How much of the Shuttle was reused

[rpayne88]

Just about everyone here knows that the external tank was the only major expendable component on the shuttle. What other components, such as thermal tiles and SRB nosecones and parachutes, were expended/ discarded after flight?

[Nibb31]

The thermal tiles were reused. They were only replaced if they were damaged. There were all sorts of covers and shrouds there were expended too.

The SSME engines were removed, serviced, and reused in rotation.

The SRB casings were refurbished and reused, but they were pretty much just steel shells that weren't worth much. The nosecones and parachutes were discarded, and so were the nozzles.

Edited December 4, 2013 by Nibb31

[Murph]

I seem to remember that there was some debate about the cost benefit from re-using the SSMEs, as the servicing was extensive, close to a full rebuild, with many parts replaced. I think there was a cost benefit, but it wasn't as big as originally hoped vs. single use engines. I can't cite a source for that, just pretty sure I read or saw that somewhere.

[jwenting]

Murph, many such things, where the cost benefit expected evaporated in reality, were a major reason why the Shuttle never lived up to its promise.

[Nibb31]

No, the SSMEs were removed, serviced and tested after each flight, but were completely overhauled after a certain number of flights (I don't remember how many).