Tragedy strikes the U.S. space program again, for the first time since 1986. The Columbia orbiter was the first in NASA’s fleet, delivered in 1979 and first launched in 1981; it has gone through a retrofit and two complete overhauls since, though, and was most recently returned to service in early 2002. It also was the only orbiter originally not involved in the building of the International Space Station, since its weight made it impractical for carrying the necessary heavy equipment and modules into orbit. It came out of its last overhaul lighter and capable of reaching the ISS, however, and was scheduled to start helping with construction in November. (Interestingly, one crew member of that November launch was supposed to be Barbara Morgan, who was Christa McAuliffe’s backup on the fated Challenger mission.)

Last time the U.S. lost an orbiter, launches were postponed for nearly two years while the investigation was completed and modifications were made. This time, there are two big differences, and unfortunately, it seems to me that they conflict with each other. First, there doesn’t appear to be any video (or other precise witness information) about the Shuttle failure; after the Challenger disaster, the video appears to have played an almost critical role in the investigation, and I wonder what its absence will mean to the length of time it will take to determine what happened this morning. Second, and more importantly, we have astronauts up on the space station right now, and they’re supposed to be retrieved and replaced next month. I wonder if we’ll rely on Russia’s Soyuz transporter in the interim (since, as far as I know, it’s the only option available to us for manned spaceflight to and from the ISS). (Funny — while I was writing this, Time published a question-and-answer piece that ended with the same conclusion.)

What a terrible disaster.