The pilots and support crew for the Solar Impulse are back in Hawaii preparing for the continuation of their around-the-world flight, a flight made purely on solar energy. Andre Borschberg and Bertrand Piccard looked refreshed and ready for second half of their trans-Pacific flight. Last year in July, they flew a marathon 118 hours non-stop from Nagoya, Japan to Honolulu. On that trip the batteries were pushed to their operational limits and overheated. As a result the Solar Impulse team had to reassess how they would proceed: re-engineer the battery insulation and risk the delay and changing weather or postpone the mission until 2016. The decision was obvious. Andre Borschberg told me that the batteries themselves were okay, it was the insulation that prevented them from cooling. As a result the team re-engineered the insulation housing in January. The green tubing in the photo is part of the cooling system necessary while on the ground. After landing, if the batteries aren't cooled the batteries run the risk of damage. The weather pattern will determine the next leg of the flight. During their time in Asia, the team learned that having multiple airport options can make or break a flight plan. Recall, Solar Impulse was supposed to fly from Nanjing, China to Honolulu but instead detoured to Nagoya, Japan. As of this writing, there are four possible West Coast options, Vancouver, British Columbia, San Francisco, Los Angeles or Phoenix, Arizona. There will be two stops in the U.S., one in the central U.S. and one in New York. The plane then continues to Europe and ending its around-the-world flight in Abu Dhabi. There will be two public viewings here in Honolulu. One on March 26 and April 2, 2016. Viewing times are from 10am to 4pm. Consult the Solar Impulse website for details. You can find more photos from today's viewing here. The Si2 is parked in the University of Hawaii hanger at Kalaeloa Airport. The planned departure is on April 15, 2016. In the meantime the crew continues with preparations, taking the plane out for test flights. Earlier this week test pilots (not Andre or Bertrand) flew the plane for 16 hours. We're all excited about this next leg of their journey. Hawaii benefits twice for having the Solar Impulse land here and then eight months later begin its journey from here. Solar Impulse and its theme of #FutureisClean brings attention to Hawaii's clean energy goals which are the most aggressive in the country. Very serendipitous!