Kenn Borek Air has launched a rescue flight to Antarctica to evacuate a member of a research crew who is in medical need, according to the National Science Foundation.

The Twin Otter aircraft left Calgary early this morning on the first leg of the intercontinental flight, and it will take a few days for it to reach its destination.

The mission will be challenging, as it is currently mid-winter in Antarctica and flights normally do not take place at this time of year due to extreme cold and darkness.

The plane is able to land on skis, as there is no runway at the pole and the landing must be made on compacted snow.

A person at the Amundsen-Scott South Pole station needs more medical attention than can be given at the site. No further information on the patient or the nature of the medical problem is being released to protect patient privacy.

This isn’t the first time Kenn Borek Air has come to the rescue in Antarctica, having performed two previous missions in 2001 and 2003.

The research station is one of three year-round stations operated by the National Science Foundation in Antarctica. There are 48 people wintering at the station conducting scientific observations.