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.