Star Wars co-star Natalie Portman is storming back into action films with a role in the comic-book adaptation Thor. The 28-year-old Portman has been cast as Jane Foster, who was a nurse and first love of the title character in the Marvel Comics. According to Marvel Studios, the character is being updated for the movie version of Thor, in which the Norse warrior is cast down to Earth to live among humans. Chris Hemsworth stars as Thor in the movie, which begins shooting early next year. It is due in theaters May 20, 2011. Kenneth Branagh is directing Thor. The movie is part of an ambitious schedule for Marvel Studios, including Iron Man 2, The First Avenger: Captain America and The Avengers.