The UBSEDS17 balloon was built from 50 micron thick PA-EVOH-PE multilayer film and was 1.9 meters in diameter. This is 0.4m more than the usual 1.5m diameter. The larger size meant the longest axis of the balloon and payload combined was more than 2 meters, and so a NOTAM was required and obtained for the launch.

The payload weight was 25 grams, and the free lift was 15.8 grams.

The flight reached 11.4km before the envelope burst, and it landed in Kent.


The tracker was similar to that used for UBSEDS15, but with an additional 400mW amplifier section for APRS on 145.825 MHz. This was never used in flight becuase the balloon did not leave the UK (where airbourne AR is not permitted).


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: 241.5km
  • Great circle distance: 229.0km
  • Flight duration: 4 hours
  • Maximum altitude: 11.5km
  • Countries passed through: gb




Thank you to all listeners who tracked this flight!

Total: 23

Callsign Telemetry Lines Received Longest Path
PB0AHX-websdr nl 373 482.2km
0x17 gb 338 305.0km
G8KNN gb 294 186.8km
G4YHE gb 259 142.3km
G8FJG_v gb 226 131.8km
F5APQ fr 223 270.7km
G1DYQ gb 193 222.8km
G0WXI gb 174 153.8km
NLincs gb 132 286.0km
M0UPU gb 121 324.8km
G8DHE-1 gb 112 78.9km
M0SBU gb 112 40.7km
G1BLO gb 98 140.7km
PE2BZ nl 94 371.8km
G8DHE-2 gb 26 77.1km
g0hdi gb 14 77.0km
M0ZBU gb 13 75.6km
G8FJG_h gb 10 54.5km
M1BXF gb 6 117.7km
SA6BSS se 3 1131.4km
PB0AHX nl 2 483.6km
PD5TON nl 1 326.1km