High Altitude Balloon Payload Design Project Mission Objective "To collect data from a custom radiation sensor in a high altitude environment." -Detects location of ionizing radiation strikes -Tested with variety of radiation sources -Ready for testing in representative environment Design Team: Laurie Smoot (EE) Tiffany Heetderks (EE) Stephani Schielke (CS) Rachael Luhr (CS) Lizi Clem (MET) Katie Schipf (ME) Advisors: Dr. Brock J. LaMeres - Electrical & Computer Engineering Dr. Angela Des Jardins - Montana Space Grant Consortium Hunter Lloyd - Computer Science Robb Larson - Mechanical & Industrial Engineering Sponsor : NASA Budget: $450 Schedule: 8 Weeks 6/6/11 - 7/29/11 Level 1 Requirements Functional Requirements: Log and store data from a custom radiation sensor while the sensor is flown on a high altitude balloon. Power the sensor and computer system Protect the system from environmental elements during flight Protect the system from impact upon landing Self-monitor power system Level 1 Requirements Continued Performance Requirements: Log data from sensor to provide sufficient information about the radiation environment Provide power for the duration of mission Store data on non-volatile memory that can be retrieved regardless of power failure Preserve data in the worst-case landing scenario (100k feet free fall, water, fire, animal) Be able to log power failures for sufficient analysis Level 1 Requirements Continued Physical Requirements: Must not exceed 2.72 kg Must fit in a 15 cm x 15 cm x 30 cm box. Must mechanically and electrically interface to BOREALIS system with HASP considerations Must be able to withstand temperatures from -60C to +40C (-60C to 60C for HASP) Level 1 Requirements Continued Reliability Requirements: Must be able to be launched one time System Architecture Computer Subsystem Electrical Subsystem Mechanical Subsystem -Log Data Log once every microsecond Log for a duration of 4 hours -Specifications Number of channels >32 digital 1 analog Computer Design Criteria Concept Generation Idea #1 Arduino Mega 2560 54 digital GPIOs 16 MHz clock speed Operating Voltage: 5V x x 15.29mm SRAM: 8KB; Flash: 256KB Weight: 34.9g Total Cost: $69.00 Computer System Concept Generation Idea #2 Emartee Nano Mega 2560 70 digital GPIOs 16 MHz clock speed Operating Voltage: 5V 71 x 53 x 11.3mm SRAM: 8KB; Flash: 256KB Total Cost: $55.00 Computer System Concept Generation Idea #3 LeafLabs Maple 39 digital GPIOs 72 MHz clock speed Operating Voltage: 3.3V x x 14mm SRAM: 20KB; Flash: 64KB Weight: 17g Total Cost: $59.00 Computer System Preliminary Analysis Number of digital I/O pins > 32 for radiation sensor interface Non-volatile Storage o SD Card Write Speed: 17.8 MB/s o USB Flash Drive Write Speed: 5.5 MB/s Data Logger Shield o Independent power supply to monitor electrical subsystem with time stamps Voltage 3.3V o More compatible with power system, radiation sensor and Data Logger 72MHz clock speed allows more Write instructions per cycle Computer System Design Selection: Decision Matrix Final Selection: LeafLabs Maple Adafruit Data Logging Shield Industrial-Grade Wide Temperature SD Card Computer System Importance Scale: 1-5 Rating Scale: 1-10 (One being the lowest Score) -Provide Power Computer System (~0.5 W) Sensor (~2 W) -Specifications Voltage (+/- 3.3V and/or +5V) Lifetime (4 hours) Temperature (-40 to +40 C) Electrical Design Criteria Concept Generation Idea #1- DC/DC Converter SUS10123R3/SUS Input Voltage Range: 9-18V Output Voltage: 3.3V or 5V Maximum Output Current: 2.6A or 2 A Efficiency: 82% or 85% Temperature Range: -40 C to 85 C Price: $29 Electrical System Concept Generation Idea #2 DC/DC Converter 1003S12HN/1005S12HN Input Voltage Range: 9-18 V Output Voltage: 3.3 V or 5 V Maximum Output Current: 2.4 A or 2 A Weight: 16g Efficiency: 78% or 82% Temperature Range:- 40 C to +105 C Price: $27 Electrical System Concept Generation Idea #3 DC/DC Converter MJWI10-24S033/MJWI10-24S05 Input Voltage Range: 9-36 V Output Voltage: 3.3 V or 5 V Maximum Output Current: 2.2 A or 2 A Weight: 15g Efficiency: 86% or 84% Temperature Range: -40 C to +60 C Price: $21 Electrical System Concept Generation Electrical System Idea #4 DC/DC Converter CC6-0503SF-E Input Voltage Range: 4.5V 9V Output Voltage: 3.3V Maximum Output Current: 1.2A Weight: 15g Efficiency: 76% Temperature Range: -40 C to +85 C Price: $16 Idea #1 --- Battery Selection Energizer Ultimate Lithium Output Voltage 1.5V Max Output Current 2 A Temperature Range -40C to 60C Weight 14.5 g Cost ~$3/battery Concept Generation Electrical System Idea #2 --- Battery Selection Energizer Advanced Lithium Output Voltage 1.5V Max Output Current 1.5A Temperature Range -40C to 60C Weight 14.5 g Cost ~$2/battery Concept Generation Electrical System Idea #3 --- Battery Selection UltraFire Li-Ion Rechargeable Ouput Voltage 3.6V Max Ouput Current 0.9A Temperature Range -40C to 60C Weight 44.5 g Cost ~$7/battery and ~ $17/charger Concept Generation Electrical System Preliminary Analysis Power = IV [W] Power = (I in )(V in ) = (I out )(V out )/(Efficiency) Output Voltage: -3.3V/+3.3V Output Current: Sensor: +3.3V A -3.3V A Computer: 0.15A Input Voltage: -12V/+12V Electrical System Design Selection: Decision Matrix Electrical System Design Selection: Decision Matrix Electrical System Importance Scale: 1-5 Rating Scale: 1-10 (One being the lowest Score) Final Selection: Energizer Advanced Lithium Design Selection: Decision Matrix Final Selection: CC6-0503SF-E DC\DC Converter Electrical System Importance Scale: 1-5 Rating Scale: 1-10 (One being the lowest Score) Mechanical Design Criteria -Protection Temperature (-60C to +60C) Wind Impact (protect SD card) -Fit to HASP constraints -Packaging (everything fits in the box) -Specifications Weight (2.72 kg) Dimensions (15x15x30 cm) Concept Generation Materials evaluated to meet thermal requirements: Polystyrene - Extended Polystyrene - Extruded Polyisocyanurate (Foam board used by BOREALIS) Thermasheath 3 Insulation Materials evaluated for added durability: Plexiglass shell Fiberglass cloth with resin Mechanical System MSU! Concept Generation Cont. Mechanical System Material Properties Table: Thickness, Thermal Resistance, Mass, and Cost Preliminary Analysis: Thermal 2D Heat Transfer Analysis Concepts: Conductive Heat Transfer: Q (W) = kA T/X k = thermal conductivity (W/mK) A = cross sectional area (m 2 ) dT = change in temperature (K) X = thickness of the material (m) Thermal Resistance (R) = X/k therefore; Q = T/R Mechanical System Preliminary Analysis Cont: Thermal 3D heat transfer analysis: For a rough estimate, a shape factor (S) is used to estimate the heat transfer through all sides of the payload. Resulting in the equation: For internal temperature (Ti): Mechanical System Shape factor for square channel of length L* *Table 4.1in Intro to Heat Transfer by Incropera Preliminary Analysis Cont: Thermal Analysis to determine insulating material for payload Computer and Electrical operating range: -40 C to 85 C (Inside temperature) Atmosphere temperature conditions: -60 C to 40 C (Outside temperature) Mechanical System Alternative Evaluation Alternative #1: To meet temperature AND durability Polyisocyanurate Rigid Foam Insulated Sheathing Standard insulating foam used for BOREALIS flights R-value of K*m2/W o Capable of maintaining internal operation temp Cost: $11.00 Weight: 0.23 kg Mechanical System Alternative Evaluation Cont. Alternative #2: To meet temperature AND durability Polyisocyanurate Foam with Plexiglass casing Increased durability R-value of 1.15 K*m2/W o Capable of maintaining internal operation temp Cost: $20.00 Weight: 0.761kg Mechanical System Alternative Evaluation Cont. Alternative #3: To meet temperature AND durability Polyisocyanurate Rigid Foam Insulated Sheathing with Fiberglass Fabric and Resin Increased durability protects foam from damage and able to reuse payload. Waterproof R-value of K*m2/W o Capable of maintaining internal operation temp Cost: $33.00 Weight: kg Mechanical System Design Selection Final Section: Polyisocyanurate Rigid Foam Insulated Sheathing Fiberglass Fabric and Resin Mechanical System Importance Scale: 1-5 Rating Scale: 1-10 (One being the lowest Score) Selection of the Best Idea LeafLabs Maple Adafruit Data Logging Shield Industrial-Grade Wide-Temperature SD Card CC6-0503SF-E DC/DC Converter Energizer Advanced Lithium Batteries Polyisocyanurate Rigid Foam Fiberglass fabric and Resin MechanicalElectricalComputer Final Design Selection Total Mass of the Payload Sensor = 83.5 grams Computer System: Data Logging Shield = 22 grams LeafLabs Maple = 17 grams Electrical System: Battery Box (2) = 72 grams Batteries (16) = 232 grams DC-DC Converter (2) = 32 grams Protoboard (1) = 37.2 grams Mechanical System: Payload = grams Inner materials = 150 grams Assembly materials = 200 grams TOTAL: grams kg Click to edit the outline text format Second Outline Level Third Outline Level Fourth Outline Level Fifth Outline Level Sixth Outline Level Seventh Outline Level Eighth Outline Level Ninth Outline LevelClick to edit Master text styles Second level Third level Fourth level Fifth level Budget ($450) Computer System: Data Logger Shield: $24 LeafLabs Maple:$60 Rugged SD Card: $53 Total: $137 Electrical System: DC/DC Converter: $40 Lithium Batteries: $70 Battery Box: $6 Protoboard: $3 Wires: $7 Total: $126 Mechanical System: Box Material: $33 Extra Inner Insulation: $15 Assembly Materials: $20 Total: $68 Grand Total $ $331 Approximately $119 Under Budget (for preliminary design considerations) Schedule HASP vs. BOREALIS HASPBOREALIS Altitude126,000 ft100,000 ft Flight Time15-20 hours (stays at altitude) 100 min. Power SupplySupplied by HASP-payload plugs into their main supply Self-Powered Temperature Range-60 to +60C *Absorbs more heat from sun while sitting at altitude -60 to +40C HASP Design Considerations: Electrical System: Would need to consider and design for a 30V input. Design a circuit that would produce a positive and a negative input voltage. Choose a DC to DC switched-mode converter that would operate for new input voltage. Mechanical System: Overheating in the sun may cause damage to the electronics since the balloon will be at altitude for an extended period of time. o Add heat sink to actively cool electronic system o Change color and reflectivity of the payload to decrease the absorbance and change emissivity in order to deflect some of the sun's rays. Questions? Thank you!