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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In principle, a CNTR rocket can double the specific impulse provided by previous nuclear thermal rocket designs dating back to the 1950s (and still being worked on by NASA and DARPA today) as well as quadruple that which can be achieved by chemical rockets.
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Keith Cooper, Space.com, 24 Sep. 2025
Where a solid fuel rocket has a specific impulse – a measure of rocket efficiency – of about 240 seconds, the SFJR can manage 1,000 seconds.
—New Atlas, 24 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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Keith Cooper, Space.com, 24 Sep. 2025
Where a solid fuel rocket has a specific impulse – a measure of rocket efficiency – of about 240 seconds, the SFJR can manage 1,000 seconds.
—New Atlas, 24 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 4 Oct. 2025.
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