We are using a 1600g balloon, which will have a 43′ diameter when it finally bursts. Our payload capsule, fully loaded with 1 SainSonic AP510 APRS tracker, 1 SPOT tracker, 2x Go Pro3+ cameras and the Rocketman 4ft parachute is weighing a little under 700g.
Velocity, altitude and Gas details
Assuming a 700g weight and a 4m/sec ascent rate, our calculations show us that we should be able to reach 127,500 ft of altitude in 162 minutes (does not include descent time) using 99.6 cubic ft of helium with a total lift of 1295g.
We will be using a Sainsonic AP510 APRS Ham radio tracker as our primary tracking mechanism. This will be configured to broadcast location, altitude and temperature every 1 minute for the duration of the flight. As a backup, we are including a Spot GPS Satellite tracker that will report a location every 10 minutes.