Second Stratocache flight to take off this weekend

Stratocaching has announced the second near space Geocache flight fro the check republic this weekend.

Launch Date: 25-th November 2014

Launch Time: 8:00 UTC

Launch Location: Czech Hydrometeorological Institute Prague, Czech Republic


Stratocaching is a unique idea combining launch of a stratospheric balloon with a geocaching game. The Czech association Žádná věda (meaning Not a Rocket Science) is goung to launch a special ballon set with a gondola called Dropion that includes 12 flying modules with GPS trackers called Stratocache. The modules (an imitation of maple seed design) will be released in the stratosphere and after they fall somewhere in the Czech republic (hopefully!), a geocaching hunt for Stratocaches will be started.

More info:


  • Balloon Hwoyee:3000g filled with helium
  • Total weight of payload:3000g
  • Chute:Sperachute 72“
  • Estimated Ascent/ descent:5-6 m/s up, 4 m/s down
  • Dropion:1800g, made of styrodur, design inspired by nature (the name originally come from „drop- onion“)
  • Stratocache:93 g, 40cm long, falls down rotating as a maple pod (2,5 m/s), with a GPS tracker Meitrack MT90 (replaced battery pack – Energizer Lithium)
  • Radioseed: 2 of the 12 „maple seeds“ bear a different tracking technology: RTTY+CW tracker

APRSseed:   4of the 12 „maple seeds“ bear APRS trackers

  • Electronic systems:APRS tracker, RTTY+CW tracker, Arduino computer, pyrotechnic system for releasing Stratocaches and balloon cutoff, IP video stream module (IP camera Axis M2014, PoE injector router Microtic), video recording module (GoPro Hero 3)
  • Altitude:the launch of Stratocaches and the balloon trajectory will be limited by a flight plan programmed in Arduino computer based on the wheather conditions (maximal altitude 30.000). The aim is to end the flight within the borders of the Czech Republic

Trackers onboard:


Callsign: OK1OMX – UKHAS RTTY 300Bd, 7N2, 450 Hz shift, freq 437.650 MHz, SSB/USB

OK1OMX-11 – APRS, freq 144.8 MHz


Seed1 – UKHAS RTTY 300Bd, 7N2, 450 Hz shift, freq 437.670 MHz, SSB/USB

Seed2 – UKHAS RTTY 300Bd, 7N2, 450 Hz shift, freq 437.690 MHz, SSB/USB

All the trackers are using CW ID with HAM callsign  in between rtty sentences. Seed1 and Seed2 trackers will transmit in CW (20wpm) altitude and locator also.




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