Astronaut Buzz Aldrin on plans to colonise Mars
Buzz Aldrin and Neil Armstrong were the first men to land on the moon in 1969, and since then there has been much talk of the next great space leap - putting a man on Mars.
Now the talk is serious and one of the men behind it is astronaut Buzz Aldrin himself, who said humans can not only land on Mars but also colonise the red planet.
Speaking on Radio 4's Today programme, "We'll lay out preparations up to that [going to Mars], in my mind we are doing it right now," he said.