Nineteen years and six months ago today I was sitting in junior high reading class when I heard the terrible news. 75 seconds into the flight of STS-51L the space shuttle Challenger had exploded. It was a terribly sad day. Ultimately one can look at the accident that January morning in several ways. In an appendix to the Rogers Commission report on the events that morning Richard Feynman observes that "the slow shift toward decreasing safety factor can be seen in many examples."

The well-documented decline in safety standards is nowhere more evident than the terrible tragedy of the loss of the Columbia in February 2003. The theme Feunman documented after the Columbia incident seems to be at work still. It is a critical flaw in thinking that because a failure wasn't so bad last time it won't be bad next time.

Now, with the Discovery on its way to the International Space Station comes word that NASA has suspended future shuttle flights. The problem? The same problem that caused the Columbia disaster. This following several days delay related to troubleshooting a faulty sensor. All of this calls into serious question whether the culture of decreasing safety standards has really been addressed.