Team 7, Final PresentationDecember 1, 2011

Mission Overview

• Send up petri dishes containing bacteria

• Analyze the effects of temperature, pressure, and UV radiation on the bacteria

• Attempt to capture bacteria in tropopause in a sterile petri dish attached to a servo

Design Overview

• Petri dish attached to servo controlled by Arduino• 3 other petri dishes• HOBO, heater, camera

Function Block Diagram

Arduino Uno

ParallaxStandard Servo

Design Changes

Funnel and holes added New petri dish seal

Size reducedSpring added inside

Incubation of Bacteria

• Flight bacteria applied to LB (Luria Bertani) agar plate using sterile swab

• All dishes incubated for 5 days at 37 degrees Celsius

• Dish #1: Flight bacteria exposed to nothing• Dish #2: Bacteria exposed to just UV• Dish #3: Bacteria exposed to UV, low

temperature, and low pressure

Dishes Before Incubation

 

Dishes After 1 Day of Incubation

 

Dishes After 5 Days of Incubation

 

Control Dishes

Negative Control                                             Positive Control

Bacteria Capture Dish

Before Incubation              Day 5                      Day 1

                                     

No Growth

Analysis of Bacteria

• No bacteria collected from the tropopause oBroken sealoNo bacteria growth due to dryness of agar

• Bacterial growth on all three flight dishesoColonies for all three look different

Possibly not growing just E. Coli

Analysis of Bacteria

• Dish 3 looked similar to the control

• Dishes 1 and 2 had different color and shape oSterile incubation techniques were used oPlates may still have been contaminated by

bacteria in the air

• The negative control had no growthoPossibly because it was not exposed to the

air long enough to be contaminatedoOr because it was only incubated for 1 day

Predictions vs. Results

• Prediction: only the dish exposed to nothing would grow bacteriaoAll three dishes ended up growing bacteria

• Prediction: mission would successfully capture and grow bacteria from the tropopauseoNo bacteria grew in that dish

Sunrise

Launch

In tropopause during ascent

Burst

BurstTimes when petri dish was open

In tropopause during descent

Landing

Black Line:ExternalTemperature

Blue Line:Altitude

External Temperature and Altitude

Black Line:InternalTemperature

Blue Line:Altitude

Sunrise

Burst

Burst

Times when petri dish was open

Launch Landing

Near tropopause during descent

Near tropopause during ascent

Interior continues to warm after landing

The satellite’s insulation caused interior temperatures to change after external temperatures; for instance, the coldest interior temperatures were recorded slightly after the satellite went through the tropopause.

Note that the temperature dropped below the -10 degree mark due to failures in heating and insulation.

Internal Temperature and Altitude

Black Line:RelativeHumidity

Blue Line:Altitude

Relative Humidity and Altitude

Launch

Sunrise

In tropopause during ascent

In tropopause during descent

Times when petri dish was open

Burst

Landing

Satellite lying in moist grass in humid Nebraska(61% average humidity*).

Relative humidity roughly increased as temperature decreased. *Source: http://www.wunderground.com/history/airport/KSNY/2011/11/5/DailyHistory.html?req_city=NA&req_state=NA&req_statename=NA

Pictures

Flight Recap

• Bacteria grew on all three flight dishes

• Broken seal and no growth for collection dish

• Insulation failureo Low internal temperatureo Camera shut down

Failure Analysis

• Camera Failureo No pictures taken after

first half of ascent Caused by low

temperature  Confirmed by cold

test• Structural Failures

o Electronics dislodged Faulty attachments Lack of planning

o Air Vent

Failure Analysis Continued

• Resealing Petri Dish Failureo Petri dish landed

unsealed Hard landing Dish not supported

by Foam Core underneath

Thermal Failure• Insulation failure led to internal temperature of -50 degrees

o Needed foam, not thermal blanket

• Results repeated in cold testo Showed problem was with insulation, not heater as in

initial testsTest begins

Test ends

Conclusions

• No bacteria were captured from the tropopause.

• We cannot conclusively state whether or not the bacteria we sent up survived due to some contamination.o The dish that was exposed to UV, vacuum, and low

temperature had colonies that appeared similar to E. Coli so that bacteria apparently survived.

Lessons Learned: Improvements for Next Flight

• Use quartz glass petri dishes for the dishes exposed to UV o Plastic absorbs much of the UV that passes through it

• Use an agar selective to E. Coli to ensure only E. Coli is growing

• Find a way to prevent the agar exposed to the vacuum from drying out

• Secure petri dish more securely to prevent the seal from breaking

• Use foam for insulation in addition to a thermal blanket

Ready to Fly Again

• Payload preparationo Sterilize petri disheso Fill dishes with agaro Put bacteria in three dishes

• Payload activationo Press button to activate camerao Flip switches to activate servo and heatero Insert pin connecting servo arm to petri dish after arm

has twitched to confirm activation

RFP Requirement Compliance

Requirement Requirement MetMission: test if bacteria can survive in near space

Bacterial growth on all three flight dishes

Mission: capture bacteria in the tropopause

Attempted but failed: no bacteria collected

Control the servo for deployment in the tropopause.

Arduino Uno program deployed the servo very near the tropopause

Heat the interior to a temperature of -10 degrees Celsius

Failed: the interior temperature dropped to -50 degrees Celsius

Measure temperature and humidity during flight

HOBO collected data on temperature and humidity

Construct the BalloonSat out of Foam Core

The BalloonSat was made out of Foam Core

Cost and Weight Budgets

Final Budget:     Total Money Spent: $225.68    Budget Remaining: $24.32

Mass:    Total Mass Used: 805 grams    Total Mass Sold: 30 grams    Mass Remaining: 15 grams

Message to Next Semester

• Think of a mission that truly interests your team. If you care about what you might discover, you will find it much easier to stay motivated. Fight through the work; it's worth it. You will miss this class when it is all over.

• Make sure you put a lot of effort into the proposal and the whole project. You will need to do a lot of work to actually do well on it.

• DRESS UP FOR YOUR PRESENTATIONS! It took our class half the semester to figure that one out.