icebreaker was sailing to Antarctica on Sunday in a rescue mission to evacuate a researcher with a «developing medical condition» from a remote station.
Icebreaker RSV Nuyina departed from Tasmania last week to rescue an unnamed individual from Casey, a research base on the frozen continent 3,443 kilometres (2,139 miles) away, the Australian Antarctic Programme said.
The researcher «requires specialist medical assessment and care in Australia for a developing medical condition», a programme spokesperson said.
The name of the condition was not given.
The ship has a top speed of around 16 knots, meaning the rescue could take several days.
The Nuyina was equipped with helicopters on board to help the evacuation effort, the spokesperson said in a statement Saturday.
The researcher's family is being kept informed of the situation, the statement said, adding that «the wellbeing of our people is our highest priority.»
There is an aerodrome 70 kilometres (44 miles) from Casey, but it can only be used during the southern hemisphere summer months due to extreme weather, the Australian Antarctic Programme said.
Up to 160 researchers visit the base at Casey in summer, according to its website, but only around 20 people remain on the station during the winter months.