On this day 56 years ago, three men fell from the sky in a freezing, half-dead spacecraft and landed in the Pacific Ocean. They had been given almost no chance of coming home alive.Six days earlier, astronauts Jim Lovell, Jack Swigert, and Fred Haise launched on Apollo 13, heading for the Moon. Two days into the flight, 200,000 miles from Earth, an oxygen tank exploded and tore a hole in the side of their ship. Within minutes, they were losing oxygen, losing power, and losing heat.There was no p