The Shuttle was amazingly effective. It succeeded in most of its original mission objectives. It conducted hundreds of scientific missions, launched and repaire

The Shuttle was amazingly effective. It succeeded in most of its original mission objectives. It conducted hundreds of scientific missions, launched and repaired Hubble, and built the ISS (originally Freedom). The "cost" of Shuttle launches was calculated as NASA's entire manned spaceflight budget divided by the number of scheduled launches. They paid salaried staff all year no matter how many launches happened. That cost was trending downward as the number of launches increased prior to the Challenger disaster. After return to flight after Challenger NASA cut the launch schedule but had to pay the same infrastructure costs so Shuttle flights got more "expensive".