Listen live as solar airplane crosses U.S.

The Solar Impulse, a solar powered airplane that Swiss pilots Bertrand Piccard and Andre’ Borschberg hope to fly around the world without using fuel, is crossing the United States. The airplane is flying today from Dallas to St. Louis using only the energy of the sun for propulsion. The flight can be watched live on the internet at the SolarImpulse.com. The team plans to land in St. Louis in the early morning hours of June 4.

The plane was disassembled and transported to Moffet field in Mountain View, Calif. earlier this year. From California, the Solar Impulse began its journey across America on May 4. The first leg consisted of a flight from Moffet field to Phoenix Sky Harbor airport in Arizona, a distance of approximately 550 nautical miles. The Solar Impulse made the trip in 18 hours and 18 minutes for an average speed of about 40 miles per hour. The average altitude was 10,000 feet, but the plane flew as high as 21,000 feet on its trip to Phoenix. The 18 hour 21 minute leg from Phoenix to Dallas took place on May 22.

The Solar Impulse is powered by 12,000 solar cells that are built into the wings. The solar cells power four 10 horsepower electric motors. Because the solar cells also charge the Solar Impulse’s lithium batteries, the airplane can also flight at night or in cloudy weather. To make the Solar Impulse a reality, the team had to make advancements on lightweight solar energy technology, batteries, and decrease the necessary weight of the airplane as well. The Solar Impulse website contains many details about the aircraft itself.

Because of the long and slender structure of the wings and fuselage, the Solar Impulse is very vulnerable to high winds and turbulence. The team typically tries to take off and land and night to minimize exposure to turbulence. The recent severe weather and tornadoes in the Midwest have led the decision to park the airplane in an inflatable hangar during its stay in St. Louis for protection.

The current Solar Impulse, the HB-SIA, will be replaced by the HB-SIB for an attempted flight around the world in 2015. The HB-SIB will have several improvements over the HB-SIA. Performance will be better and there will be a larger cockpit to accommodate the pilot for flights lasting several days. The HB-SIA has already set three world records for maximum altitude (30,298 feet/9,235 meters), gain in altitude (28,687 feet/8,744 meters), and maximum duration (26 hours 10 minutes 19 seconds).

The founders of the Solar Impulse program are Bertrand Piccard and Andre Borschberg. The two Swiss pilots have worked on the program for more than a decade. Piccard is a psychiatrist by profession, while Borschberg is a mechanical engineer.

Originally published on Aviation Examiner