Former astronaut Buzz Aldrin has been cleared to go home after spending more than a week in Christchurch hospital.
The second man on the moon became the oldest person to reach the South Pole at 86, before he had to be medically evacuated due to fluid in his lungs.
He was flown from McMurdo Station in Antarctica to Christchurch, where he rested up before returning to the US.
Mr Aldrin's manager, Christina Korp, tweeted a photo of him on the flight home, saying they hoped to return again.
"But next time for vacation and not evacuation," she wrote.
Mr Aldrin began showing signs of altitude sickness, including low oxygen levels and congestion in his lungs, after reaching the South Pole.
"Once I was at sea level I began to feel much better," he said last Sunday.
NASA is currently studying Antarcticans to see how people can cope in extreme weather and isolation, which people would face on a trip to Mars.
Part of Mr Aldrin's trip was planned around the same idea, and he said he didn't get to talk to the scientists as much as he would've liked about their Mars work.
"My visit was cut short and I had to leave after a couple of hours," he said. "I really enjoyed my short time in Antarctica and seeing what life could be like on Mars."