THE Project

Outline Goals Design Testing Budget Expectations Box Components Program Testing Budget Expectations

Goals Maintain a temperature window for the flight Write a program to measure and record temperature during the flight Write a thermostat program to control the heaters

Mission Operations Program will already be downloaded to the board Plug in batteries Start a stopwatch to keep track of how long after batteries are connected until launch Secure top of box using reflective tape

Design Box Smallest possible to fit the balloon sat board Board fits diagonally – no supports are needed Wires are taped to the side to reduce clutter Tapered edges to create more surface area for a stronger box Reflective tape to reflect visible spectrum of sunlight

Design Components Board components are optimally placed to reduce clutter on the board Heating elements are placed to heat as much area as possible Batteries oppose each other to maintain stability during the flight

Design

Overall EEProm Flight Control Unit Heating Elements Battery Battery Temperature Sensor

Design Program Read and record temperature as a function of time Turn on heater if temperature in box drops below the set low temperature

Program Read and Record Temperature from Sensor Is temperature higher than set low temperature? Is heating element on? Yes No No Yes Turn off heating element Turn on heating element

Testing - Impact Box without mitered joints was constructed A small weight was placed in side to replicate the weight of the balloon sat Dropped off 3rd floor ledge Joints did not fail

Testing - Thermal Filled ice chest with salted ice water Placed box in chest on pedestal such as it was not in contact with the water Ran program for 1 hour Balloon sat recorded temperatures and did not malfunction under low temperature conditions

Testing - Vacuum Box placed in vacuum chamber Chamber was depressurized Box stayed intact Balloon sat still operated at low pressure conditions

Budget Component Price Heating Elements $32 Batteries $8 Wire $6 Temperature Sensor $2 Resistors $5 Accessories $20 Total $73

Budget Weight Total weight is 255 grams 245 GRAMS UNDER WEIGHT LIMIT!!!

Expectations The temperature within the box will not fall below the set low temperature The temperature values will be recorded with a timestamp to the EEPROM

Conclusion Box is under budget (weight and cost) Program has been tested and is in working order Impact, vacuum, and thermal testing have passed with flying colors