Sustainer engine

{{Short description|Engines that remain on a rocket after rocket booster separation}}

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Image:STS-1 The Shuttle's Solid Rocket Boosters break away from Columbia's External Tank.jpg's three Main Engines act as sustainers]]

A sustainer engine is a rocket engine which remains with a spacecraft during its ascent after booster engines have separated from the spacecraft.{{cite web | url=https://www.grc.nasa.gov/WWW/K-12/rocket/rktstage.html | title=Rocket Staging }}

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