MM21B - 2019-05-23

Tracker Details

Tracker Type: APRS

Model: PicoTracker1Rev2

Powered by 2 AAA batteries


gpsLockTimeoutMs = 150000 (150s, 2m, 0h)

gpsRetryAfterMs = 10000 (10s, 0m, 0h)

transmitCount = 2

msBetweenTransmits = 3000 (3s, 0m, 0h)

lhAltFtThreshold = 10000

hAlt.wakeAndEvaluateMs = 180000 (180s, 3m, 0h)

lAlt.wakeAndEvaluateMs = 50000 (50s, 0m, 0h)

lAlt.stickyMs = 24000000 (24000s, 400m, 6h)

dz.wakeAndEvaluateMs = 7200000 (7200s, 120m, 2h)

Launch Parameters

Balloon and Payload

  • 36" Qualatex
  • 30.1 gram payload
  • 1.98 grams free lift



Miles traveled: 1,218

Flight hours: 68.5

Max Altitude feet: 18,843

Cause of death: Slow leak

General Thoughts / Observations

This flight’s theme was to reach Mississippi and also to test a 5/4 wave transmission antenna. The balloon did make it to Mississippi and beyond, the 5/4 wave antenna did not prove to be a better antenna than the 1/2 wave.

On May 23, 2019, MM21B flew out of Florida and into the gulf. After a day of silence, the balloon showed up in Mississippi and started heading northeast. From Mississippi the path formed somewhat of a large arc, it crossed Alabama, Georgia, then slowly descended and landed in South Carolina.

The balloon demonstrated great float for multiple days, why it started to slowly descend is not known. It's possible that under pressure the balloon simply leaked out its free lift over a couple of days.

This longer flight was fun to watch and picked up three new states for the list. It also helped conclude the APRS Antenna Length Test and show that we should stick with 1/2 wave antennas.

Thoughts for next time

Monitor % of missing sequences of future flights, see if the number is consistent among 1/2 wave antennas.