Alfonso Cuarón’s script for the 3-D space drama Gravity allegedly has the most coveted female role in town, yet he can’t seem to find an A-lister willing to take it. After Angelina Jolie passed twice on the picture (where she’d star as a determined astronaut opposite Robert Downey Jr.), Cuarón offered the lead role to Natalie Portman based on the strength of her Black Swan buzz. However, Deadline is reporting that Portman has now passed (perhaps she wasn’t eager to take on a demanding role this January at a time when she’d presumably be in the thick of her Oscar campaign?). In the meantime, Warner Bros. is prodding Cuarón to consider the suddenly very picky Sandra Bullock, because they apparently want the poor bastard to get his heart broken again. [Deadline]