When George Takei remembers his friend and Star Trek co-star Leonard Nimoy, it's as a decent, thoughtful man.

Ahead of his upcoming visit to Australia to headline the Supanova Gold Coast Pop Culture Expo on April 17-19, the 79-year-old reflected on the time Nimoy went in to bat for him.

STAR TREK, James Doohan, DeForest Kelley, Walter Koenig, Majel Barrett, William Shatner, Nichelle Nichols, Leonard Nimoy, George Takei, 1966-1969 George Takei is coming to Gold Coast Supanova on April 17-19.

In 1973, the classic show was being turned into an animated series, but Takei (Mr Sulu) and co-star Nichelle Norris (Uhura) were not cast as voice actors.

"When Leonard discovered that, he said 'diversity is what Star Trek is all about, and the two people that represent diversity the most are Nichelle and George, and if they're not going to be with the project, then this project isn't for me'," Takei said.