CHICAGO — In a spartan capsule equipped with a bunk bed, camp stove, and military rations, Steve Fossett hangs from a large polyester and Mylar bag, at press time, about 22,000 feet above North Africa.
The Chicago securities trader-turned-millionaire-adventurer is on a near quixotic mission to shatter one of the last great barriers in the world of aviation: circumnavigating the globe, nonstop, in a balloon.
It is a feat that has eluded pilots of these unpredictable airships for more than a century. In the past week, two other well-financed expeditions failed.
Mr. Fossett's attempt is a daring test not only of flight skills and state-of-the-art balloon design, but also of mankind's ability to divine the whims of Mother Nature by drawing on computers and meteorological data from a global satellite network.
Historically, long-distance balloonists have been thwarted by two principal foes: violent weather and thermal physics.
At night, the gasses that keep the balloons aloft cool, sending the craft earthward. Crews are forced to jettison sandbags and other ballast to maintain altitude. During the American Civil War, experts say, soldiers in observation balloons sometimes tossed all their clothing overboard to stay aloft while escaping enemy territory.
Come day, the sun heats the gasses again, lifting the then-lighter craft to dangerous heights and forcing pilots to let out gas to stop the balloon from exploding.
This daily cycle of rising and falling, steadily exhausts the supplies of gas - usually helium - and balloonists are forced to the ground within five or eight days, far short of the roughly 20 days required to voyage around the world.
Recently, however, designers at Cameron Balloons Ltd., in Bristol, England, overcame this hurdle by building a helium balloon with a thin, air-filled outer liner. By burning propane to heat the surrounding air layer at night, pilots could stabilize the helium temperature of the inner balloon and prevent the craft from falling.
Fossett's Rozier balloon - a 150-foot-high polyester and mylar craft designed by Cameron and named after the Frenchman who made the first manned balloon flight in 1783 - can technically remain airborne for at least the 18 days he estimates that it will take him to complete his $300,000, self-financed round-the-world trip.
The second, more daunting, nemesis of marathon balloonists is weather.
"The No. 1 weather problem is thunderstorms or convective activity," says Lou Billones, a retired US Air Force colonel and balloonist who is acting as Fossett's chief meteorologist.
Such weather can produce strong wind sheers that can rip the balloon apart, lightning that can strike fuel tanks and cause the balloon to explode, and hail that can shred the balloon and send it plunging, says Colonel Billones.
But two recent advances are helping pilots skirt the dire storms that have felled balloons since Rozier's time.
Pressurized balloon cabins now allow pilots to fly above 30,000 to 35,000 feet and into the stratosphere, effectively avoiding turbulent weather. These cabins were used in two failed around-the-earth balloon attempts earlier this month, one led by the British tycoon Richard Branson and the other by the Swiss doctor Bertrand Piccard. Both flights failed.
On Sunday, the balloon piloted by Dr. Piccard was forced down by a kerosene leak in the cabin.
On Jan. 8, Branson and two crew members brought their Virgin Global Challenger balloon down in Algeria less than 24 hours after taking off from Morocco. For reasons not yet explained, the craft suddenly began to plummet. The team was saved by a daring crew member who climbed out of the capsule and jettisoned two tanks to keep the airship from crashing to the earth.
Unlike the other ballonists, Fossett is flying alone. And Fossett has chosen a more dangerous strategy based less on avoiding the weather than on outsmarting it.
Flying below the stratosphere at 18,000 to 24,000 feet in a chilly, unpressurized cabin, he is relying on twice daily weather forecasts produced by highly sophisticated, computerized weather models. Fossett, who is equipped with a life raft but no parachute, hopes that such forecasts, projected out 10 days, will warn of storms ahead in enough time for him to change altitude and catch a wind stream that will waft him out of their path.
At midmorning Chicago time on Wednesday, for example, weather models detected a storm brewing south of Iceland. "An Icelandic low was forming and we didn't want him to get sucked into that," says Billones, who advised Fossett to raise the balloon up to near 24,000 feet "to catch a more southerly, subtropical jet."
At press time, that shift in course was leading Fossett on a new route over North Africa rather than toward northern Europe and over Russia as originally planned.
"The planned route was always very tentative," says spokeswoman Debbie Herrick at the mission's headquarters at Loyola University in Chicago. "Nothing is set in stone."