George Takei Brands William Shatner 'Unfit' Guinea Pig After Historic Spaceflight

George Takei took a jab at his former "Star Trek" co-star William Shatner for taking a historic trip to space at the age of 90, reigniting their decades-long feud.

The 84-year-old actor threw major shade when he commented on Shatner becoming the oldest person to travel to space during Wednesday's roundtrip with Jeff Bezos' Blue Origin to the edge of space.

"He's boldly going where other people have gone before," Takei told Page Six at the opening of "Thoughts of a Colored Man" Wednesday night. "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. Although he's not the fittest specimen of 90 years old, so he'll be a specimen that's unfit!" he added.

Shatner successfully completed the voyage aboard the Shepard rocket for the NS-18 mission Wednesday. The Canadian-born actor experienced a few minutes of weightlessness aboard the spacecraft, where he was joined by three other passengers.

Upon his arrival back to Earth, Shatner shared an emotional testimonial about "the most profound experience" he's ever had.

"I’m so filled with emotion about what just happened. I just, it’s extraordinary, extraordinary. I hope I never recover from this. I hope I can maintain what I feel now," he was quoted by The Verge as saying.

Over the decades, Shatner and Takei have kept up a purported feud that began on the set of their show "Star Trek," which first premiered in 1966.

Takei accused the Captain James T. Kirk actor of ignoring him on set and changing the script for"Star Trek V" so his character, Hikaru Sulu, would not receive command of a spaceship. He has also slammed Shatner as "very self-centered."

Shatner dismissed Takei's accusations, claiming that "there's a psychosis there." He also claimed that Takei was unhappy about something and was taking it out on him, adding, "It’s sad, I feel nothing but pity for him."

However, Takei previously claimed that there's no real feud between them, telling The New York Times Magazine in 2015 that Shatner only brings up their "controversy" when he "needs a little publicity for a project."