High Altitude Balloon Payload Design ProjectCritical 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 EngineeringDr. Angela Des Jardins -Montana Space Grant ConsortiumHunter Lloyd -Computer ScienceRobb 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: $500Schedule: 8 Weeks6/4/12 -7/27/12
Functional RequirementsLog/Store data from the sensors on a non-viotile storage devicePower Sensors and any electronics needed to run these sensorsProtect the system from environmental conditionsProtected from the impact upon landing/jerk from the balloon popProvide state of health information of the system
Performance RequirementsConsume 5 watts in order to accurately represent the research team’s thermal outputLog data from the temperature and pressure sensors at a rate of 1 measurement per secondProvide insulation to keep the internal temperature between -40 C and 60CMust 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 RequirementsMust weight 1.62 kgMaximum Total Volume: 15 cm x 15 cm x 30 cmMust mechanically interface with the HASP payload plate in addition to the BOREALIS system
Reliability RequirementsMust be able to survive preliminary tests and two launches
Mission Requirements
2012 Payload
Computer System Electrical System Mechanical System
System Architecture
Computer System
Computer System
Logging Data Interpreting Data Reading from Sensors
SD Card SD 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.
• 5753462 milliseconds ~ 95.891 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
BudgetUnit Price Shipping TotalArduino Uno R3 29.95 13.25 43.2Adafruit Data Logger 19.5 0 19.5
Total 62.7
Electrical System
SensorsPower System
Batteries
PressureTemperature
Movement Acceleration
Interfacing
Electrical System2012
Payload
Computer System
Electrical System
Mechanical System
Schematic
Burn In Test
Burn In Test Results
BURN-IN TESTTIME VOLTAGE of Batteries CURRENT from Batteries VOLTAGE 3.3 CURRENT from 3.3
0 minutes 14.2 V 0.07 A 3.29 V 7.8 mA
5 minutes 12.4 V 0.068 A 3.298 V 7.6 mA
10 minutes 12.13 V 0.0689 A 3.299 V 7.8 mA
15 minutes 12.068 V 0.068 A 3.299 V 7.7 mA
20 minutes 12.057 V 0.0685 A 3.2999 V 7.7 mA
25 minutes 12.056 V 0.068 A 3.2999 V 7.6 mA
30 minutes 12.046 V 0.071 A 3.2999 V 6.8 mA
35 minutes 12.05 V 0.071 A 3.2999 V 6.8 mA
40 minutes 12.056 V 0.071 A 3.2999 V 6.8 mA
45 minutes 12.061 V 0.071 A 3.2999 V 6.8 mA
50 minutes 12.063 V 0.071 A 3.2999 V 6.8 mA
60 minutes 12.069 V 0.071 A 3.2999 V 6.8 mA
70 minutes 12.073 V 0.071 A 3.2999 V 6.8 mA
80 minutes 12.076 V 0.071 A 3.2999 V 6.8 mA
90 minutes 12.079 V 0.071 A 3.2999 V 6.8 mA
100 minutes 12.080 V 0.071 A 3.2998 V 6.8 mA
130 minutes 12.083 V 0.071 A 3.2998 V 6.8 mA
160 minutes 12.087 V 0.071 A 3.299 V 6.8 mA
190 minutes 12.088 V 0.071 A 3.299 V 6.8 mA
220 minutes 12.088 V 0.071 A 3.299 V 6.8 mA
Burn In Test
Total Discharge Needed to add power
resistors which updated the current pulled from the batteries to 0.241919771 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: 0.00528Temp Sensors: 0.0165Batteries: 2.915037Power Resistor: 2.063
Total: 4.999817
P=I*V
Mass Budget
Mass of the inside of the Payload Weighted 0.73lbs.
Budget
Sensors(+shipping): $122.92Batteries: $82.32Battery Boxes: $4.58PC Board: $12.81Headers: $12.76
Total: $237.86
Mechanical System
Structural System
Thermal
StructureTemperature
MaterialEnclosure
Attachment
Impact
Mechanical System
2012 Payload
Computer System
Electrical System
Mechanical System
Thermali. 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 Systemi. Enclosure
1. The external volume may not exceed 5.875 in x 5.875 in x 11.8 in (15 cm x 15 cm x 30 cm)
2. The internal volume must be at least 131.6 in3 : 4.5 in x 4.5 in x 6.5 in
ii. Attach Enclosure Structure1. 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. BOREALIS1. Must attach to the BOREALIS rope connection
systemiii. Impact Forces
1. Must withstand a vertical impulse force of 10 G’s2. 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 – 10-32 x ½” button head screws- 4 – 10-32 x 1” button head screws-4 – 4-40 x 1.25” hex socket cap screws- 4- 4-40 x 2.0” hex socket cap screws
Payload : Attachment to HASP
•Corner Brackets• 4 – 10 32 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
Mechanical Systems Mass Budget Quantity Weight/Piece (g) Total Weight
Extruded Polystyrene 1 150 150
Fiber Glass and Resin 1 22.5 22.5
Brackets 4 28.576 114.304
Bracket Mounting Hardware 4 17.2368 68.9472
HASP Mounting Material 4 9.9804 39.9216
CCA Stack Mounting Standoff 4 10.4338 41.7352
Total Mass 840.51
Material Cost
Extruded Polystyrene $12.25
Brackets & Assembly Hardware 8.58
Mounting Hardware 5.48
Heat Sink 34.95Miscellaneous Assembly Materials
(fiberglass, resin, acetone, duct tape, gorilla glue, etc)
68.81
Paint 11.95
Total 142.02
Mechanical System Budget
Total Budget
Computer Science: $62.70Electrical: $237.86Mechanical: $142.04
Total: $442.60Under budget: $57.40
Final Configuration