The UBSEDS16 balloon was built from 50 micron thick PA-EVOH-PE multilayer film and was 1.5 meters in diameter. The payload weight, including insulation, was 58 grams. We aimed for 25 grams of free lift to give a slightly higher ascent rate than usual, and the helium fill resulted in 26.5 grams of free lift. This initial float altitude was 10.6km (35,000 ft).

The flight was intended to test the superpressure balloon with a heavier payload. After floating for nearly 4 hours the balloon failed, and it landed in France.


The tracker was built mostly from spares, and used a leftover PCB from UBSEDS10 and 11.


The balloon transmits approximately once every 30 seconds.

UHF 434.6MHz

It uses the error-correcting Contestia 16/1000 mode on 434.612.5MHz USB.



  • Total distance traveled: 546.4km
  • Great circle distance: 526.0km
  • Flight duration: 8 hours
  • Maximum altitude: 10.6km
  • Countries passed through: gb fr




Thank you to all listeners who tracked this flight!

Total: 36

Callsign Telemetry Lines Received Longest Path
G8FJG_v gb 566 319.6km
F1OIL fr 536 292.8km
PE1ANS 514 394.8km
F5APQ fr 493 288.9km
G8KNN gb 474 335.2km
g0nzo gb 466 339.3km
M0MDB gb 465 336.2km
M0CJM gb 460 278.4km
ON6LS be 413 327.8km
PE2BZ nl 410 410.5km
G4YHE gb 407 264.7km
G8IMN gb 402 375.3km
G8ZBJ gb 400 396.5km
PA0RPA nl 389 406.7km
PB0AHX nl 373 420.0km
M6DRS 344
G0TDJ 340 287.3km
G0WXI gb 336 332.1km
G1DYQ gb 332 305.3km
0x17 gb 306 280.2km
M1BXF-SDR gb 292 320.6km
G6SUQ gb 285 173.9km
M1BXF-910 gb 285 301.2km
PE1BIA nl 275 320.7km
PD3T nl 191 336.5km
M0SBU gb 131 57.4km
PE1CME nl 107 406.7km
M1BXF gb 95 200.4km
F59665 fr 94 280.7km
PD5TON nl 50 387.3km
F21061 fr 26 207.4km
G4AIU gb 10 228.9km
jijdaar nl 7 309.1km
M0NRD gb 5 358.5km
G0TDJ-SUWS 3 67.6km
SA6BSS se 1 1260.6km