John Bacon

USA TODAY

Former astronaut Buzz Aldrin, the second man to walk on the moon, was evacuated Thursday from the South Pole for medical reasons, officials said.

Aldrin, 86, piloted the first lunar landing module to reach the surface of the moon in 1969. He followed Neil Armstrong out the door and into history.

The tour company White Desert issued a statement Thursday saying Aldrin was visiting the South Pole with other tourists when "his condition deteriorated." The company said Aldrin was flown with a physician to the McMurdo research station on Ross Island in Antarctica and from there to New Zealand.

Aldrin was in stable condition, the statement said.

The National Science Foundation said it provided a humanitarian medical evacuation to McMurdo and then to Christchurch, New Zealand. Aldrin was taken to a local medical facility, the foundation said.

"After a grueling 24 hours we're safe in New Zealand," tweeted Aldrin's manager, Christina Korp. The tweet include a photo of Aldrin smiling in a hospital bed.

Before leaving for the South Pole, Aldrin tweeted Tuesday to almost 1 million followers: "South Pole here I come! #antarctica#WhiteDesert# GYATAntarctica "

Aldrin, an engineer and West Point graduate, joined NASA in 1963. He, Armstrong and Michael Collins made up the historic crew of Apollo 11 that rocketed from the Kennedy Space Center on July 16, 1969, bound for the moon. Five days later, Collins stayed aboard the command module while Armstrong and Aldrin took the module to the moon's surface.

The moonwalks were telecast live around the world to a mesmerized TV audience.

Armstrong's iconic first words: "That's one small step for man, one giant leap for mankind."

Aldrin's lesser-known words: "Beautiful view."

Aldrin, who was awarded the Congressional Gold Medal in 2011, remains "a tireless advocate for human space exploration," according to his own website. He's written nine books, including a children's book published last year Welcome to Mars: Making a Home on the Red Planet.

His 2013 book Mission to Mars: My Vision for Space Exploration lays out his vision for colonization of Mars. A key concept is his gravity-assisted Aldrin Cycler, which in theory would allow almost constant travel between Earth and Mars. A one-way trip would take less than six months.

Aldrin envisions the first trips in 2030, with missions lasting five years or longer. Initial exploration would be followed by colonizers, permanent settlements and eventually efforts to create a habitable Earth-like atmosphere.

The book also features some reflections on Apollo 11 — such as what he remembers as a virtual absence of public relations promotion ahead of the historic trip. Only after returning did anyone realize the value of the few snapshots taken on the moon, he writes.

After splashdown, Aldrin and Armstrong were quarantined. Together they watched a recording of TV coverage of their time on the moon.

"The whole world celebrated our moon landing," Aldrin said many years later. "But we missed the whole thing because we were out of town."