Launch Vehicle

launch vehicle

Rocket system that boosts a spacecraft into Earth orbit or beyond Earth's gravitational pull. A wide variety of launch vehicles have been used to lift payloads ranging from satellites weighing a few pounds (or kilograms) to large modular components of space stations. Most launch vehicles are expendable (one-use) systems; many early ones were derived from intercontinental ballistic missiles (see ICBM). The Saturn V, which launched the spacecraft that carried humans to the Moon (see Apollo), had three stages (see staged rocket). The U.S. space shuttle system (from 1981) represents a significant departure from expendable launch vehicles in that it is partially reusable—its manned orbiting component is designed for numerous flights, and its solid rocket boosters can be recovered and refurbished.

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launch vehicle [′lȯnch ‚ve·ə·kəl]

(aerospace engineering)

A rocket or other vehicle used to launch a probe, satellite, or the like. Also known as booster.

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Launch Vehicle 

a multistage (two- to four-stage) rocket used to lift artificial earth satellites, unmanned space probes, manned spacecraft, orbital stations, and other payloads into space. Depending on the performance characteristics and the capability of injecting a payload of a given weight into orbit, launch vehicles can be classified as light (up to 500 kg), medium (up to 10 tons), heavy (up to 100 tons), and extra heavy (more than 100 tons). Most launch vehicles are based on intercontinental or intermediate-range ballistic missiles.

The fuel components generally used in the first stage of a launch vehicle are kerosine and liquid oxygen; this combination is used in the Vostok (USSR) and the Atlas-Agena (USA) rockets. The liquid-propellant rocket engines of the upper stages usually operate on high-energy fuels; examples are the Cosmos (USSR), the Atlas-Agena (USA), and the Titan 2 (USA) rockets. The upper stages may also operate on liquid hydrogen and liquid oxygen, as do the Atlas-Centaur and the Saturn 5 (USA) rockets.

A distinctive feature of the final stages of some launch vehicles is the possibility of restarting their engines; this permits maneuvering to change the altitude and inclination of the orbit and to launch a payload from an earth orbit. In addition to liquid-propellant rocket engines used as the main engines in the majority of launch vehicles, solid-propellant booster engines are sometimes attached to the first-stage housing, as in the case of the Thrust-Augmented Thor-Agena (USA) rocket.

Payloads ranging in weight from several kg to several tens of tons can be placed in circular earth orbits with the required velocity using launch vehicles. All launch vehicles are characterized by a relatively small weight and a large fuel capacity (the weight of the fuel is between 85 and 90 percent of the rocket’s launch weight). The launch weight ranges from several tens of tons up to several thousand tons. The duration of the powered flight trajectory of some launch vehicles is more than 17 min. The flight covers a wide altitude range.

G. A. NAZAROV