Some of us lived through it, others watched The Right Stuff. Either way, we know all about the Apollo 1 mission and how it ended. 50 years after the fire that occurred during a rehearsal launch—killing Gus Grissom, Edward H. White, and Roger B. Chaffee—NASA is honoring the tragedy for its historical significance by displaying the capsule at the Kennedy Space Center in Florida.
The event that occurred on January 27, 1967 was intended to be a "plugs out" test to ensure that the spacecraft would function on internal power while detached from its cables. If all had gone according to plan, the shuttle would've launched on February 21st of that year.
Upon entering the capsule that day and strapping into their seats, Grissom immediately noticed something wasn't right. He sensed an odor circulating through the vessel which he compared to "sour buttermilk." It was later deemed that this scent had no effect on the fire, but in any event, the countdown was put on hold for several minutes.
One hour and forty-two minutes after the initial countdown was supposed to begin, the countdown resumed. Three minutes later, the hatch installation was started. As soon as the hatches were sealed, air in the cabin was replaced with pure oxygen to simulate what would occur when the capsule left Earth's atmosphere.
Things seemed completely normal until there was a momentary increase in AC Bus 2 voltage. Not long after, shouts of "Fire!... Open 'er up" were shouted through the communications system. The fire quickly became an uncontrollable inferno as the pure oxygen level rose way too high. Then the Command Module's inner wall ruptured, causing a sudden blast of air to further engulf the entire cabin.
Fallout from the disaster was ubiquitous across political agencies, committees, and NASA itself. The Apollo program was grounded and forced to perform a review and redesign of the Command Module. The original Block I spacecraft would only be used for unmanned Saturn V test flights. Manned missions would use the Block II spacecraft which contained several major design changes—cabin atmosphere adjustments, nylon flight suits replaced with non-flammable beta cloth, and use of a cartridge of pressurized nitrogen to stimulate the release mechanism during an emergency.
The anniversary also sheds light on the fact that it's been a very long time since the NASA space program was relevant. Luckily, in June of last year NASA announced plans to build a series of new X-planes over the coming decade. Hopefully this will reinvigorate the next generation's interest in life beyond our atmosphere.