YouTube's lunarmodule5, a treasure trove of jaw-dropping space videos, takes us onboard Apollo 13 to relive the harrowing hour when the doomed moon mission turned into a quest for survival. No Hollywood movie could ever muster the real-life drama and tension of this moment.

You've got to put on headphones to fully appreciate this. In your right ear, you'll hear the radio link between Apollo 13's crew and Houston; in your left, the communications of the flight control team on the ground. At 3:37, you'll hear Command Module Pilot Jack Swigert's now-famous transmission, "Houston, we've had a problem."

Then there are the visuals. Video footage from the Data Acquisition Camera inside the spaceship is stunning in its stark depiction. Scenes from the Mission Operations Control Room on the ground are harrowing. And the TV newsreels show how this near-catastrophe played out in real-time for millions of Americans anxious for updates.

This had to have been the most high-tension moment in any of these people's lives. Yet what you see and hear isn't panic. It's the measured, precise responses of highly-trained experts, scrambling to save the lives of three men stranded 173,000 miles from earth in a crippled ship. Flight Director Gene Kranz later referred to these moments, and the successful return of the crew, as "NASA's finest hour." Watching it all unfold, it's impossible to disagree. [lunarmodule5]