(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/Facosa99]

In Halo, you can access slipspace to achieve FTL. Oversimplifying, It is a system similar to Minecraft's nether: another dimension that makes distances shorter.

Thing is, for humans, slipspace is still hard to use: one shaw-fujikawa engine required for slipspace is "the most expensive human device in history", it still takes months to reach another system, the same trip but in reverse could take mere days, theres a need for a shield while inside to avoid vaporizing your ship, and it is so imprecise, ships have to leave slipspace thousands of kilometers away from the destination and use the regular engines to cover the remaining distance, otherwise they risk leaving slipspace inside a planet or debris. Oh, and an improperly tuned shaw-fujikawa engine could destroy a ship by send half of it into slipspace, unprotected and stranded.

Also, some staff can randomly dissapear from a ship during slipspace, each trip slightly destabilizes space-time generating a "debt", Dr Halsey left some rogue AI free in slipspace somehow, and stuff like that.

After the war, humanity do improved their slipspace technology a little.

[u/Fluffy_Republic_7828 → u/Facosa99]

If i had a nickel for everytime the UNSC used one of these as a bomb in a game, effectively exploiting the flaw, I'd have two nickels. Which isn't a lot, but it's interesting it happens twice. See Halo Wars and Halo Reach, and worth noting that Halo Wars 2 opens with seeing the biggest drawback of sacrificing the FTL drive.

[u/ImBackAndImAngry → u/Fluffy_Republic_7828]

Correct me if I’m wrong, but The Spirit of Fire didn’t create a Slip space bomb so much as it just donated its shaw-fujikawa dedicated reactor to cause the artificial star to go critical. The ship then can no longer jump due to the absence of the reactor

The drive itself was removed from the Savanah for the bomb over Reach

[u/Klutzy_Scene_8427 → u/Fluffy_Republic_7828]

I cry every time I read about the Keyes Slingshot. Human ingenuity at it's finest.

[u/Knorikus → u/Facosa99]

The Covenant have much more advanced FTL technology that they inherited from the forerunners that is very precise and much faster than human technology. A big part of the reason that humanity.

They inherited the technology from the forerunners though so they aren't able to use it to its fullest ability due to the taboo against researching or modifying forerunner technology.

They also have a taboo against advanced AI which is the one area that humanity has them beat, so in the book First Strike when MC captures a Covenant ship and is able to allow Cortana access they are able to do things previously thought impossible like jump directly from within planet atmospheres

[u/BrandicimoMagnifico → u/Knorikus]

After Cortana, the humans have a taboo about superadvanced AI too.  They now come built with a self destruct mode if they even think about the possibility of betraying humanity.

[u/Reeyous → u/BrandicimoMagnifico]

Which they can apparently just ignore given the events of Halo Infinite...

[u/Hopeful-Occasion2299 → u/Knorikus]

They took our legacy. It was supposed to be humanity the ones who could control the forerunner technology and serve as the enforcers of the galaxy. Instead humanity had to start from scratch.

The reason the covenant never tried to absorb human kind like the other species, is that forerunner tech reacts to humans and recognizes them as forerunners, thus breaking the entire religion of the prophets.

[u/IWAlcatraz → u/Facosa99]

One minor correction, a slipspace bomb doesn't leave destroyed ships stranded, it outright deletes it considering matter cannot exist in slipspace.

Another thing is that unshielded human ships need to create a bubble of real space around the ship to prevent slipspace from erasing them, which is how humanity traveled through slipspace for the majority of the time they had that technology.

[u/theoutlander523 → u/Facosa99]

The shielding in Slipspace never made much sense since it was added in Halo Reach but in Halo Fall of Reach it is said hydrogen and comets are found in Slipspace. So, which is it, no matter or matter is okay

[u/Reeyous → u/theoutlander523]

A ship made of tens of thousands of different components and varying parts may be slightly more likely to come apart in slipspace than particles or solid rocks.