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Team 7, Final Presentation December 1, 2011
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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
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Design Overview Petri dish attached to servo controlled by Arduino 3 other petri dishes HOBO, heater, camera Function Block Diagram Arduino Uno Parallax Standard Servo
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Design Changes Funnel and holes added New petri dish seal Size reducedSpring added inside
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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
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Dishes Before Incubation
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Dishes After 1 Day of Incubation
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Dishes After 5 Days of Incubation
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Control Dishes Negative Control Positive Control
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Bacteria Capture Dish Before Incubation Day 5 Day 1 No Growth
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Analysis of Bacteria No bacteria collected from the tropopause o Broken seal o No bacteria growth due to dryness of agar Bacterial growth on all three flight dishes o Colonies for all three look different Possibly not growing just E. Coli
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Analysis of Bacteria Dish 3 looked similar to the control Dishes 1 and 2 had different color and shape o Sterile incubation techniques were used o Plates may still have been contaminated by bacteria in the air The negative control had no growth o Possibly because it was not exposed to the air long enough to be contaminated o Or because it was only incubated for 1 day
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Predictions vs. Results Prediction: only the dish exposed to nothing would grow bacteria o All three dishes ended up growing bacteria Prediction: mission would successfully capture and grow bacteria from the tropopause o No bacteria grew in that dish
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Sunrise Launch In tropopause during ascent Burst Times when petri dish was open In tropopause during descent Landing Black Line: External Temperature Blue Line: Altitude External Temperature and Altitude
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Black Line: Internal Temperature Blue Line: Altitude Sunrise 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
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Black Line: Relative Humidity 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
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Pictures
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Flight Recap Bacteria grew on all three flight dishes Broken seal and no growth for collection dish Insulation failure o Low internal temperature o Camera shut down
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Failure Analysis Camera Failure o 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
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Failure Analysis Continued Resealing Petri Dish Failure o Petri dish landed unsealed Hard landing Dish not supported by Foam Core underneath
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Thermal Failure Insulation failure led to internal temperature of -50 degrees o Needed foam, not thermal blanket Results repeated in cold test o Showed problem was with insulation, not heater as in initial tests Test begins Test ends
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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.
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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
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Ready to Fly Again Payload preparation o Sterilize petri dishes o Fill dishes with agar o Put bacteria in three dishes Payload activation o Press button to activate camera o Flip switches to activate servo and heater o Insert pin connecting servo arm to petri dish after arm has twitched to confirm activation
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RFP Requirement Compliance RequirementRequirement Met Mission: 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
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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
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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.
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