Upload
leo-andrews
View
213
Download
0
Tags:
Embed Size (px)
Citation preview
Pre-Flight Briefing ANSR-79
Pima Community College3/28/14
• Nick Patzke
• Gustavo Guerreo
• Nick Morris
Team Members
Payload Motivation• 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
• 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)
GoPro 2
GoPro 3
5V Regulator
GoPro Issues In SpaceThe 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)
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…