Misc. Ramblings

Today marks the 35th anniversary of the near fatal explosion on NASA's Apollo 13 mission to the moon. At the same time it was NASA's worst and finest moments. The story behind the story is that Apollo 13 made it home, due in large part, to a simulation done a year before the explosion for Apollo 10.

As part of training, the flight teams go through various scenarios. Each scenario is carefully scripted and is intended to prepare everyone for possible problems. The fear is that if you come across something you haven't prepared for, you may perish because you don't have the time or you do something that irreversibly leads to your death.

Such was the case in a simulation for Apollo 10 much like what eventually happened. A flight simulation in which the fuel cells failed, at about the same point in the mission as actually occurred, resulted in the simulated deaths of the astronauts because they didn't have procedures required to power the various systems (and didn't have the time to come up with them in real time before running out of oxygen).

However, even though the simulation indicated developing such procedures were critical to the crews survival, NASA decided the possibility of losing the fuel cells was unrealistic and therefore did not order such procedures to be developed.

Fortunately, for the Apollo 13 crew, James Hannigan, the Lunar Module branch chief felt otherwise. He ordered his deputy, Donald Puddy, to form a team to come up with a set of procedures that would work. Just in case. Critical to the procedure, that the team came up with was the idea of reversing the power flow, via umbilical cables, from the Lunar Module back into the Command Module to provide the current required to re-start all the systems.

It is doubtful that the crew would have survived the actual emergency had not these procedures been developed before hand and solutions found for problems that just could not be solved in real time.

You can read the fascinating account of human systems dealing with mechanical and electrical systems from the Institute of Electrical and Electronics Engineers article, here. It was indeed, their finest hour.