Solar Impulse 2 had been due to leave Nagoya, central Japan, at 2.30 am bound for Hawaii, on the latest and most ambitious leg of a bid to circumnavigate the globe using only the power of the sun.
But after a few agonizing hours poring over meteorological charts and forecasts covering the next five days and five nights during which the flight was scheduled, mission chiefs pulled the plug.
“The flight was cancelled because of the weather around Hawaii,” project spokeswoman Elke Neumann told reporters in Nagoya.
“It's a cold front,” Neumann said.
“The priority is the plane's safety and the pilot's safety.”
Speaking on a webcast moments after climbing out of the plane's cockpit, pilot André Borschberg admitted he was “terribly disappointed”, but conceded it was the right thing to do.
“We were looking to find a way to make it, but I think it is reasonable not to exceed certain limits,” he said.
“The weather is so unstable over the Pacific.”
The featherweight flying machine was not supposed to land in Japan on its multi-leg trip around the globe, but bad weather en route from Nanjing in China to Hawaii forced a diversion at the start of June.
Ever since, the crew has been scouring long-range forecasts for an opportunity to restart its record-breaking journey.
A chance to do so appeared to have presented itself on Tuesday.
“We finally feel like we have a window to Hawaii in front of us. It will be confirmed at 12.00PM UTC! (GMT)” tweeted Borschberg earlier in the day.
Take off was scheduled for the pre-dawn hours because wind tends to be calmer before sunrise, Neumann told AFP.
“The batteries are full so the plane can fly any time,” she said.
“Since the sun comes up very early in Japan, we are flying early . . . we fly much earlier, so we have much more time in the air.”
Borschberg, a 62-year-old Swiss, set a world record for endurance flight in a solar-powered airplane on the trip from China to Japan, logging 44 hours.
The journey to Hawaii was expected to last at least 115 hours, and with nowhere to land after leaving Japan, was considered the most risky so far.
However, Borschberg and his fellow mission chief Bertrand Piccard said they would not let Wednesday's setback deter them, and vowed to try again.
“Solarteam is now looking for new windows to fly to Hawaii,” @solarimpulse tweeted.