Spaceplane

The history of the spaceplane traces back to the early days of space travel, though it took some time for it to become the ubiquitous mode of orbital passenger transportation it is today. Using some form of glider for reentry instead of blunt capsules and parachutes was studied even before the first people reached orbit, though it only was realize in 1981 with the launch of the first Buran orbiter. These spacecraft were carried into orbit by a separate, disposable rocket. This style of vessel coexisted with the original booster-and-capsule design for some time, into the beginnings of commercial passenger space travel. Launching into space was an unpleasant experience in those days, being violently accelerated upwards by a large rocket.
The next big innovation were air launched spaceplanes. They were carried to height by larger aircraft, were they ignited their rocket engines and accelerated to orbital speeds in a steep climb. The horizontal takeoff greatly increased passenger comfort, though the need for a carrier aircraft limited the spaceplanes' sizes and thus capacity.
The big breakthrough was the invention of hybrid rocket engines in the 2000s. These can operate with atmospheric oxygen at lower altitudes, and then switch to an internal supply once the air gets too thin. Using such engines, a spaceplane can take off from a runway and reach orbit in a single stage. With time these single-stage-to-orbit space planes became so refined, that in terms of noise and turbulence they don't feel much different to the passengers than regular air travel.