Challenger

Today marks another sad anniversary for NASA and the nation. On this date in 1986, 73 seconds after launch on an unusually cold Florida morning, space shuttle Challenger and its launch stack exploded, killing all seven of its crew. They were the first people lost during an American spaceflight, and the only such losses in the twentieth century-- a remarkable record for such a hazardous undertaking.

As always, Challenger's launch was open to the public, and because the first teacher-astronaut, Christa McAuliffe, was part of the crew, children across the country watched the tragedy as it happened. A NASA investigation eventually determined the chilly temperatures played a role in the explosion, but put most of the blame on a NASA culture that had allowed a relaxation of standards, including safety procedures.

Barbara Morgan, McAuliffe's backup that day, stayed with the program and finally got her flight last year. NASA recovered from Challenger, and is now winding down the shuttle program after what will be thirty years, during which-- so far-- only two flights have been lost. Another such tragedy would almost certainly end the program. The shuttle's record presents a mixed picture, one marred by Challenger and Columbia. Perhaps the final judgment will be that the shuttle was a good concept that, for various reasons, never reached its promised potential.