Star Trek Expanded Universe

The impulse drive was a sublight propulsion system used on starships, including, but not limited to, relativistic speeds.

The term "impulse drive" was allegedly derived from "internally-metered pulse drive" (TOS novel: Final Frontier), though in real life, this was probably a retronym.

The first significant use of an impulse drive was on the Lewis and Clark expedition to Saturn in 2018. (TOS novel: The Rings of Time)

At least by the 2360s, impulse drive created an low-level subspace field around the vessel. (Star Trek: The Next Generation Technical Manual)

This was contrived to explain why the impulse engines on Galaxy-class explorer's primary hulls were off the fore-aft axis of the ship -- and the starship didn't tumble.

Stoneship-class starships could fly at 3/4 of the speed of light at full impulse. (Star Trek: The Stoneship Files: "Highly Illogical")


Impulse drive was essentially a fusion-powered rocket, usually powered with one or more fusion reactors. These reactors created plasma, who was then exhausted outside the ship, propelling it. (Star Trek: The Stoneship Files: "Dilithium Dance")

External links[]