The solar powered pico balloons B-11 and B-12 were launched by Leo Bodnar from Silverstone, UK on September 1 and 2 respectively. As of 1238 UT on Monday, September 9 both balloons were still in the air transmitting the amateur radio DominoEX16 data mode on 434.500 MHz USB.
During their record breaking duration flights the two balloons have between them flown over most countries in Europe and are now out of the range of tracking stations. B-11 was last reported over Turkey and B-12 over Ukraine. Both balloons are fitted with solar panels which recharge the on-board Lipo battery. B-12 has suffered a battery failure so only transmits when in sunlight.
Pico balloons are proving increasing popular with amateurs. The small foil party balloons can only carry ultra light balloon payloads, typically weighing less than 100 grams. This presents a challenge to the builders to produce a transmitter, GPS, batteries and antenna that are small and light enough to be carried.
Balloons such as these do not go to extremes of altitude but instead float at between 2,500 and 8,000 metres for an extended period. The 434 MHz transmitters can have a radio range of up to 400 km.
Tracks of B-11 and B-12 http://spacenear.us/tracker/?filter=B-11;B-12
Real-time balloon tracking http://spacenear.us/tracker/
Beginners Guide to Tracking using dl-fldigi http://ukhas.org.uk/guides:tracking_guide