Wiktionary
n. A reaction engine that obtains thrust by jet propulsion which forms its jet exclusively from propellant.
WordNet
n. a jet engine containing its own propellant and driven by reaction propulsion [syn: rocket]
Wikipedia
A rocket engine is a type of jet engine that uses only stored rocket propellant mass for forming its high speed propulsive jet. Rocket engines are reaction engines, obtaining thrust in accordance with Newton's third law. Most rocket engines are internal combustion engines, although non-combusting forms (such as cold gas thrusters) also exist. Vehicles propelled by rocket engines are commonly called rockets. Since they need no external material to form their jet, rocket engines can perform in a vacuum and thus can be used to propel spacecraft and ballistic missiles.
Compared to other types of jet engines, rocket engines have the highest thrust, are by far the lightest, but are the least propellant efficient (have the lowest specific impulse). The ideal exhaust is hydrogen, the lightest of all gases, but chemical rockets produce a mix of heavier species, reducing the exhaust velocity. Rocket engines become more efficient at high velocities (due to greater propulsive efficiency and Oberth effect). Since they do not require an atmosphere, they are well suited for uses at very high altitude and in space.
Usage examples of "rocket engine".
Powered by a liquid-fuel rocket engine, it accelerated to nine hundred knots and began its descent, its radar-homing head tracking on a preprogrammed target area ten miles wide.
Well, says Joe Walker, we've got a 57,000-pound rocket engine now, and the Redstone that shoots your little peapod up there only puts out 78,000, so we're almost up with you—.
They gave advance notification of launches only on condition that nothing would be published until there was 'fire in the tail', which meant that the rocket engine had been ignited.
At this point the solid-fuel rocket engine fires, the blast of exhaust gas flares out the retractable tail fins, and the missile accelerates to four times the speed of sound.
Like the old Apollo landers, it had a single fixed rocket engine that was driving the ascent, and it was fitted with attitude control jets at every corner to turn it and control its trajectory.
The strapmini-rocket engine had not yet fired-it was flying over thousand feet higher than programmed, and the extra altitu meant a longer unassisted gliding ability The infrared orange laser site slowly began to enlarge as got closer-the Striker was locked onto a huge power substation.
Smoke and flames spewed out the opening like an upside-down rocket engine.
The first tanker would not be so equipped, but the second tanker through its robot would smell out the first and home on it with a pint-sized rocket engine, using the smallest of vectors to bring them together.
The first tanker would not be so equipped, but th~ second tanker through its robot would smell out the first and home on it with a pint-sized rocket engine, using the smallest of vectors to bring them together.