The experimental solar-powered aircraft Solar Impulse 2 will remain grounded in Hawaii until at least April 2016, according to the latest update from the team. In the process of its round-the-world journey, SI2 has encountered numerous delays due to shifting weather patterns, but this latest hiccup came about due to irreversible damage sustained by the batteries when they overheated on the first day of co-founder André Borschberg’s flight from Japan to Hawaii. The team anticipated some maintenance on the single-seater solar plane while in Hawaii, but it’s become apparent that the battery repair will take more time than is left in the flight season.
Essentially, the batteries overheated because they were overly insulated. As Bertrand Piccard, initiator and co-founder of Solar Impulse, describes in his video statement above, this doesn’t constitute a technical failure of the batteries. Rather, the problem was a misjudgment in how the batteries would work during the rapid ascent gains that the solar-powered craft is forced to make daily. The Solar Impulse is a work in progress, and Borschberg and Piccard each seem to be maintaining their sense of humor about what that means for the plane’s original timeline. Piccard says the second half of the round-the-world flight will commence once the repairs are complete, sometime in April 2016. He remarked that, “making the impossible happen takes more time than the possible… Exploration and adventure is not only when you raise the flag with success but also when you have delays, problems, doubts, and that you have to build up a lot of perseverance and tolerance within the team.”
Given what was at stake, it’s quite amazing that the overheated batteries were able to continue to support Borschberg’s flight. The overheating occurred initially on the first day of the five-day-five-night journey from Nagoya, Japan, to Hawaii. During that time, the mission control team monitored the battery temperatures throughout the flight, unable to do anything else. Each day, Borschberg piloted the aircraft up to 28,000 feet elevation in order to take full advantage of the sun’s power and charge the batteries enough to fly through the night. Evidently, the batteries functioned enough to make this possible, so Borschberg could safely complete the 117 hour and 52 minute world record flight across the Pacific Ocean. We’ll be following the updates in the spring to find out what happens after the repairs are complete and this awesome fuel-free airplane is ready to take off again.
Images via Solar Impulse