CNN — UPDATE:
Efforts to rescue a research crew aboard a ship stuck in the frozen seas off Antarctica stalled Thursday after ice conditions appeared to prevent a barge from the Australian icebreaker Aurora Australis from reaching a Chinese vessel, according to the Australian Maritime Safety Authority (AMSA).
The rescue plan called for a helicopter to ferry the passengers from the Russian-flagged MV Akademik Shokalskiy to the Chinese vessel, where they would then board a barge to take them to the Australian ship.
"It is now likely the rescue will not go ahead today," the maritime agency said in a written statement.
Efforts to rescue a research crew aboard a ship stuck in the frozen seas off Antarctica appeared to be a go, with reports weather conditions have improved enough to launch a helicopter to pick up the passengers, Australian maritime officials said Thursday.
If successful, the helicopter lift marks the beginning of the end of a saga that began Christmas Eve after the Russian-flagged MV Akademik Shokalskiy got stuck in 10 feet of ice.
If the rescue begins within hours, it will still be weeks before the research team will make it to Hobart, Australia, John Young of the Australian Maritime Safety Authority (AMSA) said.
"Mid-January is our best guess," Young told reporters on a conference call.
The helicopter, which can transport 12 people each trip, will take the ship's 52 passengers -- who include the research team and journalists -- to the Chinese icebreaker called the Snow Dragon, or Xue Long, the maritime agency said. The 22 crew members of the Akademik Shokalskiy will stay aboard, it said.
The passengers will then be transported by barge from the Chinese ship to the Australian icebreaker Aurora Australis.
The entire rescue operation is expected to take anywhere between five and 12 hours, according to the maritime agency.
"This rescue will be a complex operation involving a number of steps and subject to factors such as weather," said Lisa Martin, a spokeswoman with the Australian maritime agency.
The helicopter rescue follows a failed attempt by the Chinese icebreaker, which made it six nautical miles from the trapped vessel before being stopped by the ice.
That was followed by an effort by the Australian icebreaker, which was forced Monday to suspend efforts to reach the expedition because of bad weather. The Aurora Australis got within 10 nautical miles of the ship before it turned back.
Over the weekend, an effort by the French icebreaker Astrolabe was called off by the maritime agency.
In preparation for the helicopter rescue, members of the research team as well as the crew of the Akademik Shokalskiy marked a makeshift helipad on the ice where the helicopter can land.
Video clips posted online by the research team showed people, with arms locked, walking to tamp down the snow.
"As we understand, the helipad was suitable yesterday and will be suitable today," AMSA's Richard Wallace said.
Once the passengers are safely aboard the Aurora Australis, the ship will complete a resupply mission to Casey Station, an Australian base in Antarctica, before making its way to Hobart, the maritime agency said.
The exploits of the research crew have gone viral, thanks in large part to Twitter and YouTube posts by those aboard the stranded vessel.
Chris Turney, an Australian professor of climate change at the University of New South Wales, has tweeted photos of the stranded ship, the crew and penguins, who he said -- according to one post on Twitter -- "to check out what's going on."
"The group on this ship is incredibly collegiate," said Alok Jha, a science correspondent for The Guardian newspaper, told CNN's Anderson Cooper 360. "There are a lot of skills and things people are sharing with each other."
Turney has said there are regular briefings on the status of rescue attempts, and in the meantime, people are doing what they can to keep busy. That includes yoga and Spanish classes, Jha and Turney said.
The group even managed to ring in 2014 with good cheer.
"We're the A, A, E who have traveled far, having fun doing science in Antarctica!" a dozen or so of them sang in a video posted on YouTube. "Lots of snow and lots of ice, lots of penguins, which are very, very nice!
"Really good food and company, but a bloody great shame we are still stuck here! Ice cold, cha cha cha! Ice cold, cha cha cha!"
-- CNN's Radina Gigova contributed to this report.