Planning and Equipment
We use multiple websites and Google Earth for plotting trajectories for the balloon paths.
Astra Planner - Trajectory planner
HabHub Tracker - Trajectory planner
High Altitude Science - Store and helpful guides.
Burst Calculator - Good in planning for ascent rates and max altitude
S3Research - Trajectory planner
Aviation Winds aloft - With practice, you'll be able to read the wind forecast and predict approximate landing locations
Skyvector - FAA maps showing airports and restricted areas to avoid.
Helium - we use a 110 cubic foot tank. On our recent flights, we have used the whole tank, earlier flights we only used partial. It was difficult to gauge the remaining helium, so unless your planning a party, I wouldn't count on being able to launch two balloons with one tank this size. Our local AirGas gives us the student rate. With tax, the total is $110.
Balloons- We used 600 gram and 800g for the first two flights. The last three flights have used 1000g balloons which allow for more lift and a heavier payload.
Payload & Equipment
Our standard payload includes two GoPro camera (1 with an extended battery pack) and a smaller Mobius camera. We have two GPS systems for tracking. One commercial Spot Tracker with amazing accuracy. When you navigate to the spot, the accuracy seems within a few meters. You may have to look up (Flight 4 got stuck high in a tree right above the GPS tagged location). We also use a TrackSoar which transmits location, altitude, pressure, temperature and humidity every minute using the APRS radio system. We have an extra local antennae for picking up the location when we are on the ground. Additional payload items have included a Theta 360 camera for one flight and a stuffed animal and other small mementos.
The first two flights used small styrofoam boxes for insulation. After that, we began 3D printing the capsule to include Go Pro mounts. Sometimes this shatters on impact but Flight 4 & 5 survived nicely and we have been reusing. Our total payload weighs about 1800 grams on the most recent flights.