specific impulse
noun
: the thrust produced per unit rate of consumption of the propellant that is usually expressed in pounds of thrust per pound of propellant used per second and that is a measure of the efficiency of a rocket engine
Examples of specific impulse in a Sentence
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Essentially, a nuclear rocket engine is a reactor that has hydrogen running through it as a propellant, which is heated to an astonishing 3,000 K (2,727 °C, 4,940 °F), giving it almost twice the efficiency in terms of thrust and specific impulse as a chemical rocket.
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David Szondy
september 10, New Atlas, 10 Sep. 2025
Ideally, the engine should be able to produce high specific impulse while also satisfying the high thrust and low engine mass requirements.
—Dan Kotlyar, Discover Magazine, 5 Oct. 2024
And this is where SEP shines: the specific impulse of these Hall effect thrusters is 3000 seconds.
—IEEE Spectrum, 30 Mar. 2015
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David Szondy
september 10, New Atlas, 10 Sep. 2025
Ideally, the engine should be able to produce high specific impulse while also satisfying the high thrust and low engine mass requirements.
—Dan Kotlyar, Discover Magazine, 5 Oct. 2024
And this is where SEP shines: the specific impulse of these Hall effect thrusters is 3000 seconds.
—IEEE Spectrum, 30 Mar. 2015
Cite this Entry
“Specific impulse.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/specific%20impulse. Accessed 15 Sep. 2025.
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