"Of course you have to clean up the plastic in the ocean — it doesn't mean you can't work on getting industry off of the ground," the Star Trek icon tells PEOPLE

William Shatner, Prince William
Credit: Santiago Felipe/Getty; Max Mumby/Indigo/Getty

Prince William and William Shatner do not see eye to eye on the space race.

After his return to Earth on Wednesday, the 90-year-old actor is opening up to PEOPLE about his "indescribable" journey aboard a Blue Origin New Shepard capsule, which made him the oldest person to ever go to space.

Prince William, however, believes such space tourism trips shouldn't be a priority.

"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," William, 39, told the BBC on Thursday, without mentioning Shatner by name.

"I think that ultimately is what sold it for me — that 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," William added during the interview, which was held before the British royal's first Earthshot Prize awards ceremony on Sunday.

"That's inane," Shatner says of William's perspective.

The Star Trek actor points to potential technologies that could be developed in space to provide humans with energy on Earth — without polluting the planet and worsening the climate crisis.

"This is what Bezos wants to do," he says of billionaire Jeff Bezos' goal to use his aerospace company to build "a road to space with our reusable launch vehicles, so our children can build the future."

William Shatner's trip to space aboard Blue Origin's Rocket
Blue Origin launch
| Credit: CNET Highlights

"Why wouldn't [Prince William] want to do that?" says Shatner. "I would put that in front of anything."

"I'm surprised at him making that statement," the Emmy winner continues. "You can do two things at once. Of course you have to clean up the plastic in the ocean — it doesn't mean you can't work on getting industry off of the ground."

On Wednesday, Shatner was moved to tears by the 11-minute suborbital trip, which took him and three other crew members past the Kármán line, the internationally recognized border of space.

Watch William Shatner’s Hilarious Reaction to Floating in Space: ‘Oh Jesus’
William Shatner
| Credit: Blue Origin/Twitter

"In a way, it's indescribable," Shatner told Bezos while taking his first steps after landing.

"Everybody in the world needs to do this," Shatner added. "Everybody in the world needs to see."

Shatner put into words how seeing Earth from space changed him — a phenomenon some astronauts call the "Overview Effect."

RELATED VIDEO: William Shatner Flies to Space, Making History as the Oldest Person to Leave Earth

"I hope I never recover from this. I hope I can maintain what I feel now. I don't want to lose it. It's so, so much larger than me," he said. "It has to do with the enormity and the quickness and the rudeness of life and death."

"What I would love to do is communicate as much as possible the jeopardy, the moment you see the vulnerability of everything," he added. "It's so small. This air which is keeping us alive is thinner than your skin. It's a sliver. It's immeasurably small when you think in terms of the universe. I am overwhelmed. I had no idea."