In Star Trek: Voyager, what experimental drive lets a starship travel faster than conventional warp?

In Star Trek: Voyager, the quantum slipstream drive is an experimental propulsion system that can move a starship faster than conventional warp travel.

Voyager encounters quantum slipstream technology in “Hope and Fear,” where an alien vessel offers a supposedly revolutionary way to shorten the ship's journey home. The drive creates a quantum field and allows a vessel to follow a narrow corridor through space at extraordinary speed.

The technology is not a routine Federation system. Voyager cannot safely use it without a suitable slipstream-capable vessel and compatible calculations. Later stories connect quantum slipstream with Starfleet's continuing search for faster long-distance travel.

It is easy to confuse quantum slipstream with transwarp. Both describe very rapid travel, but they are different fictional technologies with different histories and mechanisms. The spore drive belongs to Star Trek: Discovery and uses mycelial pathways, so it is not Voyager's experimental drive.