It’s way too soon to know what went wrong with the space shuttle Columbia on Saturday morning, when it disintegrated upon reentry, killing all seven passengers. Within hours, NASA was promising that multiple commissions would investigate the disaster. Perhaps we’ll have answers someday. The debris that rained down on east Texas and Louisiana may provide some clues. Then again, there’s a good chance we’ll have to face the grim possibility of never knowing for sure what happened.
The causes of the 1986 Challenger catastrophe are now fairly well understood. NASA had advertised the space-shuttle program to Congress and the country as something akin to Amtrak service between New York and D.C., but it was launching shuttles far less frequently than it had promised and was feeling intense pressure to approach expectations. “A program that had been sold as providing what amounted to scheduled airline service was operating like a charter carrier in a banana republic,” writes William E. Burrows in This New Ocean.
So NASA ordered the Challenger spaceward when it shouldn’t have. There were three-foot-long icicles on the launch pad and the temperature on the ground was about 15 degrees colder than it had been on any previous liftoff. The rubber o-ring on one of the solid rocket boosters had hardened to the point where it shattered under pressure. Several people had warned NASA not to go forward because of the cold. The seven deaths were probably avoidable.
NASA grounded the shuttle fleet for nearly three years. The agency made various improvements to the engines, the external tanks, and the wings. It also created a low-altitude bailout option for the crew. (Most people don’t realize it, but the Challenger crew probably lived for about two minutes beyond the explosion whose image is seared into our minds, and they may have been conscious until the moment their cabin smacked into the sea at high speed.)
America’s first experience with space-program casualties occurred almost exactly 19 years earlier at Cape Canaveral, in 1967. Gus Grissom, Roger Chafee, and Edward White were strapped inside their command module for a test when the pure oxygen they were breathing burst into flames. They struggled to get out, but the hatch was not designed to blow open. All three men died. To this day, the cause of the fire remains unclear — even though their spacecraft never left the launch pad or went through the violence of an atmospheric reentry.
In the case of Columbia, there’s already speculation that a piece of orange insulating foam that is known to have fallen off a fuel tank during liftoff and believed to have hit the shuttle’s left wing may have contributed to the disaster. On Friday, NASA’s flight director said that this event did not pose a risk. By Saturday afternoon, people were second-guessing him, and perhaps there’s something to what they’re saying. There will certainly be an extensive debate over the shuttle program and whether to continue it. (Gregg Easterbrook makes a strong case to quit here.)
Yet we may soon have to confront the thorny problem of not knowing for sure what happened to Columbia — something that’s difficult to accept in an age of scientific rationalism and faith in technology. Several airline crashes, such as TWA Flight 800 in 1996, remain the subject of bitter controversy (to say nothing of conspiracy theorizing). Investigators looking into the Columbia failure simply may not have much to investigate, assuming that much of the material evidence they’d like to look at no longer exists. Exploration is often characterized as a voyage into “the unknown”; the forthcoming Columbia commissions may embark on a similar kind of journey.
If the cause of Columbia’s fate becomes an unsolved mystery, space experts will have to make an educated guess about how to move forward. We can be certain of one thing right now: The bravery of exploration has always required risking death. This was true in the day of Columbus, and it remains true in the day of Columbia. Isaac Asimov put it well after the Challenger was gone: “All of a sudden, space isn’t friendly. All of a sudden, it’s a place where people can die. … Many more people are going to die. But we can’t explore space if the requirement is that there be no casualties; we can’t do anything if the requirement is that there be no casualties.”