[Pres Raygun]

The Enterprise, is not space worthy, because it was used for stress and vibration testing, which was so rigorous, that the airframe was damaged beyond repair.

[Charles Martel]

The Enterprise, is not space worthy, because it was used for stress and vibration testing, which was so rigorous, that the airframe was damaged beyond repair.

It is also the oldest of the lot. I suppose that it could be rebuilt, but it would take longer and be more expensive than just building a new orbiter. It does not seem terribly smart to start building another shuttle "from scratch" when the design can obviously be improved. I forget... was Enterprise ever "flown" to a landing after being carried aloft, or did it only ride on the Shuttle Transport aircraft?

[El Gato]

The Enterprise, is not space worthy, because it was used for stress and vibration testing, which was so rigorous, that the airframe was damaged beyond repair.

My understanding was that it was never intended to be spaceworthy and all the folks who petitioned and harranged NASA to name the first shuttle "Enterprise" were sorely disappointed, not to mention PO'd. I fell into the latter category myself.