In spaceflight, a launch vehicle or carrier rocket is a rocket used to carry a payload from the Earth's surface into outer space. Spaceflight is the use of Space technology to fly a Spacecraft into and through Outer space. A rocket or rocket vehicle is a Missile, Aircraft or other Vehicle which obtains Thrust by the reaction of the Outer space, often simply called space, comprises the relatively empty regions of the Universe outside the escape velocities of Celestial bodies. A launch system includes the launch vehicle, the launch pad and other infrastructure. A launch pad is the area and facilities where rockets or spacecrafts liftoff [1] Usually the payload is an artificial satellite placed into orbit, but some spaceflights are sub-orbital while others enable spacecraft to escape Earth orbit entirely. This article is about artificial satellites For natural satellites also known as moons see Natural satellite. In Physics, an orbit is the gravitationally curved path of one object around a point or another body for example the gravitational orbit of a planet around a star A sub-orbital spaceflight (or sub-orbital flight is a Spaceflight in which the Spacecraft reaches space, but its Trajectory intersects A spacecraft is a Vehicle or machine designed for Spaceflight. In Physics, escape velocity is the speed where the Kinetic energy of an object is equal to the magnitude of its Gravitational potential energy A launch vehicle which carries its payload on a suborbital trajectory is often called a sounding rocket. A sounding rocket, sometimes called a research rocket, is an instrument-carrying Rocket designed to take measurements and perform scientific experiments during
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Types of launch vehicles
Expendable launch vehicles are designed for one-time use. An expendable launch system is a Launch system that uses an expendable launch vehicle (ELV to carry a payload into Space. They usually separate from their payload, and may break up during atmospheric reentry. Reusable launch vehicles, on the other hand, are designed to be recovered intact and used again for subsequent launches. A reusable launch system (or reusable launch vehicle, RLV is a Launch system which is capable of launching a Launch vehicle into space more than once For orbital spaceflights, the Space Shuttle is currently the only launch vehicle with components which have been used for multiple flights. An orbital spaceflight (or orbital flight is a Spaceflight in which a Spacecraft is placed on a trajectory where it could remain in space for at least NASA 's Space Shuttle, officially called the Space Transportation System ( STS) is the Spacecraft currently used by the United States
Launch vehicles are often characterized by the amount of mass they can lift into orbit. For example, a Proton rocket has a launch capacity of 22,000 kg (48,500 lbs. The Proton rocket ) to low Earth orbit (LEO). A Low Earth Orbit (LEO is generally defined as an Orbit within the locus extending from the Earth’s surface up to an altitude of 2000 km
Launch vehicles are also characterized by the number of stages they employ. Rockets with as many as five stages have been successfully launched, and there have been designs for several single-stage-to-orbit vehicles. A single-stage-to-orbit (or SSTO) vehicle reaches Orbit from the surface of a body without jettisoning hardware expending only propellants and fluids Additionally, launch vehicles are very often supplied with boosters. These supply high thrust early on in the flight in parallel with other engines on the vehicle. Boosters allow the remaining engines to be smaller which reduces the stages burnout mass and thus allows for bigger payload.
Other frequently-reported characteristics of launch vehicles are the nation or space agency responsible for the launch, and the company or consortium that manufactures and launches the vehicle. As examples, the European Space Agency is responsible for the Ariane V, and the United Launch Alliance manufactures and launches the Delta IV. The European Space Agency ( ESA) established in 1975 is an intergovernmental organisation dedicated to the exploration of space, currently with 17 member Ariane 5 is a European Expendable launch The Delta IV is a family of Delta Rockets designed by Boeing 's Integrated Defense Systems division and built in United Launch Alliance's Many launch vehicles are considered part of an historical line of vehicles which share a name. For example, the Atlas V is the latest member of the Atlas rocket family. The Atlas V Rocket is an Expendable launch vehicle formerly built by Lockheed Martin and now built by the Lockheed Martin- Boeing joint venture Atlas is a family of US space Launch vehicles The original Atlas missile was designed in the late 1950s
Non-rocket spacelaunch‎ alternatives are at the planning stage. Non-rocket spacelaunch (NRS is the idea of reaching outer space specifically from the Earth's surface predominately without the use of conventional chemical rockets which today
Vehicle assembly
Various methods, each with specialized equipment, are used to get an assembled launch vehicle on its launch pad. In some launch systems, like Delta II, the vehicle is assembled vertically on the pad, using a crane to hoist each stage into place. The Space Shuttle orbiter, external tank, and solid rocket boosters are assembled vertically in the Vehicle Assembly Building and then a special crawler-transporter moves the entire stack upright to the launch pad. NASA 's Space Shuttle, officially called the Space Transportation System ( STS) is the Spacecraft currently used by the United States VABConstructionjpg|thumbnail|right|VAB during its early steel construction phase (1963 along with the Mobile Launcher Platform and tower assemblies for the Saturn V rocket The crawler-transporter is a tracked Vehicle used to transport the Saturn V Rocket, the Saturn IB rocket during Skylab The Soyuz rocket is assembled horizontally in a processing hangar, transported horizontally, and then brought upright once at the pad. The Soyuz launch vehicle (Western designation A-2 is an Expendable launch system manufactured by TsSKB-Progress in Samara Russia.
These assembly activities take place as part of the overall launch campaign for the vehicle. In the context of spaceflight a launch campaign is the set of activities which prepare a Launch vehicle for lift-off
Derivation and related terms
The term derives from the American satellite program, Project Vanguard, as a contraction of the phrase "Satellite Launching Vehicle" abbreviated as "SLV" as a term in the list of what the rockets were allocated for: flight test, or actually launching a satellite. Project Vanguard was a program managed by the United States Naval Research Laboratory (NRL which intended to launch the first Artificial satellite into The contraction would also apply to rockets which send probes to other worlds or the interplanetary medium.
In the English language, the phrase carrier rocket was used earlier, and still is in some circles in Britain. In Spaceflight, a launch vehicle or carrier rocket is a Rocket used to carry a payload from the Earth's surface into Outer space. A translation of that phrase is used in German, Russian, and Chinese. The U. S. Air Force detested the term carrier, which would refer to their competition, the aircraft carriers of the U. An aircraft carrier is a Warship designed with S. Navy. For this reason they called one airplane which carried another a conveyor.
Suborbital launch vehicles
Current suborbital launch vehicles include Spaceship one. SpaceShipOne is a Spaceplane that completed the first privately funded Human spaceflight on June 21, 2004.
Orbital Launch vehicles
Orbital launch
- See also: Orbital spaceflight
The delta-v needed for orbital launch is generally between 9300 and 10,000 m/s, although there is no upper limit. An orbital spaceflight (or orbital flight is a Spaceflight in which a Spacecraft is placed on a trajectory where it could remain in space for at least In Astrodynamics, the term delta-v, literally "change in velocity" (see symbol delta) has a specific meaning it is a Scalar which takes
The delta-v needed can be considered to be a combination of air-drag (determined by ballistic coefficient), gravity losses, altitude gain and the horizontal speed necessary to give a suitable perigee. The ballistic coefficient ( BC) of a body is a measure of its ability to overcome air resistance in flight In Astrodynamics and Rocketry, gravity drag (or gravity losses) is the difference between the Delta-v expended and the actual change in speed Potential energy can be thought of as Energy stored within a physical system The kinetic energy of an object is the extra Energy which it possesses due to its motion
Minimising air-drag means having a reasonably high ballistic coefficient which generally means having a launch vehicle about 10-20m long (longer still for hydrogen fueled stages as hydrogen has low density), as well as leaving the atmosphere early on in the flight, giving an air drag of around 300 m/s.
The horizontal speed necessary is around 7800 m/s.
The delta-v for altitude gain varies, but is around 2 km/s for 200 km altitude.
The calculation of the total delta-v for launch is complicated and in nearly all cases numerical integration is used; adding the delta-v's gives a pessimistic result since the rocket can thrust at an angle to reach orbit, which saves fuel as it can gain altitude and horizontal speed simultaneously.
Regulation
Under international law, the nationality of the owner of a launch vehicle determines which country is responsible for any damages resulting from that vehicle. Due to this, some countries require that rocket manufacturers and launchers adhere to specific regulations to indemnify and protect the safety of people and property that may be affected by a flight.
In the US any rocket launch that is not classified as amateur, and also is not "for and by the government," must be approved by the Federal Aviation Administration's Office of Commercial Space Transportation (FAA/AST), located in Washington, DC
Calendar of upcoming launches
Spaceflight Now maintains a "Worldwide launch schedule" listing upcoming launches. The Federal Aviation Administration ( FAA) is an agency of the United States Department of Transportation with authority to regulate and oversee all aspects of The Office of Commercial Space Transportation (generally referred to as FAA/AST or simply AST is the branch of the United States Federal Aviation Administration (FAA This is a timeline of known Spaceflights, both manned and unmanned sorted chronologically by launch date Please do not forget to move the "" tag if the next [2]
References
- ^ See for example: NASA Kills 'Wounded' Launch System Upgrade at KSC. Florida Today.
- ^ Worldwide launch schedule. Spaceflight Now.
See also
- List of human spaceflights
- List of launch vehicles
- Timeline of spaceflight
- Rocket launch
- Space Exploration