Jet stream power
The Breitling Orbiter will use its solar power system to reach and maintain its projected altitude but will need the jet-stream winds to push it across the globe. Jet stream currents are shaped somewhat like flattened tubes 300 to 600 miles wide and two miles high. They extend for thousands of miles under the tropopause at an altitude of 5.5 to 8.5 miles depending on the latitude. Speeds can reach 185 mph to 250 mph along the eastern seaboard of the United States and in Asia during winter.
The crew hope to ride two main jet stream currents: the polar jet stream located between N30th and N60th parallels at about 30,000 feet and, more important, the more southerly subtropical jet stream between N20th and N30th parallels, at an altitude of 39,000 feet.