Passengers on board a research ship trapped in Antarctic ice for a week are pinning their hopes on a helicopter rescue after three icebreakers failed to reach the paralysed vessel.
The 74 scientists, tourists and crew on the Russian ship MV Akademik Shokalskiy, which has been stuck since Christmas Eve, were hoping the Australian icebreaker Aurora Australis would be able to get through the thick ice and allow them to continue on their way.
The Aurora came within 12 miles of the ship yesterday, but fierce winds and snow forced it to retreat to open water.
Today the weather remained bleak and the crew on the Aurora said the vessel would also be at risk of getting stuck if it made another rescue attempt, said the Australian Maritime Safety Authority.
A helicopter on board a Chinese icebreaker, the Snow Dragon, will now be used to collect the passengers. The Snow Dragon, which is waiting with the Aurora at the edge of the ice pack, was also unable to crack through the ice, as was France's L'Astrolabe.
But the helicopter must wait for a break in the weather before it can attempt a rescue and conditions are not expected to improve before tomorrow, the maritime authority said. The passengers will be flown back to the Snow Dragon in groups of 12, and then transferred by barge to the Aurora.
All 52 passengers will be evacuated, but the crew on the Akademik Shokalskiy will stay behind with the ship and wait for the ice to break up naturally, expedition spokesman Alvin Stone said.
A simple shift in the wind could free the ship. Winds from the east have been pounding the ship and pushing the ice around the vessel. A westerly wind would help break up the ice, Mr Stone said, but no one knows when the wind will change.
The Akademik Shokalskiy, which left New Zealand on November 28, got stuck on Christmas Eve after a blizzard pushed the sea ice around the ship, freezing it in place about 1,700 miles south of Hobart, Tasmania. The ship is not in danger of sinking and there are weeks' worth of supplies on board, but the vessel cannot move.
The scientific team on board had been recreating Australian explorer Douglas Mawson's century-old voyage to Antarctica and expedition leader Chris Turney had hoped to continue the trip if an icebreaker managed to free the ship. The looming helicopter rescue means the expedition will have to be cut short.
Still, Mr Stone said, those on board appeared to be taking it all in their stride. "Surprisingly, all the passengers seem to be considering it the adventure of a lifetime," he said.