Former American astronaut Buzz Aldrin, one of the first men to walk on the moon, has been evacuated by plane from the South Pole for medical reasons.
An association of Antarctica tour operators said that the 86-year-old was visiting the South Pole as part of a private tourist group when his health deteriorated.
A statement said he was taken on the first available flight to McMurdo Station, a US research centre on the Antarctic coast. It described his condition as stable.
The National Science Foundation, which manages the US Antarctic programme, said Mr Aldrin would be flown from McMurdo to New Zealand.
Mr Aldrin became the second man to walk on the moon in 1969 as part of the US Apollo 11 mission.