Joss Whedon, back in the director's chair to helm a new episode of Firefly, has been comparing the ensemble cast with that of his other shows.

"Every set has its own sort of tenor," he told Sci Fi Wire. "The thing about Firefly is [that this whole cast is] extremely kind and professional. They get along, they help each other, and they work hard.

"I'm not saying my other casts don't work hard. And some of them get along, and it's great. But there's a star, and then there's the ensemble. And there's tensions on the set. It's not one big happy family. It seldom is on a television set."

The Firefly episode, Objects in Space, will be episode 11 in the new show's run. The Fox network have recently commissioned two more episodes. That, along with improved ratings and a more favourable response from US TV critics, bodes well for a full season of the show.