Wearing my absolute favorite watch of all time today.
It was the Omega Speed master watch, the first watch worn on the moon and today still the only watch certified by NASA for EVA, that helped save the lives of the Apollo 13 astronauts.
"Another burn was needed, but no help from the guidance system would be available, as powering the lander’s guidance system, its gyros, the computer, etc. would use too much electrical power.
Here’s where the backup navigation approach that Lovell experimented with on Apollo 8 came to the rescue.
“If a ‘dead-reckoning’ approach could be used, no electricity would be needed,” said Woodfill. “Simply point the vehicle correctly, start the engine and stop it based on Mission Control’s prescribed time for its operation.” Lovell eyed up the Earth’s terminator line and controlled the “yaw” of the spacecraft, Haise controlled the “pitch” and Swigert timed it with his accurate Omega Speedmaster watch.”
Read more: http://www.universetoday.com/62763/13-things-that-saved-apollo-13-part-6-navigating-by-earths-terminator/#ixzz31RP5PqAM