specific impulse

noun

, Rocketry.

1. a measure, usually in seconds, of the efficiency with which a rocket engine utilizes its propellants, equal to the number of pounds of thrust produced per pound of propellant burned per second.
2. the specific impulse that a given combination of propellants would produce in an ideal rocket engine providing complete combustion, no friction losses, and no lateral expansion of the exhaust.

specific impulse

noun

1. the ratio of the thrust produced by a rocket engine to the rate of fuel consumption: it has units of time and is the length of time that unit weight of propellant would last if used to produce one unit of thrust continuously

Word History and Origins

Origin of specific impulse¹

First recorded in 1945–50

Example Sentences

"A new concept for in-space propulsion is proposed in which propellant is not ejected from the engine, but instead is captured to create a nearly infinite specific impulse," Burns wrote in the paper's abstract.

From Fox News

My interpretation of the definitions of specific impulse and mass ratio especially seemed to impress him.

From Literature

But we were missing an important number—the specific impulse of zincoshine.

From Literature

Every day I honed my spiel a little more so that I could quickly deliver a learned presentation on the mathematics of the design of De Laval nozzles, the calculations of specific impulse and mass ratios, and the trigonometry of altitudes needed for an amateur rocketry test range.

From Literature

Specific impulse was, my book said, the thrust a rocket produced when it burned a pound of fuel in one second.

From Literature