Impossible but true: Tom Cruise, upside down half a mile in the air

Tom Cruise dangles out of a window of the Burj Khalifa while Jeremy Renner attempts what looks like a rescue as filming continues for 'Mission Impossible -- Ghost Protocol' on Wednesday, November 3 (PATRICK CASTILLO)
And it gets better: US actor Tom Cruise and his crew are hanging by ropes from the top of the world’s tallest building, the Burj Khalifa, while filming a stunt for Mission: Impossible Ghost Protocol in Dubai (PATRICK CASTILLO)
High-rise stunts in Dubai as actor Tom Cruise and his crew hang on harnesses from the top of the world’s tallest building, the Burj Khalifa, on Wednesday, November 3 (PATRICK CASTILLO)
The actor took 75 of his Mission Impossible crew and castmates, including British actor Simon Pegg and Jeremy Renner, out go-karting at the Dubai Kartdrome. (PATRICK CASTILLO)
Zooming in for the details: Crew set up a shot as Tom Cruise dangles upside down from the the world’s tallest building, the Burj Khalifa, on Wednesday, November 3 (PATRICK CASTILLO)
Is that really Tom Cruise dangling off the side of the Burj Khalifa? Or is it a dummy? Will we ever know? Crew film a stunt for 'Mission: Impossible Ghost Protocol' in Dubai on Wednesday, November 3 (PATRICK CASTILLO)
US actor Tom Cruise and his crew are hanging by ropes from the top of the world’s tallest building, the Burj Khalifa, while filming a stunt for Mission: Impossible Ghost Protocol in Dubai, November 3, 2010. (PATRICK CASTILLO)
We didn't know those windows open up: US actor-producer Tom Cruise and his team crew on harnesses hanging from the top of the world’s tallest building, the Burj Khalifa, while filming a stunt for Mission: Impossible Ghost Protocol in Dubai on November 3 (PATRICK CASTILLO)
Hollywood actors Tom Cruise (C), Paula Patton and Jeremy Renner poses during a news conference ahead of beginning filming for 'Mission Impossible Ghost Control' in Dubai on Thursday, October 28. (PATRICK CASTILLO)
Hollywood actor Tom Cruise reveals the name of the fourth 'Mission:Impossible' film at a news conference in Dubai on Thursday, October 28 (PATRICK CASTILLO)
The cast and crew of 'Mission Impossible -- Ghost Protocol' at a news conference in Dubai on Thursday, October 28 (PATRICK CASTILLO)