We knew that the solar-powered Solar Impulse 2 — currently on an almost literally Icarusian flight around the world — was badly damaged on its record-breaking flight from Japan to Hawaii last week. But today we learned that the extent of the damage is so severe it will ground the craft until next year.
In a blog post on their website, the team behind Solar Impulse explained the bad news. The damage was incurred on the July 2 flight, which took pilot André Borschberg on an unbelievably long flight from Nagoya, Japan, to Hawaii, breaking the record for longest non-stop solo flight at 117 hours and 52 minutes. But during takeoff and ascent leaving Japan, the batteries that store the precious solar energy that powers the craft were badly damaged:
During the first ascent on day one of the flight from Nagoya to Hawaii, the battery temperature increased due to a high climb rate and an over insulation of the gondolas. And while the Mission Team was monitoring this very closely during the flight, there was no way to decrease the temperature for the remaining duration as each daily cycle requires an ascent to 28’000 feet and descent for optimal energy management.
Because the batteries were over-insulated, the team wasn’t able to cool them down during flight. Why did this problem only rear its head now? In the post, the Impulse team says that the problem is actually an engineering flaw on their part — not a problem with the tech itself. “The temperature of the batteries in a quick ascent / descent in tropical climates was not properly anticipated,” they explain. So the heat of Nagoya wasn’t designed for — and that’s why the batteries couldn’t offload the extra heat.
Now, the team will have to replace the damaged batteries while the craft is grounded in Hawaii — it’s staying at a hangar owned by the University of Hawaii — for months. When will Solar Impulse 2 fly again? It will make the trip to the West Coast, and then onto JFK, in “early April”. It’s a bummer, but an eight month layover in paradise seems like a small silver lining for the team, doesn’t it?
[Solar Impulse; BBC]