Just days after announcing the plane would remain in Hawaii for several more weeks because of damage to its battery packs, officials with the Solar Impulse team now say the issue has grounded the aircraft at Kalaeloa until at least April of 2016.
Last week, members of the Solar Impulse team said that the aircraft had sustained irreversible damage to its batteries during the record-long flight from Nagoya to Kalaeloa because of an overheating issue. Team leaders say the overheating issue was being monitored during the flight, but there was no way to address it once the plane had taken off. Insulation in the battery areas is also believed to have added to the problem.
Post maintenance test flights are expected in 2016 with the resumption of the aircraft's attempt to go around the world powered only by solar energy continues.
"Overall the airplane performed very well during the flight," the Solar Impulse team said in a statement. "The damage to the batteries is not a technical failure or a weakness in the technology but rather an evaluation error in terms of the profile of the mission and the cooling design specifications of the batteries. The temperature of the batteries in a quick ascend/descend in tropical climates was not properly anticipated."
Repairs that were initially expected to take weeks are now likely to take months, and the Solar Impulse engineering team says it will be "studying various options for better cooling and heating processes for very long flights."
The Solar Impulse 2 will be kept in a hangar at the Kalaeloa Airport for the duration of its stay in Hawaii, a partnership arranged in part by the University of Hawaii and the state Department of Transportation.
"Post maintenance check flights will start in 2016 to test the new battery heating and cooling systems," the Solar Impulse team said. "The round-the-world mission will resume early April from Hawaii to the USA West Coast."