I have to admit, I won't really miss the Space Shuttle. If a camel is a horse designed by committee, the Shuttle must have been their next assignment.
Prior to the Shuttle, astronauts jettisoned everything except for a small capsule which splashed down in an ocean and had to be recovered by an aircraft carrier. The Shuttle began as a design for a craft that could be controlled during reentry and land on a conventional airstrip. The early design used a dynamic lifting body (it could glide without wings) and had the code name "dynasore". A version of this piloted by Tony Stark made a cameo in a Nick Fury, Agent of SHIELD comic in the mid-1960s.
Then the committee got a hold of it. It was bad PR to abandon so much of a spacecraft so NASA decided that their new craft would have as many reusable parts as possible. That included the rocket engine which was one of the most complex parts. At the same time, NASA was planning for a space station and wanted a space truck to ferry building material and personnel to and from orbit. The plan was to have something that could be quickly serviced and reused. Plans called for a fleet that could support monthly launches.
The Shuttle took shape. Budget cuts meant that it had to use an external fuel tank. This required a pair of solid state booster rockets to help get it off the ground. Once in the sky, it would roll onto its back so that the Shuttle could support the fuel tank. That is why the engines seem to point up at a strange angle.
This design led to the destruction of two shuttles and the death of their crews. It turned out that the booster rockets were sensitive to cold. When launched in freezing weather, an O-ring could fail allowing hot gas to burn through the booster and ignite the fuel in the main tank. Also, with the tank full of liquid oxygen strapped to the belly of the Shuttle, the inevitable ice that formed could (and did) hit the Shuttle, damaging the critical heat shielding.
For those worried about the suspension of manned American space shots, it happened in the 1970s, also. The Shuttle took longer to build than expected leaving a gap of several years without an American presence in space.
By the time the Shuttle launched, the space station that it was to service had been cut from the budget. NASA went ahead with the Shuttle on the theory that, as long as they had a space truck, they would eventually get approval for a station to fly to. In the meantime it struggled to find a mission. NASA offered it as a platform for launching satellites but had to subsidize launches in order to keep them competitive.
The concept of a reusable spacecraft making flights cheaper never really paid off. The Shuttle still needed expensive maintenance after every flight and an army of support staff. Just look at the news stories about unemployment on Florida's "Space Coast" to see where the real expense of operating the Shuttle went.
Also, the one-size-fits-all approach meant that the Shuttle was often bigger than required for a job. When every ounce adds high costs, this is a problem.
But the Shuttle's biggest problem is that it never became safe and reliable. With two shuttles destroyed out of 135 missions, it is one of the most dangerous vehicles in use in decades. The problems that destroyed the Columbia were never solved, only minimized.
The Shuttles are vehicles conceived of in the 1960s, designed in the 1970s and built in the 1970s & 1980s. They are overdue for retirement. Operating the Shuttles as long a they did kept NASA concentrated on low-earth orbit instead of deep space exploration. Here's hoping that they return to their roots.