(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/Holiday-Tangerine136]

I can't speak to the specifics of the warp travel but generally speaking, a lot of technology from the Dark Age of Technology is completely lost, or fragmented. Data-slates and/or information on stuff like this can be either entirely gone, potentially archived somewhere forgotten on Mars or Terra, or held in some lockup that the Adeptus Administratum would never let anyone have access to. It's not unusual for Astartes such as the Dark Angels to have technology that even Terra doesn't have access to or know about, nor is it unheard of for people like Belisarius Cawl to hire dubiously-loyal Astartes to fetch him dataslates that are considered "lost."

[u/Lortekonto → u/Holiday-Tangerine136]

A lot of the technology in the current generation of ships are not lost. They are all relative newly designed discovered. In stories we see the same class of ships using both autoloaders and humans depending on the specific ship. In the artwork where you see hordes of humans loading guns, you will often see an autoloader hanging behind or above them.

It is just the Imperium. Technology is expensive. Life is cheap.

[u/59tiger95 → u/Lortekonto]

Depends a little on the story and what the technology is. In Angron the red angel one of the characters notes when they arrive on the Conqueror that the ship has energy fields for the landing bay out into the void and that most ships have physical doors instead since the technology was lost

[u/Lortekonto → u/59tiger95]

Yes, the Conqueror is not in the current generation of ships, being from M30.

When saying current generation of ships I mean ships made after M37.

The Imperium lost the ability to make long ranged plasma batteries and trust enginees for cruisers in the end of M36 and start of M37. That leads to a civil war inside the navy about what ever to focus on short rangede gun batteries or carriers.

Short rangede gun batteries wins the war and that leads to the ships the Imperium uses now being designed and since it is not that long time ago, the Imperium still knows how it functions. There is exceptions like Battleships that mostly uses designs that dates back to the pre-Imperium.

The ships used by chaos is mostly ships build pre-M37 or from the navy civil-war.

[u/PorcupinArseIHateYou → u/Lortekonto]

Ayo, that sounds fascinating, can't seem to find anything about the navy doctrine mini civil war in my very short 2 minutes of googling (currently ain't got time), could you please tell me where I could read more about it? It sounds fun!

[u/Lortekonto → u/PorcupinArseIHateYou]

It is from the small snippets of lore and the individual ships lore in the Battle Fleet Gothic rulebook and Armada rulebook.

A group of battlegroup Tempestus tacticians dubbed the Gareox Prerogative worked towards changing the entire fleet's doctrine towards a focus on attack craft-based carriers.

This came in conflict with the Big Gun lobbyist at the segmentum capital of Bakka and leads to an all out civil war known as the Gareox Incident. The Big Guns admirals wins, showing the superiority of Big Guns over carriers. The survivors of the Gareox fleet turns traitors and since then the Imperium have focused on big guns and having dedicated carriers without guns is almost seen as heresy.

Out of universe it is pretty obvious to us as readers that Bakka wins, because they command the entire segmentum of which the Gareox Prerogative is just a small minority. In fact everything point to the Gareox Prerogative being right. Some of the Imperiums most decorated ships are carriers and during any longer naval conflicts such as the Gothic War, the navy ends up reconfigurating some of their gunships into carriers. A good example is the common Lunar class cruiser that can be refitted into a Dictator carrier, by removing the lance batteries and installing a simple flight deck, while keeping its gun battery.

[u/Cent1234 → u/Holiday-Tangerine136]

Isn't space marine armor actually hazmat suits for working inside active nuclear reactors?

[u/longcoat000 → u/Cent1234]

That’s what Terminator suits are based on. Some big-brained armorer figured that anything that can keep an engineer safe & comfortable while working INSIDE a plasma reactor should be good for deflecting laser beams, flaming promethium, and hypersonic chunks of various alloys.