Transcript PCC

Pre-Flight Briefing
ANSR-79
Pima Community College
3/28/14
Team Members
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Nick Patzke
Gustavo Guerreo
Nick Morris
Why can’t we successfully fly a
GoPro camera through space in
a “naked” state?
Payload Motivation
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Payloads used in ANSR balloon flights are subjected to temperatures as
low -60 C which usually require additional heating and insulation.
This results in limited mounting configurations, additional weight and
take up space better served for circuit boards, etc.
Most ANSR payloads have some form of camera (still or video), that
generally require special attention.
Most payload camera failures are the result of battery “failure” at
extreme temperatures.
GoPro technical staff have no data on their cameras and their behavior
at low temperatures.
The goal for this flight is to examine GoPro camera behavior during an
ANSR flight.
Payload Objectives
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5V Regulator
Build a simple payload holding two GoPro
cameras aimed at answering questions
about their usability in extreme conditions.
Lamp-rod Configuration:
One GoPro with OEM battery as a control
‘group.’
Another GoPro powered by a larger capacity
and voltage battery.
(LiPo 11.1v 3S 2250 mAh)
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GoPro 2
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GoPro 3
GoPro Issues In Space
The Battery
Li-Ion batteries shipped with GoPro cameras today are specified to have a
minimum operating temperature of -40 C
For most applications, this limit is far lower than the camera or battery will ever
experience.
But we want to send them into near space and back…(min expected temp
~-60C)
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But Why Can’t a Battery Operate at < -40C ?
A batteries’ internal resistance increases as temperature decreases:
As internal resistance increases, load voltage decreases:
As load voltage decreases, available current decreases:
At some point (due to the cold) the available current should decrease past
the necessary 0.5A needed and the camera will shut off. 
Or the remote possibility of a defective battery…
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Payload Structure
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Both GoPros (in their protective
cases) will be exposed equally to the
elements:
One with stock battery. (Li-Ion)
Facing balloon.
One with a larger Li-Po battery
Facing toward Earth.
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Battery Testing
Test Box
Lab
Temperature vs Load Voltage and Internal Resistance
4.1
7
Big battery voltage
3.9
5
3.5
4
3.3
3
3.1
2
2.9
Internal Resistance (Ohms)
6
3.7
Load Voltage (V)
GoPro2
Load V
GoPro3
Load V
Big
Battery
IR
GoPro2
1
2.7
2.5
0
-45
-35
-25
-15
-5
Temperature (C)
5
15
25
IR
GoPro3
Acknowledgements
Special thanks to the following for offering this opportunity!:
Jack Crabtree and ANSR
Susan Brew and NASA Space Grant
Mike Sampogna
Dr. Denise Meeks