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