The Shuttle is inspiring, and compared to nothing it looks excellent. But on the whole it is not a good system. It has unique capabilities that it uses extremely rarely or not at all (such as the cross-range flight ability) but which impose tremendous compromises on the system's cost, reliability, and safety.<p>All of this added up to the system falling far, far short of its design goals in payload cost and flight rate, by nearly 2 orders of magnitude. By any sound measure the Shuttle is a failed experiment that was left to run, and bleed NASA budgets dry, for far too long. On the whole each Shuttle mission cost $1.6 billion dollars.<p>The alternative to not building the Shuttle was continuing with what we had before, which even at a reduced budget compared to the Shuttle would have resulted in larger space stations, moon bases, and perhaps manned Mars missions. The alternative now to not continuing the Shuttle is relying on commercial launch providers as the base of manned spaceflight, which looks to be both cheaper and more capable than the Shuttle.