Cluster Ballooning: “I’ve flown helium cluster balloons nine times over the past several years, making me the most active among the three or four people worldwide

who have ever flown cluster balloons (see History and Technical Notes). A summary of my flights follows, along with links to photographic

accounts of some of the individual flights.” He’s been as high as 21,400 ft., with bottled oxygen and Air Traffic Control clearance. His next flight over the Sierras this summer will be used in a video using ballooning to teach math and science concepts to schoolchildren.