Mitchell: Houston, we have a problem.
This phrase has become a cliché for understating the severity of a bad situation, having its origins in the Apollo 13 moon mission. This was supposedly the message sent from the command module (also named Odyssey) to inform Capcom that the main oxygen tank had exploded. However, this was not the actual quote. Command module pilot Jack Swigert first said, "Okay, Houston, we've had a problem here." Mission Commander James Lovell later said, "Houston, we've had a problem."