1. Junk in a Box Critical Design Review
Frank Becky, Kyle Cummings, Jordan Haines, Villiam Klein,
Matt Peoples, Ryan Scott and Aaron Young
October 18, 2007

2. Mission Overview Mission Statement: Plan to Discover:
Reach an altitude of 30km
Prove it’s possible to capture pictures of stars during the day
Measure the stability of our CCD camera on our stabilization ring
Measure the G-forces in 3-axis
Plan to Discover:
The altitude that stars become visible during the day
Maximum g-forces BalloonSat experiences during flight

3. Requirements Flow Down
Level 0
Goal.1
Our BalloonSAT shall ascend to an altitude of approximately 30 km in order to take stabilized photographs of stars and measure g-forces acting on the satellite throughout the duration of the flight.
Objective.1
Construct a BalloonSAT capable of surviving ascent and decent to approximately 30 km, weighing no more than 800 grams and costing no more than 200 dollars by 9 November
Objective.2
Take and record photographs with minimal noise, from within the BalloonSAT, of stars throughout the duration of the flight, in order to discover at what altitude stars become visible.
Objective.3
Stabilize the camera throughout the flight in order to obtain stabilized pictures.
Objective.4
Measure the g-forces acting on the BalloonSAT, during the flight, on all three axes.

4. System Requirement Derived from S.1
Level 1
System
Requirement
Derived from
S.1
The system shall ensure all other systems survive the flight, in working order, and ready to be flown again. (structure)
Objective.1
S.2
The system shall maintain the internal temperature above zero degrees Celsius. (temperature)
S.3
The system shall capture photographs of the sky at least every five seconds, in order to discover at what altitude stars become visible. (camera)
Objective.2
S.4
The system shall stabilize the camera relative to the movements of the BaloonSAT. (stabilizing system)
Objective.3
S.5
The system shall measure g-forces on the x, y and z axes between zero and six g’s. (accelerometer)
Objective.4
S.6
The system shall ensure that photographs can be captured from within the BaloonSAT. (plexiglass)
S.7
The system shall include a light filter that should cancel out Raleigh scattering. (filter)
S.8
This system shall ensure that all systems and subsystems requiring power are powered. (power)

5. Design
Side View of the BalloonSAT

6. Complete Open Design Diagram

7. Whip Test The Test – Simulate descent conditions Our Goal
Attach Prototype to a rope, and quickly spin exerting centripetal force on BalloonSat
Our Goal
Structure must remain completely intact
BalloonSat must stay attached to the rope

8. Drop Test The Test – Simulate impact conditions Our Goal
Drop BalloonSat from a height of 15 meters
Our Goal
BalloonSat must survive impact, and remain intact
Structure must protect internal components

9. Stair Test The Test – Simulate landing conditions Our Goal
Kick the prototype down a flight of stairs
Our Goal
Prototype must survive tumbling and remain intact
Must protect internal components

10. Cold Test The Test – Simulate flight temperature Our Goal
Place BalloonSat in a cooler of dry ice
Turn on Heater, and HOBO
Record internal and external temp.
Our Goal
Keep internal temp.
above 0°C
Picture taken from “BalloonSAT Overview” presentation (Slide 40)
External temperature
Projected internal temperature
Example Temp. Chart

11. Flight Test The Test – Simulate the entire 90 min. flight Our Goal
Turn on CCD camera, audio/visual recorder, accelerometer, heater, and HOBO
Let components run for 90 minutes
Our Goal
Systems must function together for 90 min.
Components must perform respective jobs
CCD – Take and record pictures every 5 sec.
Accelerometer – Measure and record G-forces
HOBO – Measure and record int. and ext. temp.