensure no unnecessary damage to electronics immersion will be for short
durations and then successively lengthened until we are sure it will last for approximately 2
hours below 273K. Simultaneously we will be testing the HOBO thermocouple so we will know
the temperature within the dry ice chest.
Impact testing: The payload will be dropped from progressively greater heights and
checked for proper functioning after each fall until it is dropped from about 12 feet and still
functions. If any indication of needing improvement is evident the test will be halted and the
shock absorption will be improved before continuing.
Calibration: In order to calibrate and scale the photodiodes mercury lamps will be placed
a specified distance away to emit a known wavelength and test the voltage output by the
photodiodes within its range of sensitivity. This will require only that the photodiode circuit is
assembled and that the data storage program is completed.
Vacuum: The pressure transducer will be subjected to a near vacuum in a chamber in
order to scale the voltage outputs correctly.
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Heater: The heater will be constructed using a series of resistors that will radiate heat as current
passes through them.
Thermal testing: The first phase of testing was to assess the ability of the array to rapidly
rise in temperature. This test was done at room temperature (approx 298K) in order to have an
idea of the unit’s necessary response time when temperature begins to fall. Based on our initial
test and data we will program the BalloonSAT to activate the heater when internal temperatures
are 283K and continue to heat the unit until it reaches 293K at which point the heater will be
turned off to conserve battery power.
Outer shell/Insulation: The outer shell is constructed using foam board cut to have an interior
cavity with dimensions of 15 cm to a side. Polystyrene will be used to insulate the shell interior.
Thermal testing: The shell and insulation will be immersed in dry ice along with the
heater to test the ability of the system to generate and retain heat in a cold environment. The
goal is a successful submersion of 2 hours or more with out dropping below 273K. In order to
facilitate keeping the thermal unit battery alive long enough to make a long length submersion
the spare BalloonSAT with the heater activation program will be integrated to the test
Impact testing: This test will follow the same guidelines for the drop test with the
electronics.
6.1 Integration Plan
Subsystems will be entirely contained within the mechanical system, directly connected to allow
good thermal conduction. The UV detection subsystem will be routed through the BalloonSAT
by physically being a part of the circuit board and directly routed to the BASIC stamp.
The HOBO will be self contained and will control the pressure transducer and the external
thermocouple. The HOBO will be removed from its casing, for mass regulation, and then it will
be placed in contact with the thermal system in order to keep it within operating temperatures
A separate circuit board will be constructed for the thermal system but it will also be routed to
the BalloonSAT circuitry so that it may be controlled by the BASIC stamp. It will be in physical
contact will all components either through direct contact or through indirect contact, such as
aluminum (or other similar heat conducting metal) strips.
The external thermocouple will protrude from the base of the payload so that it can detect
external temperature with as little interference from the sun’s radiation as possible. Similarly,
each photodiode will be exposed from each size so that it may receive as much of the sun’s
radiation as it can.
6.2 Software Implementation and Verification
Flight software will be divided into collection and retrieval stages. Only the collection portion
will be included in-flight, and this will allow us to use one switch to signal when collection or
retrieval should be started.
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Before flight stored memory will be zero and the collection program will be stored on the
BalloonSat. When ready a switch will be turned on signaling the BalloonSat to begin storing
data. During flight an infinite run loop will collect data and store it in packet form, then a system
pause defined by packet size and available space. The packet’s data will be defined as a
timestamp followed output from each sensor. At the end, the last packet will be designated as an
End Of File marker (EOF) that will be moved with each new packet.
In case of an unexpected shutdown during flight the BalloonSat will have instructions to operate
a start up process that will reset the current file marker to the EOF and make a check that the last
packet was complete. If the last packet was incomplete a marker will be placed to an
interruption and the collection will continue.
After flight the switch will be moved to the off position and a new run program will be stored
instructing the BalloonSat to output all data to an external file, which will be formatted according
to the same packet structure we defined for collection.
6.3 Flight Certification Testing
During the flight temperatures are expected to reach approximately 223 K and pressure will drop
to about 5 mb. We will test the payload for these expected conditions by super cooling the test
payload in an vacuum chamber surrounded by dry ice. The vacuum chamber will simulate the
low pressures while the dry ice will help simulate the low temperature at altitude. The
importance of doing both tests together is primarily to assure that the only methods of heat
distribution are conduction and radiation, not convection. A 4 meter drop test will simulate the
impulse the payload will experience during landing.
7.0 Launch Requirements
Clock synchronization with GPS system will be required in order to have a concrete base of time
to plot readings against. Power switch will also need to be activated prior to launch.
7.1 Flight Requirements and Operations
The flight is expected to be approximately 2 to 2 ½ hours, with a relatively constant ascension
rate to an altitude of 30km. We will need to know altitude as a function of time from launch
until landing.
7.2 Data Acquisition and Analysis Plan
Operation Ozone will be acquiring UV radiation data as a function of altitude. All data will be
collected and stored in the payload’s EEPROM, no data will be collected through telemetry.
GPS data will be collected post flight from the LA ACES panel. Once data is collected group
members using software such as Excel will analyze it.
Data to be collected in flight:
External Temperature
UV Flux
Atmospheric pressure
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8.0 Project Management
To ensure the schedule is met on time all members have been given specific assignments and
timelines to accomplish their tasks within. Periodic checks and weekly meetings help ensure that
all tasks are being accomplished in a timely manner. These meetings also bring potential
problems to the attention of the entire group so that the issue can be resolved as quickly as
possible.
8.1 Interface Control
Operation Ozone has a primary system consisting of the BalloonSAT that controls the UV sensor
and the data logging of its output, as well as internal temperature monitoring and thermal
regulation control. Its secondary systems are the HOBO data logger, the thermal system, and the
power system.
The HOBO data logger will be independent of the BalloonSAT and is responsible for logging the
output from the external temperature thermocouple and the pressure transducer.
The power system will be physically attached to the thermal system to ensure optimal
temperature maintenance throughout flight. It will be routed to the BalloonSAT in order to
provide power throughout flight.
The thermal system will be powered independently of the rest of the payload’s systems;
however, its activation will be controlled by the BalloonSAT and set to be activated when
internal temperatures drop to 273K or less. This will conserve the power source of the thermal
system until it is needed. The thermal system will be placed in direct contact with as many of the
payload components as possible; those components that can not be placed in physical contact
will be placed as close as possible and attached with a heat conductive metal to maximize heat
transfer by radiation as well as conduction.
The payload itself will not interface with any other payload or the spacecraft. Guiding cables
through the payload and securing them will accomplish physical attachment.
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9.0 Master Schedule
Milestone
1
2
3
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
C Task
Proceeding Task
Responsibility
√ Order Photodiodes
0
Gregg Ridlon
√ Research UV flux/atmospheric science 0
Donald Swart
PDR
2
Team UNO
√ Construct test box
0
Robert, Gregg, Donald
√ Construct thermal system
0
Donald Swart
Write thermal control software
5
Michael O’Leary
Test thermal control
4, 6
Donald Swart
√ Design UV summing circuit
0
Gregg Ridlon
Acquire op amps
0
Michael O’Leary
Construct summing circuits
8, 9
Donald Swart
Construct radiation test array
10
Gregg Ridlon
Software development
11
Michael O’Leary
Test radiation test array
12
O’Leary, Ridlon
Impact testing
4, 11
Schefferstein, Ridlon
Thermal testing
7, 11
Schefferstein, Swart
CDR
13, 14, 15
Team UNO
Construct mechanical system
16
Robert Schefferstein
Construct radiation detection array
16
Ridlon, O’Leary
Calibrate radiation detection array
18
Christopher Barber
Construct thermal control system
16
Donald Swart
Integrate all system components
17, 19, 20
Ridlon, Swart, O’Leary
Write algorithms for data recovery
21
Michael O’Leary
Finalize presentation
16
Swart, Barber
FRR
22, 23
Team UNO
Table 5 – Work Breakdown Structure
9.1 Staffing Plan
Donald Swart
Christopher Barber
Gregg Ridlon
Robert Schefferstein
Michael O’Leary
Team UNO
Team Leader/Data Analysis
Research/Data Analysis
Electronics/Construction
Construction
Programming/Construction
14
PDR v2.0
9.2 Projected Timeline
Task
Payload Design
Order Parts
PDR
Test Box Fabrication
Thermal Design
UV summing circuit design
Fabricate summing circuit
Write thermal control software
Test thermal control
Radiation test array fabrication
Complete software
Test radiation array
Impact testing
CDR Document
CDR
Fabrication of payload shell
Fabrication of UV array
UV array calibration
Final thermal control fabrication
Integrate systems and final testing
Data processing algorithms
Presentation finalize
Payload is launch ready
FRR and Flight
Date Started
21 Mar 2005
31 Mar 2005
31 Mar 2005
5 Apr 2005
5 Apr 2005
5 Apr 2005
7 Apr 2005
7 Apr 2005
13 Apr 2005
12 Apr 2005
14 Apr 2005
19 Apr 2005
25 Apr 2005
19 Apr 2005
28 Apr 2005
1 May 2005
1 May 2005
3 May 2005
3 May 2005
11 May 2005
13 May 2005
18 May 2005
20 May 2005
22 May 2005
Deadline
28 Mar 2005
5 Apr 2005
9 Apr 2005
9 Apr 2005
9 Apr 2005
9 Apr 2005
12 Apr 2005
12 Apr 2005
14 Apr 2005
14 Apr 2005
17 Apr 2005
21 Apr 2005
26 Apr 2005
26 Apr 2005
1 Mar 2005
3 May 2005
3 May 2005
10 May 2005
4 May 2005
16 May 2005
18 May 2005
19 May 2005
22 May 2005
26 May 2005
Completed
25 Mar 2005
5 Apr 2005
5 Apr 2005
5 Apr 2005
5 Apr 2005
Table 6 – Project Timeline
Team UNO
15
PDR v2.0
10.0 Master Budget
Ozone measurement Bill of Materials
Name
Vendor
Source
Delivery
Time
Qty
Part No.
Price per
quantity
Price
UVBC Photodiodes
Electro Optical
Components
www.eoc-inc.com
3 weeks
4
JEC 0.3 BC2
$110.00
$ 440.00
EEPROM Memory Chip 256 K
Digi Key
$ 2.75
$ 2.75
1
Relay switch
1
Op Amp
Digi Key
5
AD8067ART-R2CT-ND $ 6.46
5660 pF capacitors
Digi Key
10
P4170-ND
$ .33
$ 32.30
$ 3.30
100k ohm resistor
UNO store room
In stock
5
2.8k ohm resistor
Digi Key
In Stock
5
2.80KXBK-ND
$ .11
$ .55
4 ohm resistors
UNO store room
In Stock
3
N/A
N/A
N/A
1
480-1915-ND
$ 30.11
$ 30.11
.5 m2
N/A
N/A
N/A
1
Thermocouple
Pressure Transducer
Digi Key
Foam Board
UNO store room
Polystyrene
Lowe’s Hardware
In Stock
2.25 m
$ 3.11
$ 7.00T
Aluminum Tape
Lowe’s Hardware
In Stock
46m
$ .31
$ 14.00T
9V Industrial Batteries
Energizer
In Stock
10
In Stock
Batteries Plus
2
$7.50
$ 75.00T
Contingency (Materials not Included)
1
L522
$ 50.00
$ 50.00
Shipping Costs
1
$ 50.00
$ 50.00
Taxes (where app.)
Total
9.00 %
$ 453.56
Table 7 – Project budget
10.1 Material Acquisition Plan
Some components will be ordered from online sources. All purchases will be reviewed
thoroughly by the team leader and other group members, and as many sources will be found as
practical for all high dollar items.
The long-lead items of immediate concern are the photodiodes. All other items can be obtained
locally or quickly through the postal services.
11.0 Risk Management and Contingency
Major risks to the payload include severe temperature changes, low power at extreme
temperatures, impact damage to sensitive components, bursting pressure at extreme altitudes if
not vented. Administrative concerns of note are the successful completion of all assigned tasks
by projected completion date or, at latest, the deadline date.
Mitigating factors include a heating system that works in conjunction with a sturdy mechanical
system to keep all components at operational temperatures. All sensitive components will have
extra padding to ensure safe landing at impact.
Team UNO
16
PDR v2.0
A 30 to 45 minute administrative meeting will be held at the conclusion of every day’s work to
go over all system progress and identify problems to the group. The group leader will make sure
that all available manpower is used to its fullest ability and will reassign personnel or postpone
projects until such times that problems can be successfully handled and overcome within
reasonable deviation to planned schedule.
Team UNO
17
PDR v2.0
Risk Matrix
Event
Prob.
Effect
Sub-risk
Control
Final Risk
Temp Damage
4
3
12 H
Heater
6M
Low Power at alt.
3
4
12 H
High Cap Batt/heat
6M
Impact Damage
5
3
15 E
Insulation/Padding
5M
Work Lag
3
3
9H
Meetings/Delegation
6M
Low Pressure
burst
2
4
8M
Venting
4L
Total Risk
5M
Probability
Effect
5 - Def
4 - Likely
3 - Occ.
2 - Remote
1 - Unlikely
20
16
12
8
4
1 – 4 Low
3 - Critical
15
12
9
6
3
5 - 8 Moderate
2 - Marginal
10
8
6
4
2
9 – 14 High
5
4
3
2
1
15+ Extreme
4 - Catastrophic
1 - Negligible
Control Measures reduce either the probability or the effect, but usually not both
Definite - Will happen continuously over course of
flight
Catastrophic - Total loss of payload, total loss of data
Likely - Will happen for short durations frequently or
once for a prolonged period
Critical - Major damage that could compromise a large
portion of our data
Occasional - Will happen for short durations
Marginal - Minor damage that could result in a loss of a
small portion of data
Remote - Will happen once or twice times for short
durations
Negligible - Mostly superficial, won't harm data collection
or retrieval
Unlikely - Will happen once during entire flight for a
short time
Table 8 – Risk Matrix
Team UNO
18
PDR v2.0
12.0 Glossary
La ACES
ADC
CDR
DCU
EOF
EEPROM
FRR
GPS
PDR
STP
TBD
TBS
UV
WBS
Team UNO
Louisiana Aerospace Catalyst Experiences for Students
Analog to Digital Converter
Critical Design Review
Data Collection Unit
End of File
Electronically Erasable Programmable Read Only Memory
Flight Readiness Review
Global Positioning Satellite
Preliminary Design Review
Standard Temperature and Pressure (P = 1 atm (approx 1013mb) and T = 273K)
To be determined
To be supplied
Ultra Violet
Work breakdown structure
19
PDR v2.0