Glossary · term

Specific impulse

Machines

Aliases
Isp
Domain
Machines

Definition

How much thrust a rocket gets per unit of propellant per second, in seconds: 250–300 for solids, up to 450 for hydrogen–oxygen. The rocket equivalent of fuel economy.

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From the Glossary database in Notion, last edited 2026-08-17. This page is the row, rendered by the build; nothing on it is written by hand.