You make some interesting points. I'm not sure what the failure rate would have been if the Apollo program were allowed to continue with the same design (albei

You make some interesting points. I'm not sure what the failure rate would have been if the Apollo program were allowed to continue with the same design (albeit better materials and engineering), but its probably incorrect to assume it would be the same for the two craft because they are fairly different designs and have different physics (i.e Shuttle rocking back and forth before launch is due to its "piggybacking"). However the two most significant design changes that would have reflected far different failure rates are: 1) Change in fuel type and 2) Presence of an abort sequence. 1) In the Apollo design, the rocket was liquid propelled, thus it could have been shut off (theoretically) at any point in the launch sequence. The Space Shuttle by contrast has Solid Rocket Boosters, which once lit, do not turn off. 2) The Apollo rocket had an escape rocket mounted to the capsule that could have been fired and brought the crew to safety in the event that 1) did not occur. The Space Shuttle by contrast cannot enter into an abort sequence until those SRB's are done firing.