Floating Around the World
Balloonists began setting their sights on conquering vast distances almost from the time the sport was bom. In the 1970s, 10 attempts to cross the Atlantic Ocean by balloon failed before the first success. That success, by Maxie Anderson, Ben Abruzzo, and Larry Newman, was called the Double Eagle II expedition, and it landed in France after taking off from Maine during the summer of 1978.
In the last few years, the race for the ultimate ballooning record, a nonstop around-the-world flight, heated up. These attempts, like others since the 1970s, used a different type of balloon from the recreational hot-air balloon. Because the around-the-world flights would take more than 10 days to complete, the fuel demands of a hot-air balloon with its propane burners was too great to allow it to make it even a fraction of the way.
The solution was a hybrid balloon design that crossed a hot – air balloon with a balloon filled with helium gas. The design, called a Rozier after the first man to fly in a balloon, solved the sticky heat-loss problems of long-duration flights.
How the Hybrid Works
The Rozier balloon uses a bag of explosion-proof helium gas in a large sealed bag that fills the widest part of the balloon (called the “crown”). Below that bag, air can be heated by a propane flame in exactly the same way as a recreational hot-air balloon.
But it isn’t the hot air that does the work. In the case of a Rozier balloon, it is the helium that does the bulk of the lifting, while the heated air is used only to keep the
helium warm and toasty at night, when lower temperatures would normally cause the helium balloon to shrink and lose buoyancy.
By the Book
To test Charles’s Law, which states that when pressure stays constant, lower temperature will reduce the volume of э gas, stuff a helium party balloon in your kitchen freezer. Although the balloon is sealed, the cold temperature causes the vibrating molecules to slow down and cluster closer together, reducing the balloon’s volume. Now take the shrunken balloon out of the fridge and notice how much buoyancy it has lost Once it warms up to room temperature, the balloon will return to its original size and buoyancy, just like a Rozier balloon does in the sunshine.
Remember the lesson Archimedes taught us? In the case of a helium gas balloon, the Archimedes principle means that the larger the helium balloon, the more air it displaces, and that means the more lifting force the helium will create. Well, cold night air causes a helium balloon to shrink, thanks to something scientists call Charles’s Law. In practical terms, Charles’s Law means nighttime temperatures send gas balloons on a beeline for the ground—something that makes a balloon pilot cringe.
In early 1999, at least four groups of balloon enthusiasts prepared separate attacks on the around-the-world record. One of them, the Breitling Orbiter 3, took off from Switzerland on March 1 and headed south into the high-altitude winds near the equator. Nineteen days later, the balloon and its two crew members, Bertrand Piccard and Brian Jones, crossed over Mauritania, North Africa, and the same line of longitude they had departed from in Switzerland. It was the first time a balloon had finished a nonstop flight around the globe without refueling. The last great ballooning feat had been conquered!
In 1982, a California truck driver made news with a gas balloon flight of his own. Larry Walters of North Hollywood filled 45 weather balloons with helium, attached them to an aluminum lawn chair, and took off. Equipped with a pellet pistol, a parachute, a CB radio, and a large bottle of soda, Walters floated to 16,000 feet in the middle of busy airline routes. An airfine pilot reported the floating lawn chair to air-traffic controllers, who alerted police. When Walters started to get numb from the cold and the thin air, he used the pellet gun to shoot some balloons and begin his descent On landing, his contraption got tangled in power lines and caused a neighborhood-wide electrical blackout The FAA fined Walters $4,000 for operating without the proper paperwork and for not staying in radio contact with air-traffic controllers. Don’t try this at home, kids!