Luxor tragedy puts safety of hot-air balloons in doubt
Before the Egyptian disaster that claimed the lives of 19 tourists, hot-air ballooning had enjoyed a romantic image of adventure
Until tragedy struck in Luxor, hot-air balloons were most famously associated with the film version of Jules Verne's classic novel Around the World in 80 Days, or the exploits of English billionaire adventurer Richard Branson.
Although a journey by balloon has become one of the images most strongly associated with the film, this iconic symbol was never deployed in the book by Verne himself - the idea is briefly raised but dismissed, as it "would have been highly risky and, in any case, impossible".
However, in the popular 1956 movie adaptation starring David Niven the balloon idea is used, and it has now become a part of the story's mythology.
Hot-air balloons can fly very long distances at extremely high altitudes. On January 15, 1991, one carrying Branson and Sweden's Per Lindstrand flew from Japan to northern Canada, completing 7,671.91 kilometres.
This record was shattered on March 21, 1999, when the Breitling Orbiter 3 touched down in Egypt, having circumnavigated the globe and set records for duration (19 days, 21 hours and 55 minutes) and distance (46,759 kilometres).
Essentially the balloon is a nylon bag - known as an envelope - filled with hot air, which is created by burning liquid propane in a steel burner. More heat makes the balloon rise, less makes it descend. It flies in the direction of the wind.