A sun-powered plane that has completed nearly half of an unprecedented round-the-world flight, will be grounded for several months in Hawaii to carry out battery repairs, the project says.
"Irreversible damage to certain parts of the batteries will require repairs which will take several months," it said in a statement on Wednesday (local time).
The team said last week that battery temperatures in the Solar Impulse 2 had surged during a gruelling, five-day journey from Japan to Hawaii, and there was no way to cool the battery packs once the aircraft was in flight.
There had been hope that repairs could be completed by next month, but the fixes will take until "early spring 2016."
A spokeswoman for the project separately told AFP that it was possible the battery packs needed to be replaced entirely if the existing system could not be repaired.
"We don't know yet if we have to change everything or if we can repair (the existing material)", but any new parts would have to be produced by the project, she said.
"It's not like you can order them," as the craft is unique, she added.
The aircraft has been flown by Swiss businessman and pilot Andre Borschberg, 62, who has already set a new record for the longest solo plane flight.
His 118-hour journey across the Pacific smashed the previous record of 76 hours and 45 minutes set by US adventurer Steve Fossett in 2006.
His partner, Swiss aviator Bertrand Piccard had been scheduled to pilot the next leg of the journey from Hawaii to Phoenix, Arizona.
The aircraft took off from the United Arab Emirates (UAE) earlier this year powered by 17,000 solar cells, with the project aimed at promoting the use of renewable energy.
Once repairs are completed, the plane is expected to cross the United States, stopping in New York before a trans-Atlantic flight to Europe.
From there, the pilots plan to make their back to the point of departure in Abu Dhabi.