Actress Natalie Portman was offered the chance to replace Angelina Jolie and star alongside Robert Downey, Jr. in an upcoming 3D sci-fi movie called “Gravity.” Jolie recently pulled out of the movie and producers are reportedly courting Portman (after previously considering fellow actresses Blake Lively and Scarlett Johansson) for the film’s lead role.

If Portman decides to take on the starring role in “Gravity,” she will play a woman stranded on a space station after a crash killed the rest of her crew. Robert Downey, Jr. has already committed to the supporting role for the film, which is scheduled to begin shooting at the top of 2011 before Downey has to film other projects.