DM02 - 2018-04-24

Tracker Details

Tracker Type: APRS

Model: PicoTracker1Rev2

Powered by 2 AAA batteries


  • lhAltFtThreshold = 10000
  • hAlt.wakeAndEvaluateMs = 900000 (900s, 15m, 0h)
  • lAlt.wakeAndEvaluateMs = 45000 (45s, 0m, 0h)
  • lAlt.stickyMs = 10800000 (10800s, 180m, 3h)
  • dz.wakeAndEvaluateMs = 1800000 (1800s, 30m, 0h)

Launch Parameters

Balloon and Payload

  • 36" Qualatex, unstretched
  • 30.8 gram payload
  • 6 grams free lift


Predicted Internal Pressure: 3.93 kPa (whoops, didn't actually check that before launch, too high)

Predicted Altitude: 18,143 ft

1 day prediction

5 day prediction


  • Top Altitude - 16,326 ft
  • Duration - 24 hours, 37 min
  • Distance - 623 miles great circle, 711 miles actual path
  • Cause of death - Seemingly losing altitude and ultimately touching down on the ground

Altitude over time

Speed over time


  • New location - Made it to Canada and crossed over Maine
  • Duration record - 24 hours 37 min
  • Distance record - 623 miles

General Thoughts / Observations

Tracker lost and gained a lot of altitude regularly. At least once it's possible it touched the ground.

Unclear why that would be happening.

There was a storm chasing the tracker, maybe that's part of it.

Not convinced the tracker ever floated for long, as 6 g of free lift probably would pop it, and might actually be the ultimate cause of its death.

Geofencing kicked in, seemed to be working.

Hadn't realized at the time, but the Quebec City area was outside the geofence zone, but due to low altitude the tracker was reporting.

When the tracker gained elevation, it purposefully didn't transmit 9 times, hence the long period at the end of no transmissions.

Managed to actually cross the Canadian border at the actual border crossing checkpoint.

Thoughts for next time

Less free lift.

Don't launch around storm weather.