Sandra Bullock was left stunned when she left a phone message for an astronaut aboard the International Space Station - and received a call back.

Bosses at NASA allowed the actress to call Cady Coleman while she was researching her role in hit new sci-fi drama Gravity, but she didn't think she'd actually get the chance to chat to the spacewoman.

Bullock says, "It was incredible. I literally would dial a number and they were like, 'I'm going to call you back'.

"Cady Coleman was at the International Space Station at the time and she called me!"