Actress Sandra Bullock fought to play the mother of a dead child in Gravity even though she knew the role would be tough because she's a happy mum in real life. The Speed star portrays a desperate doctor lost in space in the hit sci-fi movie and when director Alfonso Cuaron was creating the character she urged him to consider giving her a sad life on earth back story. Bullock tells Entertainment Weekly she knew it was important to give her character no one to come back to. She explains, "I said I didn't want her going back to a child, because of course someone's going to fight for that. So what if she had absolutely nothing to fight for - she's lost a child, there's nothing back home, she's a person who's basically a machine? "That was my idea, and Alfonso was open to it. It was the worst possible headspace to be in... but at the end of the day, I went out into the sunshine, out to where the life force was - my son."