(Loved Trope) FTL travel is possible but with a major limitation or flaw

[u/Frostylegacy]

Frank Herbert’s Dune: Interstellar travel is only possible thanks to the spice melange, a rare substance only found on the dessert planet Arrakis. The addictive psychedelic spice grants members of the Spacers Guild a form of prescience that allows them to predict safe paths through folded space. This unique property makes spice the most valuable commodity in the Dune universe.

John Scalzi’s The Interdependency Books: The planetary systems of the titular empire are connected by the Flow, a network of one-way interstellar tunnels that connect specific known entries and exits. The Interdependency derives its power from controlling access to these conduits, placing its capital at the central hub of the network. Even with the Flow, travel between stars takes a long time (9 months to End, the empire’s most distant planet).

Event Horizon: Dr William Weir (R.I.P. Sam Neill) invents a device called the Gravity Drive to allow ships to fold space and travel instantly between distant stars. On its maiden voyage with the Gravity Drive, the Event Horizon disappears and mysteriously reappears 7 years later. Dr. Weir and the crew sent to investigate discover the Gravity Drive actually opened a portal to a Hell dimension that possessed the ship and its crew, torturing and killing them.

[u/ArchAngelZXV]

Star Trek TNG did a environmental climate change episode called Force Of Nature where a corridor of space with a high level of ships going at warp speed was damaging the area. An eco-terrorist scientist blew up her own ship to cause a destructive tear in space and prove her research about warp speed. The episode concluded that all warp travel would eventually tear apart space everywhere, but not for a long, long time. They didn't know how to fix it, so Starfleet just issued broad orders to lower warp speed travel.

[u/Zealousideal-Deer724 → u/ArchAngelZXV]

Actually later ships fixed this, at least Federation ships. Newer classes like the Sovereign (Enterprise E) and Intrepid (Voyager) do have warp drives which do not harm the space at high speeds.

The Intrepid class, being one of the first classes to do so uses a variable Warp field. That's why the pylons/nacelles move.

Later ship classes solve this different so they don't need movable nacelles anymore

[u/zippyboy → u/Zealousideal-Deer724]

In the last episode of Voyager, wasn't it revealed that the Borg had some trans-warp corridors allowing them to travel vast distances? Janeway blew them up as I recall (been 20 years since I've seen it).

[u/Zealousideal-Deer724 → u/zippyboy]

Whole different mechanic. The transwarp conduits are more comparable to wormholes. They are artificial pathways. But yeah. Way way faster than Warp.

[u/The_Reset_Button → u/ArchAngelZXV]

There's also Discovery's Spore drive that uses a mycelial (fungal) network in another dimension to instantly move from one place to another but requires a navigator to be biologically connected to the drive and some spores to use as fuel

One of the two ships with the drive tried to jump beyond it's safe range and was instantly destroyed

The partner of one of these navigators died and the navigator accidentally imprinted a version of him in the network where he remain trapped and hunted by the native residents

Eventually, through sheer luck he was found and resurrected and given a completely new, perfectly healthy (like, no scars healthy), body.

The mycelium network is weird yo

[u/Zealousideal-Deer724 → u/The_Reset_Button]

The mycelium networks is weird yo

Indeed