The Space Transportation System (STS) is another name for the NASA Space Shuttle and Space Shuttle program. However, the name originates from, and can describe a more elaborate set of spacefaring hardware in the 1970s, although this meaning is obscure. For example, there was at one time a Mars exploration program called Voyager, but this was later obscured by the Voyager program, which launched two planetary space probes.

The other STS was a system of reusable manned space vehicles envisioned by NASA in the early 1970s to support extended operations beyond the Apollo program. Its major components consisted of an Earth Orbit Shuttle; a chemically-propelled "space tug" which could be used for low-to-high Earth orbit or Earth-to-lunar orbit transfers, and as a lunar orbit-to-surface shuttle; and a nuclear-powered interplanetary shuttle vehicle for flights to the planets Venus and Mars. The transportation system would support, and in turn be supported by, Earth and lunar orbital space stations and propellant depots.

A transport network, or transportation network in American English, is typically a network of roads, streets, pipes, aqueducts, power lines, or nearly any structure which permits either vehicular movement or flow of some commodity.

A transport network is used for transport network analysis to determine the flow of vehicles (or people) through it within the field of transport engineering, typically using mathematical graph theory. It may combine different modes of transport, for example, walking and car to model multi-modal journeys.

Spaceflight (also written space flight) is ballistic flight into or through outer space. Spaceflight can occur with spacecraft with or without humans on board. Examples of human spaceflight include the Russian Soyuz program, the U.S. Space shuttle program, as well as the ongoing International Space Station. Examples of unmanned spaceflight include space probes which leave Earth's orbit, as well as satellites in orbit around Earth, such as communication satellites. These operate either by telerobotic control or are fully autonomous.

Spaceflight is used in space exploration, and also in commercial activities like space tourism and satellite telecommunications. Additional non-commercial uses of spaceflight include space observatories, reconnaissance satellites and other earth observation satellites.

A spaceflight typically begins with a rocket launch, which provides the initial thrust to overcome the force of gravity and propels the spacecraft from the surface of the Earth. Once in space, the motion of a spacecraft—both when unpropelled and when under propulsion—is covered by the area of study called astrodynamics. Some spacecraft remain in space indefinitely, some disintegrate during atmospheric reentry, and others reach a planetary or lunar surface for landing or impact.