William Shatner thinks the Duke of Cambridge has the "wrong idea" following his criticism of space tourism.
Prince William said this week that entrepreneurs should be focusing on saving the planet we're living on instead of investing billions into finding "the next place to go and live", with the likes of Jeff Bezos and Elon Musk both chartering leisure trips into space in recent months.
He said: "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.
"It really is quite crucial to be focusing on this [planet] rather than giving up and heading out into space to try and think of solutions for the future."
And now, 'Star Trek' actor Shatner - who became the oldest person ever to travel into space this week when he took a trip with Jeff Bezos' Blue Origin as one of four passengers on board the New Shepard NS-18 ship - has said he disagrees with the royal's comments.
Shatner, 90, insisted: "He's a lovely Englishman. He's going to be king of England one day. He's a lovely, gentle, educated man, but he's got the wrong idea."
The actor said his own journey into space wasn't about showing off, as he claimed he's keen to see a solution in the future which takes all "polluting industries" into space, so they don't contaminate the earth.
He added: "The idea here is not to go, 'Yeah, look at me. I'm in space.' The landing that consumed all that ... energy and people to take a look and go, 'Oh, look at that.' No.
"I would tell the prince, and I hope the prince gets the message, this is a baby step into the idea of getting industry up there, so that all those polluting industries, especially, for example, the industries that make electricity ... off of Earth."
Shatner also believes Prince William is "missing the point" of current space travel missions.
He said: "The prince is missing the point. The point is these are the baby steps to show people [that] it's very practical. You can send somebody like me up into space."
However, the actor does agree with the royal about their being issues that need to be addressed on Earth before we jet off to a distant planet.
Speaking to 'Entertainment Tonight', Shatner said: "So fix some of the stuff down here … But we can curl your hair and put lotion on your face at the same time."