Day of Remembrance

I have to say I feel a little bit ashamed. But, that's where the internet can help. Today is the 18th anniversary of the explosion of the Space Shuttle Challenger. It is also on this day that NASA pays homage to the crews of Apollo 1 and the Space Shuttle Columbia. There are some very moving tributes on http://www.nasa.gov.
I would also recommend reading about all the astronauts. Particularly in the case of the Challenger explosion, we remember Christa McAuliffe, but forget the other 6.