Solar Impulse Ready For Pacific Crossing

The Solar Impulse 2 aircraft and its crew are ready to fly from China to Hawaii, and waiting for the right weather window, which the crew now says won't happen before Sunday. The 5,000-mile leg, which will be the longest nonstop flight on the solar-powered electric airplane's round-the-world trip, is expected to take about five days. SI2 landed in Nanjing on April 21, and since then the crew has been waiting and preparing for the right time to launch.Andre Borschberg, who has been alternating the flight duties in the single-seat cockpit with Bertrand Piccard, will be the pilot.

The fragile aircraft's ability to cope with wind and weather is limited. "We need to fly in calm weather, no turbulence," says Piccard, which makes the forecast crucial to the flight's success. "We really have to plan and organize the flight very well." Borschberg recently returned to Switzerland to deal with some health problems, and Piccard flew two flights in a row. Borschberg is now back in China with the team and ready to fly the next leg when the weather allows. The aircraft's small cockpit is unheated and unpressurized, so the long solo flight will be challenging even if the weather cooperates.