[Vic3O3]

and the orbiter was designed for 100 missions.

I suspect that 100-mission plan per orbiter is way out of line with reality. Since in a fleet of 5 (counting the replaced Challenger) Columbia had the most flight time with 28 missions, in a 22 yr service life...If they were REALLY planning on flying each orbiter 100 times, at this rate each orbiter would have ended it's service life at 100+ years of age! Ridiculous! I suspect the 100-mission profile was strictly for Congressional Funding purposes.

[The Electrician]

If they were REALLY planning on flying each orbiter 100 times, at this rate each orbiter would have ended it's service life at 100+ years of age! Ridiculous! I suspect the 100-mission profile was strictly for Congressional Funding purposes.

The Shuttles have been flying considerably fewer missions per year than originally planned. Of course, skeptics could say that the original plan was also fiction invented for misleading Congress.

[Truth29]

"I suspect that the 100-mission profile was strictly for Congressional Funding purposes."

Perhaps, but the original plans were for far more flights per year and included many commercial payload missions. Various technical difficulties and the loss of the Challenger changed all of that.

[ContemptofCourt]

The original plan was for each shuttle to fly 10 missions a year. That was the whole idea of the "space truck" concept. One month turnaround time and a $5 million launch.

They only missed by $495 million dollars and 9 missions a year....

[cinFLA]

You premis on launch cycle rates is based on history; not the rate that was planned. Thus your "lifetime" figure is off.