.
Orbital spaceflight requires a
satellite or
spacecraft payload to be accelerated to high velocity. In the vacuum of space, reaction forces must be provided by the ejection of mass, resulting in the
rocket equation. The physics of spaceflight are such that
rocket stages are typically required to achieve the desired orbit.
Expendable launch vehicles are designed for one-time use, with boosters that usually separate from their payload and disintegrate during
atmospheric reentry or on contact with the ground. In contrast,
reusable launch vehicles are designed to be recovered intact and launched again. The
SpaceX Falcon 9 is an example of a reusable launch vehicle. As of 2023, all reusable launch vehicles that were ever operational have been partially reusable, meaning some components are recovered and others are not. This usually means the recovery of specific stages, usually just the first stage, but sometimes specific components of a rocket stage may be recovered while others are not. The
Space Shuttle, for example, recovered and reused its
solid rocket boosters, the
Space Shuttle orbiter that also acted as a second stage, and the engines used by the core stage (the
RS-25, which was located at the back of the orbiter), however the fuel tank that the engines sourced fuel from, which was separate from the engines, was not reused. For example, the
European Space Agency is responsible for the
Ariane V, and the
United Launch Alliance manufactures and launches the
Delta IV and
Atlas V rockets.
Launch platform locations company
Orienspace Launchpads can be located on land (
spaceport), on a fixed ocean platform (
San Marco), on a mobile ocean platform (
Sea Launch), and on a
submarine. Launch vehicles can also be launched from the
air.
Flight regimes A launch vehicle will start off with its payload at some location on the surface of the Earth. To reach orbit, the vehicle must travel vertically to leave the
atmosphere and horizontally to prevent re-contacting the ground. The
required velocity varies depending on the orbit but will always be extreme when compared to velocities encountered in normal life. Launch vehicles provide varying degrees of performance. For example, a satellite bound for
Geostationary orbit can either be directly inserted by the
upper stage of the launch vehicle or launched to a
geostationary transfer orbit (GTO). A direct insertion places greater demands on the launch vehicle, while GTO is more demanding of the spacecraft. Once in orbit, launch vehicle upper stages and satellites can have overlapping capabilities, although upper stages tend to have orbital lifetimes measured in hours or days while spacecraft can last decades.
Distributed launch Distributed launch involves the accomplishment of a goal with multiple spacecraft launches. A large spacecraft such as the
International Space Station can be constructed by assembling modules in orbit, or in-space
propellant transfer conducted to greatly increase the
delta-V capabilities of a
cislunar or deep space vehicle. Distributed launch enables space missions that are not possible with single launch architectures. Mission architectures for distributed launch were explored in the 2000s and launch vehicles with integrated distributed launch capability built-in began development in 2017 with the
SpaceX Starship design. The standard Starship launch architecture is to refuel the spacecraft in
low Earth orbit to enable the craft to send high-mass payloads on more
energetic missions. == Return to launch site ==