Three more actors have joined Andrew Stanton’s big screen adaptation of Edgar Rice Burroughs‘ John Carter of Mars: Samantha Morton (In America, Control), Dominic West (300, Chicago) and Polly Walker (Patriot Games).

Morton, West and Walker join Taylor Kitsch (Wolverine, Friday Night Lights), Lynn Collins (X-Men Origins: Wolverine, True Blood), and Willem Dafoe in the Walt Disney Pictures production. Based on A Princess of Mars, which was first published in 1917, the movie will follow Civil War vet John Carter (Kitsch), who is transplanted to Mars, where he discovers a lush, wildly diverse planet whose main inhabitants are 12-foot tall green barbarians. Finding himself a prisoner of these creatures, he escapes, only to encounter Dejah Thoris (Collins), Princess of Helium, who is in desperate need of a savior and Tars Tarkas (Dafoe), a brutal and mirthless green Martian warrior, who possesses the unusual characteristic to feel love and empathy.

According to THR: “Morton will play Sola, the daughter of Tars Tarkas, who must hide her softer side from her warmongering race. West plays Sab Than, prince of the Zodangans who believes he is entitled to rule Mars. Walker plays Sarkoja, a merciless, tyrannical Thark.”

The film is expected to be the first of a possible trilogy. Stanton wrote the screenplay with Mark Andrews, and Michael Chabon also did a draft. Last we heard, John Carter is gearing up for a November shoot in Utah. Disney is aiming for a 2011 release. Stanton has been tweeting breifly about the preproduction location scouting on twitter.