What will it take to get Robert Downey Jr. in Cowboys and Aliens?

Writer/producers Alex Kurtzman and Robert Orci confirmed to SCI FI Wire that they have spoken with Iron Man Robert Downey Jr. about starring in their upcoming sci-fi western movie Cowboys and Aliens, but that getting him on board depends on his schedule.

"We've been talking to him about that," Orci said. "He's one of the busiest men on the face of the Earth. If the schedule can line up, we'd absolutely love it."

The writers—who have their fingerprints all over this year's Star Trek, Fringe and Transformers: Revenge of the Fallen—add that Cowboys and Aliens is closest to being the movie they complete next.

Cowboys and Aliens is based on the Platinum Comics graphic novel written by Fred Van Lente and Andrew Foley. Set in the mid-1800s in Arizona, it deals with an invasion by an extraterrestrial species with plans to enslave humanity, but cowboys and native Apache have other plans. Orci and Kurtzman are acting as producers and writers on the project for DreamWorks; Brian Grazer, Ron Howard and Steven Spielberg are also producing.

In an exclusive interview with SCI FI Wire, the creative pair spoke about the movie, which is eyeing a 2010 release. Following is an edited excerpt of our interview.

Cowboys and Aliens is based on Platinum Dune's fantastical graphic novel. How far are you along in developing the script?

Kurtzman: We are just about to finish our draft of Cowboys and Aliens, which we are writing with Lost's Damon Lindelof. 2012 we aren't doing anymore, because we were developing it, but then Roland Emmerich beat us to the punch.

Orci: For Cowboys and Aliens, we got an amazing first draft from Mark Fergus, who wrote Iron Man, and now we are continuing on with Damon. We are in the middle of the second draft.

What has been one of the challenges in bringing a comic-book property to the big screen?

Kurtzman: It's always that line of how much to keep from the graphic novel and what has to be altered to fulfill the tonal and production requirements of live action. There are certain things you can get away with in the graphic novel that doesn't translate to live action.

More from around the web