By Michael Roberts
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By Michael Roberts
In recent years, all of the global attempts have taken advantage of improvements in roziere balloons, a hybrid technology that combines the best of hot-air and gas ballooning. Hot-air balloons use propane burners to heat the air in the balloon but are considered unfeasible for long flights because of the amount of fuel required. Gas balloons use a lighter-than-air gas, usually helium, and throw off ballast to rise higher or slow the rate of descent--but their range is limited, too, by the amount of ballast they can carry. Roziere systems use a "cone" of hot air at the mouth of the envelope to heat the helium above, particularly at night, when cool temperatures cause conventional gas balloons to contract and lose altitude, requiring the expenditure of more ballast to keep on course.
With rozieres, global competitors have managed to set new records for distance and duration. Launching from St. Louis and flying solo, Beaver Creek commodities broker Steve Fossett made it as far as India in 1997 and to southern Russia last January. (Fossett, whose low-tech, unsponsored flights have cost him around $400,000 each, has announced that he will make a fourth try at the circumnavigation record from Argentina within the next week or two.) A Swiss-Belgian team, Breitling Orbiter 2, flew from Switzerland to Burma earlier this year, staying aloft for an unprecedented ten days before running out of fuel.
"We're nearing the apex of the learning curve," says Roark of Team Re/Max. "Sooner or later, somebody is going to figure out how to do it. What with Fossett going halfway around on his second try and getting all the way to Russia last time, it's becoming evident that somebody's going to do it, and it's going to happen fairly soon."
But the roziere crowd has had its share of setbacks, too. Richard Branson's Virgin Global Challenger, probably the best-financed of all the ventures, has been plagued with equipment failures. This year two American attempts were aborted within hours of their launch when their helium cells burst as they ascended. Other flights have been cut short by treacherous launch conditions, icing, leaky fuel lines, fuel exhaustion caused by having to maneuver out of the way of storms or countries that refuse overflight permission, and so on.
Does that mean that Liniger's stratospheric venture has an edge over the others? "It's a tough race to handicap," says Tom Hamilton, editor of Balloon Life magazine. "All of these guys are inventing the wheel. We haven't worked out the technology for that long of a balloon flight yet."
Hamilton, whose publication has a circulation of 3,500 and caters to the true enthusiasts of the sport ("Special Report: Power Line Avoidance"), says the race comes down to three factors: weather, equipment and experience. Assuming a successful launch, Team Re/Max has the weather factor licked, he says; there's not much weather, or anything else, at 130,000 feet.
But a stratospheric flight also requires more specialized equipment, he notes: "To take a balloon to that kind of altitude puts a lot more demand on the system, and every one of these projects has failed because of an equipment problem of some type."
As for the human factor, Hamilton gives the nod to Branson's Virgin Global Challenger and Fossett's Solo Spirit. "If you look at the expertise involved, Branson's team you have to rate pretty high," he says. "You have to give good marks to Fossett, too; he certainly has the experience now, probably more than anyone else in long-distance ballooning." For Team Re/Max to succeed, he adds, "it's going to take a tremendous amount of mental and physical ability."
And maybe some dumb luck. Liniger and his associates will benefit from NASA's long experience in stratospheric ballooning--they will use the same kind of envelope NASA uses, and their support team includes several key figures involved in the operations of the National Scientific Ballooning Facility. But even with all the testing of its equipment the group plans over the next few months, some questions will remain right up until launch time. For example, the soundness of the envelope itself, which is made of a thin polyethylene film and will expand to an astonishing 39.5 million cubic feet at cruising altitude, can't be tested in actual flight conditions beforehand; because of the nature of the material, it can be inflated only once.
"To an extent, its first flight is its test flight," says Bob Martin. "We can only fly it one time. But I think the tests we have planned will give us a high confidence factor."
Just getting the balloon off the ground will be no mean feat. Standing the massive envelope up--nearly 700 feet tall at full expansion--in any kind of surface wind will be tricky and will require an experienced launch crew. NASA has launched several balloons from Australia without incident, but then, not even Liniger has NASA's resources. "If NASA tried to do what we're doing, it would cost half a billion dollars," Roark says.
The graver dangers, though, await the team in the stratosphere. Their lives will then be in the hands of the life-support equipment in the gondola, which resembles Gemini-era technology rather than space-shuttle sophistication. The air in the tight quarters must be scrubbed constantly in order to prevent buildup of carbon dioxide, the oxygen levels constantly monitored, excess humidity reduced by a condenser cooling system. Reflective paint, special insulation and the aeronauts' own body heat should help to buffer the temperature extremes, but even the project's "gondola operations director" says it won't be a comfortable ride.