“It’s really in the early stages at this point,” Chris Doohan said. “He’s doing fine.”

Doohan said his father is relaxing in retirement in Washington state with his wife, Wende, and the daughter he beamed up when he was 80. Chris Doohan said his father, at this time, has been more slowed by Parkinson’s disease and diabetes than Alzheimer’s, the incurable, progressive neurological disorder that affected Ronald Reagan.

“If you ask him about D-Day, he’ll go on about an hour about D-Day,” Chris Doohan said.

A native of Canada, James Doohan fought, and was wounded, in that historic World War II battle as a captain in the Royal Canadian Artillery.

To the world, Doohan is best known as Montgomery “Scotty” Scott, the fiery chief engineer of the U.S.S. Enterprise.

Doohan milked the maximum out of his ship’s dilithium crystals on the original Trek series from 1966-69. He reprised the role in the first seven theatrical Trek films, including a cameo in 1994’s franchise crossover, Star Trek: Generations.

In August, he’ll bid farewell to the still thriving Trek convention circuit, with “Beam Me Up Scotty…One Last Time,” a three-day fest that’s billed as his last-ever con appearance.

“He wants to say thank you to [the fans],” Chris Doohan said.

All surviving crew members of original-formula Trek are scheduled to put in appearances at the Aug. 28-30 event in Hollywood: Leonard Nimoy, Nichelle Nichols, George Takei, Walter Koenig, Majel Barrett, Grace Lee Whitney, even William Shatner, with whom Doohan famously clashed with for years.

“It’s all water under the bridge at this point,” Chris Doohan said. “My dad and William Shatner got together recently and told each other how much they love each other.”