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Team Chinese Bandit Ozone Payload Preliminarily Design Report (PDR ). Zach Baum Harry Gao Ryan Moon Sean Walsh. Table of Contents. Document Purpose Mission Goal Objectives Science Background Science Requirements Technical Background Technical Requirements Payload Design
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Team Chinese BanditOzone Payload Preliminarily Design Report (PDR) Zach Baum Harry Gao Ryan Moon Sean Walsh
Table of Contents • Document Purpose • Mission Goal • Objectives • Science Background • Science Requirements • Technical Background • Technical Requirements • Payload Design • Payload Development Plan • Project Management • Glossary
Document Purpose • This document describes the preliminary design for the ozone measurement experiment for Team Chinese Bandits. It fulfills the LaACES project requirements for the Preliminary Design Review (PDR).
Document Scope • This document specifies the scientific purpose and requirement for the Ozone experiment and outlines the general instrument and schedule that we will follow to achieve them.
Change Control and Update Procedures A change cannot be made to these finalized documents unless the following guidelines are met: • Changes can be made to controlled documents pending a consensus. • If a consensus cannot be achieved, the team will address a LaACES staff member for resolution. • A detailed log of changes to this controlled document must be kept. Each change must include the date that the change was made, as well as a reference to what was changed within the controlled document.
MISSION GOAL • Create a profile of ozone concentration with respect to altitude from ground level to 100,000ft. Ozone sensor reading for 2012 UND/UNF HASP payload
Science Objectives • Map peak of ozone concentration in upper atmosphere. • Create ozone concentration profile with respect to altitude. • Map out any fluctuations within ozone profile.
Technical Objectives • The payload must measure ozone concentration • The onboard program will be able to: • Take temperature readings within close proximity to ozone sensor • Maintain proper operating temperature for all necessary components
Science Background Ozone • Converts UV to heat • UV-B,C destroy ozone • UV-C splits O2 UV radiation types A, B and C are absorbed by ozone in different amounts
Science Background Effects of CFC(chlorofluorocarbons) on the ozone Cl + O3 → ClO + O2 ClO + O3 → Cl + 2 O2 Illustration from: The Center for Atmospheric Science, University of Cambridge
Science Background UV and Ozone • Ozone bond energy is 6.04*10^-19 J/bond • O2 bond energy is 8.27*10^-19 J/bond • For O2: λ≤ 240 nm (UVC) • For ozone: 330 nm < λ < 240 nm (UVA,UVB,UVC)
Science Background Oxygen-Ozone Cycle • Creation (λ<240nm) • O2 +hv 2 O • O2 + O + M → O3 + M • Depletion (240nm< λ <270nm) • O3 + hv → O2 + O • O3 + O· → 2 O2 • 2 O· → O2
Science Background • Ozone concentrated in middle and high latitudes • Caused by circulation of stratosphere
Science Requirements • The payload must take measurements of ozone concentration every 3 seconds • Team Chinese Bandits must receive time and altitude GPS information for analysis from LaACES management • The payload must measure the peak ozone concentration to within .2ppmv
Technical Background Ozone Sensor Possibilities • ECC Ozonesonde • Indium Tin Oxide
Technical Background ECC Ozonesonde • O3(g) + 2KI(aq) + H2O --> I2(g) + 2KOH(aq) + O2(g) • Measurement of ozone concentration comes from the rate at which ozone enters the cell and the current produced • Reaction Yields • I2 Violet vapor • 2KOH blue/clear solution • Temperature constraint 0°C to +40°C
Technical Background The Indium-Tin Oxide (ITO) Sensor • Developed by Dr. Patel of North Florida University • Used in recent Avengers LaACES project and HASP programs • Acts like a semiconductor. • (Vacancy) + (O3) → (Oo) + O2 • Must be kept in the operating temperature range of 25-30°C to remain accurate ITO sensors as used by Avengers team in2009-2010
Technical Background Temperature Sensor(Thermistor) • Used to detect temperature of BalloonSat and more specifically, the onboard ozone sensor • Resistor that varies significantly with temperature • Temperature can be approximated by the the following equation Beaded thermistor with insulation
Technical Background Heater • The heater must deliver heat evenly to the ITO sensor to ensure the temperature of all the ITO sensor strips is maintained • Tape heaters such as polyimide (or Kapton) heaters meet this requirement, as well as having: • Low weight • A flat design for easy placement • Low outgassing to function in very low pressures • High watt density transmission
Technical Background GPS Unit • LaACES uses a Lassen iQ GPS unit. The unit can determine accuracy • To the nearest 33 ft with 50% accuracy • To the nearest 52.5 ft with 90% accuracy • UND/UNF used the same GPS
Technical Requirements • The payload must: • Not have a mass greater than 500g • Not exceed 3oz/in2 on any surface • Have two holes 17in apart through which the payload will interface with the balloon • Costs must remain within the allotted $500 budget for Chinese Bandits • In order for the payload to create an ozone profile of the atmosphere, the following requirements must be met: • Payload must take measurements of ozone concentration throughout the flight • Payload must be recovered for post-flight analysis • Altitude must be known to within 65 feet • For the accuracy to be known within 65 feet, the following requirements must be met: • Real-time clock must be synced with GPS time during pre-flight • Real-time clock must be accurate to within 3 seconds of the LaACES LASSEN iQ GPS
Thermal Design • FOAMULAR insulating foam will reduce heat loss • Kapton heaters provide 5 W/in2
Mechanical Design • Regular hexagonal prism • FOAMULAR insulating foam • Lightweight • Thermally insulating
Mechanical Design External Structure
Payload Development PlanElectrical Design Development • Ozone sensor • Select sensor that best meets requirements • Measure ozone to within .2ppmv • Take measurements throughout the flight • Order sensor • Draw sensor schematic • Calibrate sensor • Determine necessary gain for conditioning circuit • Build conditioning circuit • Test in lab conditions with software • Test in simulated flight environment with software • Finalize schematic • Re-evaluate weight budget to make it more accurate • Re-evaluate power budget to make it more accurate
Payload Development PlanSoftware Design Development • Read/Write to EEPROM • Create subroutine to write to EEPROM • Create subroutine to read from EEPROM • Reading sensors • Create subroutine to get data from ADC • Create subroutine to timestamp readings • Temperature control • Create subroutine to read temperature sensor and compare to operating range • Create subroutine to turn on/off heater • Test all programs on circuits in lab environment • Test all programs on circuits in simulated flight environment
Payload Development PlanMechanical Design Development • Determine needed volume to contain components • Determine method of component attachment to payload • Foam cutting and assembling training • Thermal tests to ensure sufficient thickness • Assemble payload • Shock test to confirm system design • Re-evaluate weight budget to make it more accurate
Thermal Design Development • Heater Development • Determine thermal interactions of payload • Determine thermal requirements of heater • Choose heater that best meets thermal requirements • Determine how the heater will be attached to the sensor • Attach heater to sensor • Test heater/sensor configuration, along with software, under simulated flight environment • Re-evaluate power budget to make it more accurate • Re-evaluate weight budget to make it more accurate
Mission Development • The mission will be dependent upon the tasks listed below: • Proper calibration of all sensors is completed • Full flight simulation will be run in order to confirm proper design of all systems • Creation of an hour by hour schedule from 24 hours prior to launch through end of payload operations • Creation of a list of all required spare parts that can be brought within the budget of the payload • Creation of a pre-flight checklist • Create a list of all component calibrations that must be done during pre-flight operations • Creation of a spreadsheet for post-flight data analysis • Creation of a template for the science presentation
Staff Organization and Responsibilities • Zach Baum • Project Manager • Assistant on: • Electrical • Mechanical • Flight Data Analysis • Ryan Moon • Version Control and Editing Lead • Assistant on: • Mechanical • Software • System Testing • Flight Data Analysis
Staff Organization and Responsibilities • Harry Gao • Electrical Lead • Software Lead • Calibrations Lead • Sean Walsh • Mechanical Lead • System Testing Lead • Assistant on: • Calibrations • Version Control and Editing • Writing • Software • Electrical