(CNN)[Breaking news update, published at 5:56 p.m. ET]
A flight that was sent to the Amundsen-Scott South Pole Station to evacuate someone for a medical condition has arrived there, National Science Foundation spokesman Peter West said Tuesday.
The aircrew will rest at the station for about 10 hours before determining when weather conditions will be suitable for a return flight, West said.
[Original story, published at 1:01 p.m. ET]
A medical evacuation flight is underway for an ailing member of the National Science Foundation's Amundsen-Scott South Pole Station, according to a statement by the foundation.
"After comprehensive consultation with outside medical professionals, agency officials previously decided that a medical situation at Amundsen-Scott warrants returning one member of the station's winter crew to a hospital that can provide a level of medical care that is unavailable at the station," the statement said.
The National Science Foundation currently manages the U.S. Antarctic Program. Though the foundation is not providing personal or medical information because of patient privacy, it has identified the patient as someone who is seasonally employed through the Lockheed Martin Antarctic Support Contract. It has also suggested that the flight might bring a second patient back, but the decision hasn't been made.
After it was determined that a flight for a medical evacuation was necessary, two Twin Otter aircraft were deployed June 14 from Canada to South America and then to the Antarctic Peninsula. They both landed at Rothera, the British Antarctic Survey station on the Antarctic Peninsula, Monday and waited for a window of good weather to complete the last 1,500 miles of the journey. One aircraft will remain at Rothera to provide search and rescue capabilities while the other retrieves the patient.
The flight to Amundsen-Scott left this morning and is expected to arrive at 5 p.m. EST.
Even though flights are discouraged between February and October due to the extremely cold and dark conditions of mid-winter Antarctica, the pilot, Kenn Borek, has flown in similar conditions during evacuations in 2001 and 2003.
The aircraft, driven by two propellers, are designed to fly in extremely low temperatures and land on skis because there is only compacted snow, no tarmac, and the landing could happen in total darkness. That's what makes this particular mission so dangerous. Right now, only the moon and the aurora australis provide natural lighting. Previous July temperatures have dipped as low as minus-76 degrees Fahrenheit.
There are 48 people at Amundsen-Scott, one of three year-round stations operated by the National Science Foundation in Antarctica. Researchers there are studying the atmosphere and dark matter using two radio telescopes, as well as an observatory that monitors subatomic particles produced by black holes and other cosmic incidents.
Multiple agencies and nations will assist with the evacuation, providing everything from weather forecasts to medical expertise.
Other medical evacuations have taken place in recent years at Amundsen-Scott and 850 nautical miles away at McMurdo Station. Both flew to New Zealand for medical care that is not provided at the station.
Americans have continuously occupied the South Pole for research purposes since 1956. Amundsen-Scott was built in 1957 but has been updated and redeveloped over the years.