Antarctic Mercy Mission: Part II

A daring rescue mission is underway Wednesday to airlift a sick woman from the coldest place on earth — Antarctica. Jerri Nielsen, the doctor at a research station in the South Pole, has breast cancer.

In July, a U.S. Air Force crew dropped medical supplies in a risky nighttime mission in subfreezing temperatures. Mostly intact, the supplies reached their patient who is also the only doctor at the station.

This time, two planes equipped with skis left from Scotia, New York and will crisscross much of the globe stopping first in California and Hawaii. After refueling, the crew will fly across the Pacific to Pago Pago in the American Samoa then on to Christchurch, New Zealand.

They are scheduled to reach the base on October 12th. From there, one plane will fly to the South Pole to retrieve the woman.

The flight path of the rescue mission planes.

Nielsen may be very ill, if the timing of the mission is any indication, reports CBS News Correspondent Jerry Bowen, who joined the Air Force crew on the July mission.

Normally, the South Pole skiway would re-open around the 25th of October. The fact that the National Science Foundation requested a medical emergency evacuation situation ten days earlier would suggest Nielsen may not be doing as well as her doctors stateside had hoped.

She is undergoing chemotherapy treatment, but there are serious side effects. She has nausea and her hair has fallen out.

This latest mission will be more dangerous than the last in that it will be a landing at the skiway.

Added to that are the normal, very difficult conditions at the South Pole, with an almost two-mile high elevation and extreme cold. Average temperatures in the winter are around 80 below.

The temperatures are very important, because at 50 below or warmer, itÂ's considered safe to go in. Any colder, then you have the potential problem of hydraulic fluids freezing up, so you could land but not be able to get off the ground safely.

On this mission, they will land and keep the engines running, as they normally do. Ideally, the doctor will get on the aircraft, theyÂ'll get off the ground as quickly as possible, get her back to Christchurch and stateside as soon as they can.