Sub-orbital spaceflight in the context of "SpaceShipOne"

A spacecraft is a vehicle that is designed to fly and operate in outer space. Spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, planetary exploration, and transportation of humans and cargo. All spacecraft except single-stage-to-orbit vehicles cannot get into space on their own, and require a launch vehicle (carrier rocket).

On a sub-orbital spaceflight, a space vehicle enters space and then returns to the surface without having gained sufficient energy or velocity to make a full Earth orbit. For orbital spaceflights, spacecraft enter closed orbits around the Earth or around other celestial bodies. Spacecraft used for human spaceflight carry people on board as crew or passengers from start or on orbit (space stations) only, whereas those used for robotic space missions operate either autonomously or telerobotically. Robotic spacecraft used to support scientific research are space probes. Robotic spacecraft that remain in orbit around a planetary body are artificial satellites. To date, only a handful of interstellar probes, such as Pioneer 10 and 11, Voyager 1 and 2, and New Horizons, are on trajectories that leave the Solar System.

A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, peaking in number at an altitude around 800 km (500 mi), while the farthest in LEO, before medium Earth orbit (MEO), have an altitude of 2,000 kilometers, about one-third of the radius of Earth and near the beginning of the inner Van Allen radiation belt.

The term LEO region is used for the area of space below an altitude of 2,000 km (1,200 mi) (about one-third of Earth's radius). Objects in orbits that pass through this zone, even if they have an apogee further out or are sub-orbital, are carefully tracked since they present a collision risk to the many LEO satellites.

Victor Lance Vescovo (born February 10, 1966) is an American private equity investor, retired naval officer, sub-orbital spaceflight participant, and undersea explorer. He was a co-founder and managing partner of private equity company Insight Equity Holdings from 2000 to 2023. Vescovo achieved the Explorers Grand Slam by reaching the North and South Poles and climbing the Seven Summits. He visited the deepest points of all of Earth's five oceans during the Five Deeps Expedition of 2018–2019.

Space tourism is human space travel for recreational purposes. There are several different types of space tourism, including orbital, suborbital and lunar space tourism. Tourists are motivated by the possibility of viewing Earth from space, feeling weightlessness, experiencing extremely high speed and something unusual, and contributing to science.

Space tourism started in April 2001, when American businessman and engineer Dennis Tito became the first ever space tourist to travel to space aboard a Soyuz-TM32 spacecraft. During the period from 2001 to 2009, seven space tourists made eight space flights aboard a Russian Soyuz spacecraft to the International Space Station, brokered by American company Space Adventures in conjunction with Roscosmos and RSC Energia. Iranian-American businesswoman Anousheh Ansari became the first ever female space tourist in September 2006. The publicized price was in the range of US$20–25 million per trip. Some space tourists have signed contracts with third parties to conduct certain research activities while in orbit. By 2007, space tourism was thought to be one of the earliest markets that would emerge for commercial spaceflight.

A space launch is the phase of a spaceflight mission during which a launch vehicle reaches space. The launch may be sub-orbital or the launch may continue until the vehicle reaches orbit. A space launch begins at a launch pad, which may be on land or at sea, or when the launch vehicle is released mid-air from an aircraft.

A spaceport or cosmodrome is a site for launching or receiving spacecraft, by analogy to a seaport for ships or an airport for aircraft. The word spaceport—and even more so cosmodrome—has traditionally referred to sites capable of launching spacecraft into Earth's orbit or on interplanetary trajectories. However, rocket launch sites for sub-orbital spaceflights are also sometimes called spaceports, especially as new and proposed facilities for suborbital commercial spaceflight are often branded as "spaceports". Space stations and proposed future lunar bases are also sometimes referred to as spaceports, particularly when envisioned as nodes for further interplanetary travel.

Spaceports are evolving beyond traditional government-run complexes into multi-functional aerospace hubs, increasingly driven by private companies such as SpaceX, Blue Origin, and Virgin Galactic. A prominent example is Starbase, a private spaceport operated by SpaceX in Boca Chica, Texas. Starbase serves as the primary development and launch site for Starship, a fully reusable spacecraft designed for missions to the Moon, Mars, and beyond. The facility includes rocket production, launch, and landing infrastructure, and in May 2025, it was officially incorporated as a municipality in Texas—marking the first time a spaceport has become its own city. Starbase is now both a spaceport and a small residential and industrial community, primarily supporting SpaceX operations.

MW 18014 was a German A-4 test rocket launched on 20 June 1944, at the Peenemünde Army Research Center in Peenemünde. It was the first man-made object to reach outer space, attaining an apogee of 176 kilometres (109 mi), well above the Kármán line that was established later as the lowest altitude of space. It was a vertical test launch, and was not intended to reach orbital velocity, so it returned and impacted Earth, making it the first sub-orbital spaceflight.

Cygnus X-1 (abbreviated Cyg X-1) is a galactic X-ray source in the constellation Cygnus and was the first such source widely accepted to be a black hole. It was discovered in 1964 during a rocket flight and is one of the strongest X-ray sources detectable from Earth, producing a peak X-ray flux density of 2.3×10 W/(m⋅Hz) (2.3×10 jansky). It remains among the most studied astronomical objects in its class. The compact object is now estimated to have a mass about 21.2 times the mass of the Sun and has been shown to be too small to be any known kind of normal star or other likely object besides a black hole. If so, the radius of its event horizon has 300 km "as upper bound to the linear dimension of the source region" of occasional X-ray bursts lasting only for about 1 ms.

Cygnus X-1 is a high-mass X-ray binary system located about 7,000 light-years away, that includes a blue supergiant variable star. The supergiant and black hole are separated by about 0.2 AU, or 20% of the distance from Earth to the Sun. A stellar wind from the star provides material for an accretion disk around the X-ray source. Matter in the inner disk is heated to millions of degrees, generating the observed X-rays. A pair of relativistic jets, arranged perpendicularly to the disk, are carrying part of the energy of the infalling material away into interstellar space.