A couple of random thoughts:

Is it practical for the Russians to re-use Soyuz landing modules? It seems like it was in pretty good shape after the landing. Or is it just cheaper in the long run to build a new one rather than refurbish a used one for another flight.

Had the shuttle system been built with the shuttle on top of the stack instead of on the side, ignoring that it wasn't practical with that design, then both Challenger and Columbia might still be in one piece. Their destructions were both caused by ET associated problems. I know Challengers primary cause was the SRB, but had it not been on the side of the ET the crew may have survived. Having the orbiter on the side of the ET made it vulnerable to the explosion, and to debris "foam" falling off of the tank. After, all the reason for the foam was to prevent ice build-up being a hazard to the orbiter. Had the design somehow been with the orbiter on top, there would have been no need for the foam. I know this is just hindsight. All those questions must have been gone over and over many times during the design process.