Payload system development for high altitude balloon

A balloonSat weighs up to around 4 kg and soars up to reach altitudes of 100,000 feet or higher using a high altitude balloon with its diameter of 10 to 12 feet mostly, but costs only several hundred dollars. This altitude of the stratosphere provides harsh conditions of tough and significant scientific and engineering challenges. High-altitude balloons can carry small payloads to altitudes higher than 80,000 feet into the stratosphere, in which part of space the conditions and atmosphere are quite similar to those in low-Earth orbit, so as to call it as near-space. In this balloonSat project, the payload systems are developed based upon a cubic satellite, which is equipped with a 16-bit microcontroller; wireless 2.4 GHz modem that transmits signals well to a receiver on the ground consistently upon various cosmic radiation levels in the near-space; the 9-degree sensor that collects and transmits in real time during the whole flight. In the meantime to track the BalloonSat throughout the whole flight so as to recover it safely, the GPS and Automatic Position Reporting System (APRS) are deployed with the balloonSat.