Criticism of the Space Shuttle program stemmed from claims that NASA's Shuttle program failed to achieve its promised cost and utility goals, as well as design, cost, management, and safety issues. More specifically, it failed in the goal of reducing the cost of space access. Space Shuttle incremental per-pound launch costs ultimately turned out to be considerably higher than those of expendable launchers.
By 2011, the incremental cost per flight of the Space Shuttle was estimated at $450 million, or $18,000 per kilogram (approximately $8,000 per pound) to low Earth orbit (LEO). By comparison, Russian Proton expendable cargo launchers (Atlas V rocket counterpart), still largely based on the design that dates back to 1965, are said to cost as little as $110 million, or around $5,000/kg (approximately $2,300 per pound) to LEO.
When all design and maintenance costs are taken into account, the final cost of the Space Shuttle program, averaged over all missions and adjusted for inflation, was estimated to come out to $1.5 billion per launch, or $60,000/kg (approximately $27,000 per pound) to LEO. This should be contrasted with the originally envisioned costs of $118 per pound of payload in 1972 dollars (approximately $657 per pound adjusting for inflation to 2013).
It failed in the goal of achieving reliable access to space, partly due to multi-year interruptions in launches following Shuttle failures. NASA budget pressures caused by the chronically high NASA Space Shuttle program costs have eliminated NASA manned space flight beyond low earth orbit since Apollo, and severely curtailed use of unmanned probes. NASA's promotion of and reliance on the Shuttle slowed domestic commercial expendable launch vehicle (ELV) programs until after the 1986 Challenger disaster.
"Space Transportation System" (NASA's formal name for the overall Shuttle program) was created to transport crewmembers and payloads into low Earth orbits. It would afford the opportunity to conduct science experiments on board the shuttle to be used to study the effects of space flight on humans, animals and plants. Other experiments would study how things can be manufactured in space. The shuttle would also enable astronauts to launch satellites from the shuttle and even repair satellites already out in space. The Shuttle was also intended for research into the human response to zero-g.