Yesterday, the Columbia Accident
Investigation Report was released. In 248 pages, it covers both the accident and
the causes of the accident in detail, and presents a fascinating bit of forensic science.
The investigation that that board and NASA did into the accident is top-notch.
Unfortunately, it appears that NASA didn't learn from Challenger, as there are eerie
parallels between the two accidents. Both are issues that had been observed for years,
and were gradually downgraded from "critical safety issue" to "known risk", apparently
on the theory that there hadn't been any serious problems yet, and therefore there
wouldn't be any in the future.
Like the o-rings in the SRBs, there has been a long history of continual damage
to the orbiter due to shedding of the foam. Page 127 has a very telling report - none
of the flights were free of damage from the foam (the chart covers lower-surface dings
> 1" in diameter). In most flights, there were 10-20 areas damaged, and in 4 flights,
there were over 100. Before Columbia, there were 5 known cases of the foam coming
off in the same place as in Columbia (there are likely more, since less than
half the flights had enough imagery to be sure).
Even if NASA didn't see this as a safety issue, repairing the damage after every mission
(and there is lots more damage at smaller sizes) takes a considerable amount of time
and expense. For a organization who wanted to reduce operating costs, not solving
that problem was a big issue.
Overall, it's still a case of NASA trying to do too much with too little, and not
being frank about what they could really get done. I don't think NASA as an organization
is going to achieve low-cost access to orbit. My money is on guys like Burt