George Clooney learned to rappel out of a helicopter for this part. He found it "fun and weird and scary."
George Clooney was so starstruck by Armin Mueller-Stahl that he kept offering to get him coffee on set.
The part removed from the bomb is called the "primary". This means that these bombs are thermonuclear bombs. The primary is a small nuclear bomb which is used to start the chain reaction in a much more powerful second bomb.