Phil Plait (AKA The Bad Astronomer) recently made a post about the 40th anniversary of the Apollo 1 fire that killed three of mankind's finest. He explains in exquisitely simple detail (yes, simple detail) how exactly the fire happened and what lead to it. Then he talks a little more and that's when (in case you aren't a space nut) you should sit up and pay attention.
It is an incredibly inspirational post. You should read it now if you care at all about astronomy, space, exploration, science, the human spirit or junk like that. Seriously.