By February 3, Orbiter had broken the flight duration record of 146 hours and 44 minutes set by Fossett during his first around-the world attempt from St. Louis in January 1997, which ended in Pakistan--although not his distance record of 10,360 miles. But the remainder of the flight was in question. China had refused to permit the balloon to fly over its territory so controllers had "parked" it in slow moving air over the Indus River. If China changes its mind, the balloon can rise directly into the jet stream. But if not, the team was considering whether to try to fly around China (a time--and fuel--consuming maneuver) or to come down in the area of Calcutta, India or in Bangladesh, thereby also establishing a new distance record.
Still waiting in the wings is a team headed by Virgin Group magnate Richard Branson. They experienced a setback on December 9 when the envelope of the Virgin Global Challenger broke loose from the gondola and flew off on its own from Marrakech, Morocco. A new envelope quickly constructed in England by Lindstrand Balloons is now beig tested in Morocco. Another group of hopefuls, crewing the Dymocks Flyer, plans to attempt the feat in the Southern Hemisphere, flying a balloon based on the designs of the National Aeronautics and Space Administration's unmanned high-altitude balloons. They await friendly winds in Alice Springs, Australia.
The history of balloon flight dates to 1783 when two French brothers, Joseph and Etienne Montgolfier discovered that filling a bag with hot air would cause it to rise. They demonstrated their principle at Annonay, France, on June 5, 1783 with an unmanned balloon made of linen and paper. Amazed villagers watched as it rose to an altitude nearing 6,000 feet and landed in a field about a mile away. Just months later, on November 21, Pilatre de Rozier and the Marquis d'Arlandes became the first humans to fly in a manmade craft when they ascended from the center of Paris in a Montgolfier balloon.
Early hot air balloons had to be fueled on the ground (or carry dangerous open fires aloft) and, rather inconveniently, they came back down when they cooled. So they were soon replaced by envelopes filled with buoyant gases, such as hydrogen and helium. These balloons continued to rack up records for long duration flights. Balloons were used by the military as observation posts (and a few fairly futile attempts to drop bombs) and have a rich history of carrying scientific payloads into the upper atmosphere. Indeed, the first astronauts were balloonists who ascended to the edge of the atmosphere in a 1950s program known as the Manhigh Project..
The National Aeronautics and Space Administration operates a Scientific Ballooning Program that has collected data about cosmic rays in the upper atmosphere. Fossett, the only balloonist in the current race with a scientific project, was testing an "aerobot" designed by NASA's Jet Propulsion Laboratory to probe the atmospheres of Mars and Venus.
But when it comes to long-distance flight, gas filled balloons are also limited. As the sun heats the gas in the envelope, the balloon rises uncontrollably and so gas has to be vented; when the gas cools, the balloon sinks and pilots must drop ballast to maintain altitude. Sooner or later, they run out of gas or ballast and the journey is over. The problem was solved in the 1960's when Edward Yost equipped a balloon with an onboard propane burner. This device allows pilots to control the balloon's buoyancy by changing the amount of heat injected into the envelope. His innovation created the present boom in sport ballooning and opened the prospect of an around-the-world flight.