High Altitude Photographic Balloon This Project was submitted to Parallax by Earl Foster. I have been working on this project for over 9 months now and it is finally complete. The launch will occur on Saturday August 26, 2006 at Lake Whitney State Park. Lake Whitney has a small dirt landing field next to camping sites that makes for an easy morning launch. As long as the President is not at his Crawford ranch, the launch will occur at or near sunrise. The primary mission of the launch is to take pictures of the curvature of the Earth showing the thin layer of upper atmosphere that separates us from the darkness of space. Primary Flight Computer The PFC is a Parallax BS2px and is responsible for reading and recording latitude, longitude, time, altitude, internal capsule temperature, external capsule temperature, and taking pictures. Additional responsibilities include managing memory storage, relay controls, and audible signals. Text Version Stamp Version. The program flow process is simple: Initialize computer system; Check for manual resets; Get GPS data; Parse string and extract pertinent information; Read internal and external temperature; Check memory allocation; Storage information if space available; Evaluate altitude; Determine if picture can be taken; Toggle relay; Start over again. The program has many debugs that I could remove but decided to leave them in so I could watch the process while connected to a PC. I tried to optimize sub procedures and variables based on my coding ability. I am sure a more experienced coder could do better but I am happy with the results. Secondary Flight Computer The SFC is a Parallax BS2p24 and is responsible for reading GPS data and displaying this information to an LCD. The LCD is powered during testing and pre-launch activities to verify GPS data acquisition. Additional responsibilities include activating external signal lights when the capsule is below 1000 meters. I used oversized high output LEDS that are setup in a rotating fashion. This way I could maximum the current output without exceeding the Stamps current thresholds. The SFC also provides visual indication that the PFC is working through the use the Primary Flight Computer Active Indicator (PFCAI) light. The PFCAI toggles on and off each time the PFC competes a full cycle of the flight program.