George Takei criticized William Shatner, a fellow Star Trek veteran, for embarking on a historic space voyage at the age of 90, reigniting a long-running feud that started on the set of the 1960s science fiction program.

George Takei and William Shatner have been exchanging insults for years, with Takei usually being the first. They reportedly did not get along when they were cast as Captain James T. Kirk and Hikaru Sulu in the 1960s Star Trek: The Original Series.

After Shatner’s short but significant “deep experience,” Takei described the 90-year-old as a “guinea pig” to see how space affects a “unfit” individual. Takei was speaking to Page Six.

“He’s boldly going where other people have gone before. He’s a guinea pig, 90 years old and it’s important to find out what happens.”

“So 90-years-old is going to show a great deal more on the wear and tear on the human body, so he’ll be a good specimen to study,” Takei noted, “Although he’s not the fittest specimen of 90-years-old, so he’ll be a specimen that’s unfit!”

The Canadian-born Shatner spent a brief period of time in weightlessness while in space, and after landing, he gave a protracted, rambling speech.

Shatner and newly minted astronauts Chris Boshuizen, Glen de Vries, and Audrey Powers experienced three minutes of weightlessness on Blue Origin’s New Shepard rocket earlier that day.

William Shatner got the last word in this case. The Captain Kirk actor conjectured that George Takei has a “psychosis” inside of him that forces him to go out of his way to disparage him, even on such a happy occasion as his historic space flight, in a statement in response to Page Six’s report about his remark. Shatner came to the conclusion that “pity” is his sole remaining emotion toward Takei at this point.

It’s important to note, though, that George Takei isn’t the only person to criticize William Shatner for his actions on the Star Trek set. There are numerous people the actor allegedly had problems with, including Nichelle Nichols, James Doohan, Walter Koenig, Deforest Kelly, and others. In fact, he mentioned in a 2016 interview with The Hollywood Reporter that Leonard Nimoy, who portrayed his character’s absolute best friend on the show, stopped communicating with him in his final years. Leonard Nimoy passed away in 2015 at age 83.

Takei once claimed that Shatner ignored him when filming “Star Trek V” and even changed the screenplay so that Takei’s character, Hikaru Sulu, wouldn’t be given command of a ship.

The two co-starred in six movie films, the last one being Star Trek VI: The Undiscovered Country in 1991, in addition to the renowned television program.

The “T.J. Hooker” actor has also been criticized by Takei for being “extremely self-centered.”

However, the former “I’m A Celebrity… Get Me Out Of Here!” contestant has insisted they don’t have a genuine feud and it is only played on when his former co-star is looking for “a little publicity.” Both George and William have previously acknowledged they exchanged harsh words while working on “Star Trek,” which debuted in 1966.

In a speech from 2015, George said: “No, there is no tension; Bill is the source of it all. He stokes the alleged conflict between us whenever he wants some press for a project.

“It’s difficult working with someone who is not a team player. The rest of the cast all understand what makes a scene work – it’s everybody contributing to it. But Bill is a wonderful actor, and he knows it, and he likes to have the camera on him all the time.”

Whether you support George Takei or William Shatner, the reality remains that Star Trek fans find it difficult to see such public insults directed at one star coming from another. While it would be lovely to live in a Star Trek-type universe where everyone stands together to fight shared foes like the Romulans or the Borg, it seems that the stars themselves still have some work to do before a real-world Enterprise bridge crew is feasible.

Celebrities including Joel Grey, Marilu Henner, and Nicole Ari Parker were present at the play’s opening night in addition to Takei. It is the first play on Broadway to have been written, directed, lead produced, and starring black performers.