UK Schools have successfully launched 25 balloons transmitting on 443 MHz.
The launch took place at RAF Cosford, with each attached payload containing a Raspberry Pi and tracker telemetry transmitting on a frequency range of 434.010 to 434.790 MHz.
TV Presenter Jason Bradbury, 2E0JAB took part in the launch, his balloon reached 33km before bursting. Bradbury’s balloon was found stuck in a tall tree!
Pi In The Sky telemetry board - http://pi-in-the-sky.com/
Sent into Space - http://sentintospace.com/