High Altitude Balloon Payload Design Project Critical Design Review July 17, 2012

Design Team: Jen Hoff (EE) Kate Ferris (EE) Alison Figueira (CS) Makenzie Guyer (CS) Kaysha Young (ME/MET) Emily Bishop (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

To collect measurements at high altitudes of atmospheric temperature and pressure, the internal temperature and dynamic movement of a payload that meets HASP flight requirements. Mission Objective Budget: $500 Schedule: 8 Weeks 6/4/12 -7/27/12

Functional Requirements Log/Store data from the sensors on a non-viotile storage device Power Sensors and any electronics needed to run these sensors Protect the system from environmental conditions Protected from the impact upon landing/jerk from the balloon pop Provide state of health information of the system Performance Requirements Consume 5 watts in order to accurately represent the research team’s thermal output Log data from the temperature and pressure sensors at a rate of 1 measurement per second Provide insulation to keep the internal temperature between -40 C and 60C Must provide at least 4 hours of power for the duration of the setup, flight, and recovery time. Must withstand an vertical force of 10 G and a horizontal force of 5 G Physical Requirements Must weight 1.62 kg Maximum Total Volume: 15 cm x 15 cm x 30 cm Must mechanically interface with the HASP payload plate in addition to the BOREALIS system Reliability Requirements Must be able to survive preliminary tests and two launches Mission Requirements

2012 Payload Computer System Electrical SystemMechanical System System Architecture

Computer System Logging DataInterpreting Data Reading from Sensors SD CardSD Shield 2012 Payload Computer System Electrical System Mechanical System

Goes through same process for Pressure Sensor, and all Three Temperature Sensors Start Setup: Start LED’s, define pins, startup SD library, startup IMU, define timers Loop: Update Timers, average IMU data Timer goes off Retrieve Data Interpret Data Store in RAM Store on SD card, with timestamp (millis) Analog Sensors Event Get Accelerometer and Gyroscope Values Average Values Store current averages in Array IMU Event Store IMU averages to SD card with timestamp (millis) Reset current averages and clear average array Program Flow Chart

Testing SD card Timer Events SD card, RTC (not used), and timers Reading from Analog Sensors Reading from IMU

Testing Cont. Timer Events

Testing Cont. SD card, RTC, and timers

Testing Cont. Reading From Analog Sensors

Data from Burn In Test RTC was not working correctly, addressing problem with Gyroscope, but it was able to record and store data for the duration of the Burn In Test

Cold Test In the second cold test, only the analog sensor data was collected. Problem with temperature sensors Collected data every second for duration milliseconds ~ minutes

Refrigerator Test After getting new temperature sensors, the computer and sensor were placed in the fridge for ~10 min. trials. The fridge got down to 8C.

Flight Plan For the first flight, just the analog sensors (pressure and three temperature) will be used. Between flights the IMU will be tested (addressing issue is fixed) Second flight will have all sensors hooked up.

Budget

Electrical System Sensors Power System Batteries Pressure Temperature Movement Acceleration Interfacing Electrical System 2012 Payload Computer System Electrical System Mechanical System

Schematic

Burn In Test

Burn In Test Results BURN-IN TEST TIME VOLTAGE of BatteriesCURRENT from BatteriesVOLTAGE 3.3CURRENT from minutes 14.2 V0.07 A3.29 V7.8 mA 5 minutes 12.4 V0.068 A3.298 V7.6 mA 10 minutes V A3.299 V7.8 mA 15 minutes V0.068 A3.299 V7.7 mA 20 minutes V A V7.7 mA 25 minutes V0.068 A V7.6 mA 30 minutes V0.071 A V6.8 mA 35 minutes V0.071 A V6.8 mA 40 minutes V0.071 A V6.8 mA 45 minutes V0.071 A V6.8 mA 50 minutes V0.071 A V6.8 mA 60 minutes V0.071 A V6.8 mA 70 minutes V0.071 A V6.8 mA 80 minutes V0.071 A V6.8 mA 90 minutes V0.071 A V6.8 mA 100 minutes V0.071 A V6.8 mA 130 minutes V0.071 A V6.8 mA 160 minutes V0.071 A3.299 V6.8 mA 190 minutes V0.071 A3.299 V6.8 mA 220 minutes V0.071 A3.299 V6.8 mA

Burn In Test  Total Discharge  Needed to add power resistors which updated the current pulled from the batteries to A

Cold Test  Cold Test  Put the temp sensor into the fridge with an external temp sensor and recorded the values of the test.

Output Wattage  Power Resistors  Needed to add 2W to the inside of the payload to reach the required 5W

Output Wattage Pressure: Temp Sensors: Batteries: Power Resistor: Total: P=I*V

Mass Budget  Mass of the inside of the Payload  Weighted 0.73lbs.

Budget Sensors(+shipping): $ Batteries: $82.32 Battery Boxes: $4.58 PC Board: $12.81 Headers: $12.76 Total: $237.86

Mechanical System Structural System Thermal Structure Temperature Material Enclosure Attachment Impact Mechanical System 2012 Payload Computer System Electrical System Mechanical System

Thermal i. Must be similar to the MSU HASP Research Team structure materials 1.Polystyrene must be used for the insulation (approx. 1 cm thickness) 2.A shiny reflective aluminum coating should be applied 3.Additional material or support structures will be needed to make the structure strong ii. The internal temperature of the payload must be kept between -40 C and 60 C Structural System i. Enclosure 1. The external volume may not exceed in x in x 11.8 in (15 cm x 15 cm x 30 cm) 2. The internal volume must be at least in 3 : 4.5 in x 4.5 in x 6.5 in ii. Attach Enclosure Structure 1. HASP 1. Enclosure must securely attach to HASP Plate and not be disconnected for the duration of the flight 2. Must be easily attached and unattached from the ASP plate for ease of assembly and disassembly 2. BOREALIS 1.Must attach to the BOREALIS rope connection system iii. Impact Forces 1. Must withstand a vertical impulse force of 10 G’s 2. Must withstand a horizontal impulse force of 5 G’s Mechanical Systems Requirements

Preliminary Design Review Results

Immediate Changes to the PDR ** Reduced height to 6 inches ** Choose to not use corner rebar wire ** Changed L Brackets to Corner Brackets ** Not using Plaskolite

Assembly : Initial Trials Fiberglass and Resin + foam = disaster Fiberglass and Resin + Aluminum foil + duck tape = success

New Design Implementations Improved Design Considerations Access Electronics while they are attached to HASP Plate No Reflective surfaces as not to interfere with other HASP Payloads HASP Power Cord entrance Implementing Technique Make the top and one side panel removable Paint the exterior white Cut a small aperture at the back of the payload for cords to run in.

Payload : Structural Elements Structural Support Enhancers: * Fiber Glass Cloth * Corner Brackets 0.5” thick Expanded Polystyrene Insulation White Reflective Paint Fiber Glass Cloth W/ resin Material Configuration

Payload :Electronic Stabilization * 4-40 Hex Socket Cap Screws

Payload : Exterior Surface Krylon Flat White Paint - Chosen by the HASP team due to research done by prior space flight teams from MSU

Payload : Assembly -HASP Plate -High Conductive Copper Heat Sink -3 walled structure -1 wall - 1 top -17 – x ½” button head screws - 4 – x 1” button head screws -4 – 4-40 x 1.25” hex socket cap screws x 2.0” hex socket cap screws

Payload : Attachment to HASP Corner Brackets 4 – x 1” button head screws 4 - #10 Nuts

Payload : Attachment to BOREALIS Due to odd shape and unevenly distributed weight, the BOREALIS Team is configuring an attachment plan.

Type of Test -Drop Test -Long Term Thermal Test What will be Tested - Accelerometers -Structure components -Insulation -Heat Sink Mechanical System - Testing

Test #1 : Drop Tests Accelerometer Testing ** Must withstand a 10 G vertical load ** Must withstand a 5 G horizontal load Test: The accelerometer was attached to the inside of the box with duct tape. A lab view program was set up to collect acceleration data from X, Y, Z, and Total Acceleration. The interior was padded with packing foam. The box was dropped from various heights, ensuring that the G loads were met.

Test #1 : Drop Test Results Vertical Test Horizontal Test Maximum Load: 15 G Maximum Load : X - 8 G Y – 10 G

Test #1 : Drop Test Results A drop test was completed to test the ability of the box to withstand a much higher load. The over all acceleration reached over 20 G, and the vertical load reached 19 G. The enclosure showed no signs of wear or tear after these tests The enclosure will withstand the G loads required by HASP

Test #2: Thermal Test Cold Room Test: *Cold room at -60 C *Raise temperature to - 20C *No results due to failure to collect data from temperature sensors due to electronic problems

Mechanical Systems Mass Budget QuantityWeight/Piece (g)Total Weight Extruded Polystyrene1150 Fiber Glass and Resin122.5 Brackets Bracket Mounting Hardware HASP Mounting Material CCA Stack Mounting Standoff Total Mass

MaterialCost Extruded Polystyrene$12.25 Brackets & Assembly Hardware8.58 Mounting Hardware5.48 Heat Sink34.95 Miscellaneous Assembly Materials (fiberglass, resin, acetone, duct tape, gorilla glue, etc) Paint11.95 Total Mechanical System Budget

Total Budget Computer Science: $62.70 Electrical: $ Mechanical: $ Total: $ Under budget:$57.40

Final Configuration