Like many of you, I'm eagerly anticipating Alfonso Cuarón's upcoming space drama "Gravity." Starring Sandra Bullock and George Clooney, it promises to be an eye-popping piece of 3D grandeur from an auteur who has already given us some of the most indelible cinematic imagery of his generation.

Everyone's waiting for the first trailer for the film, which should hit sometime soon. But while we wait, let me pass this bit of info along. A source who's seen "Gravity" (and is over the moon about it) tells me that Ed Harris is featured in the role of a mission control voice. It might seem like just a cool bit of casting with a recognizable voice, but it's also a nice ode to one of the actor's Oscar-nominated performances.

In 1995, Harris landed his first Academy Award nomination for Ron Howard's "Apollo 13." In the film, he starred as NASA Flight Director Gene Kranz, who played a key role in bringing the doomed Apollo 13 crew back home safely. He won the Screen Actors Guild Award for his work in the film, but Kevin Spacey bested him at the Oscars with his career-making turn in Bryan Singer's "The Usual Suspects."

Harris is one of only five actors credited on the studio's official credit listing for the film, and indeed, will be but a small part of the movie. The film is largely dominated by Sandra Bullock, who my source says is fantastic (watch for a serious Best Actress push in the fall). The story is episodic, I'm told, with Bullock's character overcoming a new obstacle (after being stranded in space following a space shuttle disaster) and then moving on to the next one. But while it plays on thrilling elements, it ultimately becomes a fairly moving piece.

The real star of the film, the source confides, is the filmmaking itself. The opening 16-minute single take has been written about, but there are apparently a number of these throughout the film, recalling some of the more riveting moments from Cuarón's 2006 film "Children of Men." Some of these takes even become POV shots and it's all very smoothly handled. I'm also told Steven Price's score is very good (Cliff Martinez's work was noted by way of comparison) and the various elements -- visual effects, sound, 3D photography -- amount to an incredible experience.

But the news here is that Harris has joined the cast in a role that will have fans of the actor smiling when a familiar voice flashes on the soundtrack.

Listen for it when "Gravity" hits theaters on October 4.

UPDATE: And here's the trailer...