Maritime safety officials began preparations on Tuesday for a helicopter rescue of scientists and others aboard a chartered research ship that has been stuck in Antarctic ice for a week.

The Australian Maritime Safety Authority said all 52 passengers aboard the Russian ship, the Akademik Shokalskiy, would be airlifted to a Chinese icebreaker. The ship’s 22 crew members would stay behind, the authority said.

Bad weather in the area made it very unlikely that a helicopter rescue would begin before Wednesday, the authority said. But in preparation, a landing zone had been marked on the ice near the Shokalskiy.

The 233-foot Shokalskiy became stuck last Tuesday when strong winds pushed loose pack ice up against it near Cape de la Motte, about 1,700 miles south of Hobart, Tasmania. The ship set sail from Bluff, New Zealand, on Dec. 8, and is carrying scientists, tourists and several journalists on what is billed as the Australasian Antarctic Expedition, a planned monthlong voyage to study the changes to the environment of East Antarctica since the region was first explored by the Australian geologist Douglas Mawson a century ago.