Columbia has joined Challenger and Apollo 1 as spacecraft of the past that have met a tragic end. Another brave crew of astronauts has been lost. Now comes investigations, and discoveries about what went wrong and why, and delays, and likely abandonment of the International Space Station at least for a while. These are details; crucial, critical details to be sure, but in the long run not the most important issue at hand. The most important thing is after the investigations and delays, what comes next. The human expansion into space is a process that will take centuries, even millenia…or it may not even happen at all. The loss of Columbia is a crossroads of history. After Apollo 1, America continued on to the moon. After Challenger, America climed back into the Space Shuttle and headed once more into the skies. We can and must show the same spirit and determination now. The future depends on it.

In the present, though, it is time to mourn.