[MrNatural]

The shuttle's airframe was originally certified for 100 flights; however, the
shuttles were intended to fly much more often. The Columbia was therefore like
an automobile that had only been driven 20K miles but was 30 years old. Their
equipment and 'running gear', if you will, is refurbished and upgraded periodically,
but the airframe itself is Original Equipment.

There's a reason why car makers say five years or 50,000 miles,

[CFC__VRWC]

The shuttle's airframe was originally certified for 100 flights;

Thanks for this post - I was wondering about this. As I recall, we now have three shuttles in service - Atlantis, Discovery and Endeavour. Are there any other shuttles in the pipeline? It seems that NASA will almost have to commission at least one new one if there isn't already one under construction.

[Steel Wolf]

Quesiton from another thread: How much wind resistance or general atmospheric density is there at 200,000 feet? (Where we assume the shuttle began to break up).

Would it be enough to 'catch' on something, say an improperly sealed section in the landing gear system, and cause it to heat up or divert the path of the shuttle while it was turning?