Heiko has found an excellent FAQ on the loss of the shuttle Columbia which answers pretty much every question I have been asking these last few days.

• Just how toxic is the debris: “Contrary to some crackpots, trolls and wannabee eBay scammers, handling the Columbia debris could very well be as suicidal as bailing out at 200,000ft in the middle of a 3000F plasma stream…” some of the propellants on the debris can spontaneously ignite, while others will induce irritable eyes, skin and respiratory system and cause comiting, diarrhea (sic) and permanent damage to internal organs considered “immediately dangerous to life” at a concentration of 50 parts per million.

• The astronauts could not have gone under the shuttle to take a look at any potential damage because they simply didn’t have the equipment available to get around there, and even if they did the crew probably wouldn’t be able to do any tile repairs so it would have been pretty pointless. Also, the crew didn’t have space suits that were rated for “spacewalk duty” - ie only really suitable for wearing inside.
• They could not dock with the space station to do the repairs because the orbit Columbia was slated for didn’t take it anywhere near the station. So, naturally, they didn’t bother installing the means of connecting the shuttle and station to one another.
• There is over 100 miles of wiring inside a shuttle.

1. Columbia
   NOTE TO PERSONS IN THE AREA: All debris is United States Government property and is critical to the investigation of the shuttle accident. Any and...
   
   
2. Columbia for sale
   Fortunately, eBay has removed these items from its auctions. I'm guessing Nasa would be keen to talk to the owners. ...
   
   
3. Weightless debris
   'Could Ejection Seats Have Saved the Columbia Astronauts?' asks a feature in Slate. The answer, on grounds of height and speed, is a fairly definitive...