There are two ways people find the number for specific impulse.

It had a specific impulse of nearly three hundred seconds, in fact.

The amount of fuel used to find specific impulse can be measured in different ways.

When specific impulse is measured as a speed, it has another name.

The most common way to measure specific impulse today uses seconds.

An engine with a higher specific impulse uses fuel better.

This means specific impulse can be used to compare engine performance in any country.

This allows it to achieve a specific impulse of 301s at the Earth's surface.

The higher the specific impulse, the more dazzling the engine.

For each stage the specific impulse may be different.