The new generation of gas balloons made its first flight in Sept 2010. The Cameron GB1000 flew in the Gordon Bennett Race a few days later, successfully landing after 82hrs simply due to poor weather conditions; however this balloon had enough duration to fly for a further 24hrs. The ground-breaking yet simple design sets a new standard for safety and performance.
The balloon is a totally sealed system, so that the hydrogen remains pure and does not come into contact with air at any time during the flight. By preventing gas and air mixing, combustion is prevented, even if a spark should occur. The GB1000, like all hydrogen balloons today, is constructed from conductive fabric to prevent the occurrence of sparks and care must be taken that all ropes, webbings and accessories are also conductive.
A completely sealed balloon must have provision for pressure release and this is achieved by the servo system. When the balloon is full, instead of allowing an overflow of gas through a fabric appendix tube at the base, the servo pulls on the valve line allowing hydrogen to exit at the top. The metal gas valve has a chimney extension where ignition, should it occur, would not be a problem. This is the only place where gas and air can mix.