Former astronaut Buzz Aldrin testifies at a Senate Subcommittee on Space, Science, and Competitiveness, entitled "U.S. Human Exploration Goals and Commercial Space Competitiveness,"? on Capitol Hill in Washington, Feb. 24, 2015. Reuters

Update: 8:59 a.m. EST -- Buzz Aldrin, the second man to walk on the moon, was reportedly in a "stable condition" when he was evacuated from the South Pole early Thursday morning, according to ABC7 Bay Area. The status of Aldrin's health and condition were previously unknown.

Original story:

World-famous astronaut Buzz Aldrin was evacuated from the South Pole Thursday, according to a release by the National Science Foundation. The reason behind the 86-year-old’s evacuation was not immediately known.

Aldrin, who was the second human known to have walked on the moon in 1969 as part of the country’s Apollo 11 mission, posted pictures prior to his trip to Antarctica on Tuesday but why he was traveling there was unclear.

NSF said it received a request from The Antarctic Company - a private tourism business based out of South Africa - to provide a “medical evacuation” for an “ailing visitor.” The release said the NSF agreed to transport Aldrin from its Amundsen-Scott South Pole Station to the McMurdo Station, a U.S.-run research center on New Zealand’s Ross Island.

However, initially, there were conflicting reports and statements. A company called White Desert, which Aldrin referenced on his Twitter account, said Aldrin was their client and said he was visiting with a tourist group until his “condition deteriorated, a release from the International Association of Antarctica Tour Operators said.

The NSF clarified to International Business Times that White Desert requested a charter flight from The Antarctic Company.

Earlier this month, Aldrin joined a number of other top astronauts like Jim Lovell at the Kennedy Space Center in Cape Canaveral, Florida, for the opening of a new exhibit celebrating their achievements.

Aldrin also released a new book in April titled “No Dream Is Too High: Life Lessons From A Man Who Walked on the Moon,” which included stories and advice Aldrin had gathered throughout his life.