During the winter of 1995, Richard Branson and Per Lindstrand will attempt the non-stop circumnavigation of the world by balloon. They will attempt to use the winds to carry them across two oceans and three continents in approximately eighteen days.
Branson and Lindstrand were the first cross the Atlantic Ocean (Balloon Life August, 1987) and then the Pacific (Balloon Life February, 1991) in a hot air balloon. Going around the world by balloon will necessitate sustaining a flight of between eighteen and twenty-one days duration, testing the team’s ingenuity and endurance. For this latest challenge Branson and Lindstrand will be joined in their pressurized capsule by a yet unnamed third crew member. This will enable one member of the crew to sleep at all times.
One additional, and major, change for this flight will be the balloon itself. In 1987 and 1991 the team used hot air balloons for their record breaking flights, but the problems inherent in building a hot air balloon capable of remaining aloft for such a long journey made it necessary to consider the alternative of a helium filled balloon to achieve global success.
However, night time cooling of the gas would unfortunately cause such a balloon to
descend out of the jet stream, which is the only reliable method of maintaining the
speed necessary to make the flight possible. Branson and Lindstrand will instead use a
combined gas/hot air balloon.
First developed by Jean François de Rozier in 1785 the concept of heating captured gas to sustain lift at night has only recently been proven practical by rival balloon manufacturer Don Cameron.
Lindstrand has developed his own refinements to Rozier’s two hundred year old invention. The Rozier balloon will use helium, which will be kept warm with propane burners during the hours of darkness to maintain altitude and speed by remaining in the jet stream.
The Rozier principle, as it is known, will provide a controllable method of sustaining a flight of such long duration. It will also alleviate the need to carry vast amounts of ballast that a pure helium balloon would need for the seemingly impossible amount of fuel required for a giant hot air balloon. In recent years the Rozier balloon has proven itself suitable for such a long distance flight.
Commenting on the project Richard Branson said, "I believe this is the last great aviation record and adventure left on earth. The project is in the spirit of Jules Verne and there would be special significance in bringing the record to Europe before the Millennium. We will attempt to circumnavigate the globe using only the forces of nature-the wind-to propel us around the world in about eighteen days. We appreciate that there are others ahead of us in the race to develop the right type of balloon but we are confident that with the help of British Industry we can catch up. What a wonderful spectacle it would be if we could persuade all the balloonists to take off on the same day and turn it into a race."
Per Lindstrand added, "Richard and I have been through many adventures together but this is the ultimate challenge. We will travel around 20,000 miles [50,000 km] using only the jet stream winds at over 30,000 feet [8 km] to propel us at speeds up to 250 mph [380 km]. This hostile environment will test stamina to the limit, but it will also use the latest technology in materials for both the balloon envelope and the capsule in which we will live for over two weeks. Paradoxically, although we believe that the latest technology has made this attempt possible, the concept of our Rozier balloon is over 200 years old and our flight has been a dream of people for almost as long."
Richard Branson’s Virgin Group of Companies is providing the major backing for the project. The project is also receiving the technical assistance of a number of leading British companies including ICI Films, Compair Broomwade, Hi Fi Industrial Films Limited, GTS Flexible Materials and CS Interglass. Hilton Corp. has lent Erin Porter to the project to assist with public relations. Ms. Porter, who’s title is Director of Protecol, was the public relations contact for Larry Newman’s Earthwinds attempt at circumnavigation. Richard Branson had been an early sponsor of Earthwinds.
The logistics and equipment testing is presently being conducted. Emphasis is being placed on ergonomics and efficiency of the capsule, together with mechanical and navigational performance. The actual attempt will take place when every element has been tested and when the meteorological conditions promise the best chances of success. The next weather window is from this November to February 1996.
In order to qualify for a global flight the balloon must cross the launch longitude having covered a distance of four radians of the earth which is 25,000 kilometers (13,800 nautical miles). The balloon is not allowed to touchdown anywhere or to pick up fuel, gas or ballast during the flight.
Envelope
Creating a helium envelope one and a half times as high as Nelsons Column (187
feet), capable of retaining 900,000 cu. ft. (25,000 cu. m.) of helium and keeping it there
for three weeks is a major operation never attempted before. The longest a gas balloon
has been airborne for is less than six days. To triple the existing record will require the
latest in fabric design and extreme attention to detail during manufacture.
The envelope uses a high tenacity polyamide fabric as its main structural element. This is coated with a polyurethane compound creating a gas barrier and a block of u.v. light. This fabric on its own constitutes a perfectly adequate material for a normal gas balloon but not for one which is to stay airborne for three weeks. To improve u.v. protection and to further reduce porosity, an outer layer of aluminized Melinex film is added. This material has been specifically developed by ICI and is one of the most efficient gas barriers available anywhere in the world. This laminated material will reduce gas losses from the envelope by a factor of ten and will also serve other functions which Lindstrand declined to reveal.
The joining of the envelope is carried out by thermal welding which avoids the use of any adhesives with the subsequent environmental hazards. The welding process must be carried out very carefully as a single hole about the size of a pin head could lose the balloon 3-4 days of endurance. Once the manufacture of the Global balloon envelope starts, the assembly hall takes the appearance of an operating theater using clean room technology.
The fabric for the Global balloon has been developed specifically for this flight. Since it is likely that a flight test of the envelope would not survive a landing without damage, and the very high cost of filling it with helium, the envelope material is being tested in simulated conditions as near as possible to actual flight.
INSTRON materials test system, the world’s largest supplier of materials testing equipment, is conducting analysis on the balloon fabric properties.
One factor in the testing is that this balloon will fly at altitudes and temperatures that no other fabric balloon has ever flown in and it will also be exposed to the violence of the jetstream and accelerated into speeds in excess of 200 knots. An environmental chamber will place the fabric under test conditions from -70 C to +330 C. The tensile jaws are driven by a computer and will simulate two weeks of flight in the jetstream at the correct temperatures and fabric stresses in the lab.
Capsule
In order to fly in the jetstream the balloon must be able to sustain flight at the 30,000
foot level. Human life could not exist at this level without either breathing 100% oxygen
or by creating a pressurized environment. While breathing 100% oxygen through a
mask will give one the required oxygenation of the blood, other medial factors resulting
from the lack of pressure on the body would bring great discomfort after 4-5 hours and
is not practical for a long duration flight.
To pressurize the capsule, a system has been created like that of an airliner where air is pumped into the cabin continuously and where the pressure inside the cabin is regulated by an outflow valve. A special air pump has been created and will be run by a propane powered piston engine on top of the capsule. Air will be taken from the atmosphere and pumped in under high pressure to the cabin. This is a continuous process throughout the flight. The outflow valve regulates the internal pressure to a constant 8,000 ft level. The air coming out of the compressor is +165 C; a series of intercoolers are used in order to adjust the air to the correct temperature.
Since the system is crucial for flight above 12,000 feet, two identical engines/compressors are fitted to the capsule and both are run at half speed during the flight. In case of a failure of any unit, the remaining one can speed up and carry the entire load.
The balloon will carry VHF (Very High Frequency), HF (High Frequency) and satellite communications capabilities.
The Weather
The weather, or rather the aerodynamic forces created by the weather, is what
propels a balloon. By definition, a balloon is an aerostatic vehicle incapable of
maneuvering horizontally by its own force.
The strongest force of weather is a hurricane and represent the greatest danger of the project. Hurricanes, which could occur during the flight, typically develop in the Philippines and around Florida. Hurricanes can develop from nothing to full blown strength within 3-4 days.
The second strongest force created by the weather is the jetstream, which is a creation by cold polar air descending south and colliding with moist and warm tropical air. In the interface of these two air masses, the air is squeezed eastwards at a very high speed creating what we call jet streams. Their width can vary considerably, say from 50-100 miles, but they are rather thin, normally only occurring in the tropopause between 29,000 and 37,000 feet.
Jetstreams are charted by the Met Office using a variety of information such as weather satellites, airplane reports, met balloons and Doppler radar. The Global team will receive detailed weather charts in the capsule moments after they are released by the Bracknell Weather Center.
Many components and elements will need to work for a circumnavigation of the globe to be successful. Lindstrand and his team are currently testing and refining their system. In September Henk Brink unveiled his Cameron built Rozier in a hangar at the Kennedy Space Center in Florida.
Who will be first in the air and successfully complete the long journey is anyone’s guess at this point. The task involves extensive planning and a strong dose of good luck.
