Had the Columbia astronauts looked at a hole in the wing and sought to fix it themselves, they would have had a fair chance of making the problem worse, according to the report.

And in spite of the changes to the crew cabin made after Challenger, the Columbia astronauts were still not safe.

Atlantis was designed for seven crew members but would have launched with four, so that the Columbia astronauts could squeeze in, some sitting on the floor.

The Columbia astronauts would have donned the jet packs, and moved into the Atlantis, following a tether (see illustration above).

Some Columbia astronauts had no extravehicular training at all; normal training time is nearly a year.

Some people who had little or no contact with the Columbia astronauts have found the going easier.

The families of the Columbia astronauts could sue Boeing and Lockheed Martin, whose joint venture, United Space Alliance, manages shuttle launchings.

But even if Columbia astronauts had spotted the problem, it is not clear whether they could have done anything, beyond tweaking their re-entry path and hoping for the best, to save themselves.

A group of women who had been part of the Houston training crew of the Columbia astronauts sobbed.

I hope that the unfortunate death of the Columbia astronauts will forever sever the false link that has been created between the two.