The Duke of Cambridge has said he has “absolutely no interest” in becoming a space tourist, saying he once travelled to 65,000 feet in a plane and that was high enough.
William has criticised the space race, saying the world’s greatest minds need to focus on trying to fix their own planet instead.
The duke described his past experience as “truly terrifying” and said he did not achieve weightlessness but the sky was black above him and he saw the curve of the earth.
His comments, in an interview with BBC Newscast on BBC Sounds, were aired the day after Star Trek’s William Shatner made history by becoming the oldest person in space.
The 90-year-old actor, known for his role as Captain James T Kirk, lifted off from the Texas desert on Wednesday in a rocket built by Amazon founder Jeff Bezos’s space travel company Blue Origin.
The duke said what the carbon footprint of short journeys into space would be is a “fundamental question”.
He said: “I think for me particularly the idea of this space race that’s on at moment – we’ve seen everyone trying to get space tourism going – it’s the idea that we need some of the world’s greatest brains and minds fixed on trying to repair this planet, not trying to find the next place to go and live.
“And I think that ultimately is what sold it for me is that, that really is quite crucial.
“We need to be focusing on this one rather than giving up and heading out into space to try and think of solutions for the future.”
Asked by presenter Adam Fleming whether he would like to become a space tourist one day, the duke replied: “Do you know what, I have absolutely no interest in going that high.
“I’m a pilot, but I’m a helicopter pilot so I stay reasonably close to the ground.
“I’ve been up to 65,000 feet once in plane, that was truly terrifying. That’s high enough.”
William said it was not quite high enough to achieve weightlessness, adding: “The sky is black above you and you can see the curve of the earth. That’s close enough to space for me because you can come back down again. It’s in the orbit so it’s okay.”
As Fleming expressed concern about what the carbon footprint of a rocket going into space for a 10-minute trip would be, William replied: “That is also a fundamental question.”
The duke, who spoke about climate change ahead of his inaugural Earthshot Prize awards, also discussed his children Prince George, Princess Charlotte and Prince Louis, saying he felt bad about giving them the “burden of that worry” about how the resources they use impact the planet.
William said George is aware of the importance of actions such as turning off lights and not overusing water.
The duke said: “He is acutely aware, more so than the other two at the moment.
“Charlotte is still a little bit young. She’s still not quite sure. And actually Louis just enjoys playing outside the whole time. He lives outside.
“But I think it is slowly dawning on them that these things matter.
“But I think when you’re that young, you just want to have fun and enjoy it.
“I feel bad, I don’t want to give them the burden of that worry.”
George has been expressing his frustration at the relentless battle against discarded waste after litter-picking expeditions at school, William added.
The eight-year-old was confused and annoyed when his class returned to the same route the next day to find it was full of litter again.
“I think that, for him, he was trying to understand how and where it all came from,” the duke said.
“He couldn’t understand, he’s like, ‘Well, we cleaned this. Why has it not gone away?’”
The duke also warned the Cop26 climate change summit, where world leaders will gather in Glasgow at the end of the month, against “clever speak, clever words but not enough action”.
He said: “I think for Cop to communicate very clearly and very honestly what the problems are and what the solutions are going to be, is critical.
“We can’t have more clever speak, clever words but not enough action.”
William discussed his ambitious Earthshot Prize, saying it was about trying to create action.
The £50 million initiative aims to find solutions to the planet’s problems throughout the next decade.
The winners in the five categories this year will each receive £1 million to develop their projects after being chosen by a judging panel.
William and the Duchess of Cambridge are attending the star-studded ceremony, hosted by Clara Amfo and Dermot O’Leary, at Alexandra Palace in London on Sunday.
BBC Newscast: The Prince William Interview is available on BBC Sounds and BBC 5 Live.
It also airs on Thursday on BBC One at 11.35pm, and on the BBC News Channel and BBC iPlayer.