It has been mentioned in certain places of the Background of the 4oK Universe that humanity sent out generation- and sleeperships before warp travel was discovered. Now, suppose such a ship were to appear in the Calexis sector, and the Players were sent out by their Inquisitor to investigate. What happens? What do they find?

I suppose it depends on how long ago the generation ship was sent out. One this is for certain, there would be a lot of technology aboard that could be of use to the Machine Cult, including the possibility of an STC.

Here are some ideas!

This ship is full of colonists still preserved in hypersleep. These colonists are genetically pure. That is, not only are they free of mutation, they were selected for this colonization attempt because they also lacked the genes for all known genetic disorders. They could be of incalculable worth to the Magos Biologis. They could also be useful in other ways, such as being transplanted onto a planet with a stagnating or limited gene pool. The question becomes, will anyone be able to identify them as such, and what happens if a genetic comparison between these ancient humans and modern humans shows significant deviation?

Since the crew of the ship has been frozen for millennia the vessel has been maintained by a legion of robots under the command of a sophisticated AI. This AI could be malfunctioning or insane, or could be doing exactly what it war programmed to do. Either way, the robots will attempt to protect the colonists from harm.

Or,,,

The ship could have already been infiltrated by an alien threat, such as Dominators or Genestealers. Each frozen colonist has been compromised, each one a slumbering threat to the Imperium. The presence of the acolytes could trigger the revival of some of the colonists, who them prepare to revive the rest of the crew and plan the invasion of the nearest Imperial world.

Or...

It just occurred to me that the title of the post to which I am replying regards Generation Ships.

The ship is a generation ship, full of mutants. Perhaps they were mutant rebels from a pre-Imperial age seeking a world of their own, or mutants from a dying hive world lost to the Empire trying to find a new world on which to thrive. Either way, they have much salvaged technology about their ship, and will be looking for a suitably low tech world they make colonize, sure of limited resistance of low-tech humanoids.

Or...

The acolytes may have discovered the base of operations of a lost order of Space Marines. Imagine if you will a chapter or Space Marines. Sometime during the Horus Heresy their Primarch comes to the conclusion that the corruptive potential of the Warp is so great that it's better not to dabble in the Immaterium in any way, even if that means abstaining from FTL travel. Gathering his Chapter, a cadre of faithful early Imperial citizens, and a circle of Tech Priests interested in such an endeavor, he constructs a massive generation starship and swears an oath to strike at the very heart of Chaos and Horus the Traitor. He points the generation ship towards The Eye of Terror, and has spend the last several millennia training generation after generation of Space Marines uplifted from the hearty citizenry of the ship, then keeping them in stasis waiting for the day the ship arrives at The Eye and they may defeat the forces of Chaos and The Traitor with their purity, faith, and stockpile of original pattern bolt guns.

This puts the Acolytes in a difficult position. Any number of things going on aboard the ship could be considered heresy, especially since the citizens of the ship are descended from people of a pre-Imperial Creed and pre-Ecclesiarchy era. No one aboard the ship knows anything about Imperial history since it embarked on it's mission. They likely think The Emperor is still alive, and will be inclined to think Horus is as well. On the other hand, the Primarch is a powerful being who has actually stood in the presence of the living Emperor, who has conversed with the living Emperor, and who knows lore that would be invaluable to the Inquisition and Ecclesiarchy, provided it doesn't jive too much current orthodoxy.

Ever heard of Digga Nob? It was an expansion for Gorkamorka about humans who had gone feral and based their culture on the successful culture of the Orks that dominated their planet. Imagine a world where that happened, and the humans manages to salvage enough technology to build their own 'ulk and take off for a Whaaaahg! That could be the origin of the generation ship, a cobbled together mass of fusion engines, life support pods, and force shields all studding the surface of a hollowed out asteroid. Their mad Ork inspired priests are just waiting to land on a planet and lead their boyz to a good right. The humans paint their skin green, have half-human half-ork names (like Erasmus Gazgah or Zkullbash Thatcher), and used cobbled together technology that is clearly of human origin yet mangled in suitably orky ways. There may or may not be a Madboy at the hearth of all this, or there may be a pair of ork Warboss skeletons the humans worship as idols of Gork and Mork.

Infernal Teddy said:

There are... things... out in the dark between the stars. This leads to all kinds of possible horror stories. They find row upon row of cryo-suspended humans, but when they unfreeze them they realise (too late) that they've been possessed by a xenos intelligence that turns them into ruthless, highly intelligent cannibals. Or they find no humans on the ship at all... but an invisible presence stalks the corridors of the ship, an intangible horror that strips the flesh from mens bones. Maybe the ship is run by a DAoT AI that has gone mad during the millenia in space.

In my game there are deep void clans.

Deep Voiders, and Long Voiders are clannish spacefarers generally lacking warrants of trade or other imperial authorization. Cybernetics, and warp mutations are prevalent among Deep Voider crews. Long Voiders rightly fear the dangers of warp travel, and the possibility of mutation.(Cybernetics are very common /w long voiders.) Instead using gravic drives to accelerate to relativistic speed for the long haul across real space. Both groups prefer to do their business in deep space rather Imperial controlled systems. (A specialize subgroup of Long Voiders specialized in trade with system occluded by warp storms. They will use warp travel to reach the edge of a warp storm.) Long voiders, and to a lesser degree deep voiders make extensive use of cold sleep.

The Inquisition come across a hulk and the Acolytes are sent aboard to investigate. What they find is generation ship containing an idealized and pastoral human society with little violence or disease. The people are ignorant of the Imperial Creed and much of galactic history, but they don't show any signs that they couldn't be educated into the Faith and made part of Imperial society. But it is also clear that they know little of technology and there is no way they could be maintaining the starship. And then a whistle blows and a large chuck of the population walk through massive bulkhead doors and are never seen or heard from again. As it turns out, hundreds or thousands of years ago a race of Xenos came aboard the ship. Perhaps they took over, perhaps they were invited. Either way, they soon came to dominate the command and engineering decks of the ship and turn the habitat levels into giant free range human farms. They feed upon the humans like the Morlocks feed on the Eloi, and the humans don't seem to mind. It's become natural for them. And you can plug in your favorite Xeno. Could be Orks who know a good supply of fresh meat when they see it, or it could be a sect of Dark Eldar who have found the flesh of the Mon-Keigh to be a delicacy. Or it could be something as horrible as your imagination can spawn.

The scenario doesn't necessarily even need to be a combat or horror based one.

Pre or early Imperium humans would have vastly different beliefs (for example in the Horus Heresy books the early Imperium was a hardline secular state).

The leader of the colonisists is a man of vision and charisma. He comes from a genetically pure stock and was trained to organise worlds. He would be of great benefit to the Adeptus Terra who normally have to deal with self serving and often corrupt governors.

Maybe the acolytes need to interrogate and assess whether the leader of the colonists could be intergrated into the Imperium. Or does he harbour ancient beliefs which are inherently heretical and must be shot out of hand.

Generation ships are a pretty cool sci-fi idea, but if they're pre-Imperium, pre Age of Technology, we're talking 25K years old. Still, in a big enough galaxy, why not?

Well if they do come from the Dark age of Technology, then any one of them may be more technologically advanced and knowledgeable than your parties Tech Priest. The entire Sectors Mechanicum would probably turn up demanding exclusive access and control of these heretical technologicalists on pain of immediate cessation of anti-agathics and enginseering services to the Inquistion.

The Magos would want to know everything the colonists know about tech (especially if they have STC's) while re-educating these atheists in the proper belief in the Omnissiah.

SJE

DifferenceEngine said:

Real science provides us with a way to reduce how much time has passed for the ship. All we need is for the ship to have travelled at a high fraction of the speed of light*. Then relativistic time dilation would have slowed down the passage of time aboard the ship. This can be calculated with SQRT(1-v^2/c^2) where v is the velocity of the ship, c is the speed of light and SQRT() is the square root of the number inside the brackets.

At half the speed of light (0.5c) time inside the ship is only 86% of the time outside it. At 0.9c the time inside the ship is only 43% of the time outside. 0.99c and it's only 14% inside. Though that is ignoring the time it took to accelerate to that velocity.

*Which it probably has once you answer these questions:

How much years has the ship been travelling for according to someone outside the ship ?

How many light years has it travelled ?

One could find a ship populated entirely by robots. They were programmed to oversee the colonists in hypersleep, but over the millennia the frozen colonists have expired. The robots were programmed to let colonists out to breed in order to maintain a certain population for the intended colony. One could go in two direction.

The robots could be treating the humans like livestock, breeding them up to a certain number, then freezing them and stocking them in the hypersleep deck for later use, or they robots may have taken to "recruiting" other colonists from nearby worlds. Some chambers could be stocked with humans from across the Imperium.

How about an early 'hybrid' vessel- part Orion drive, part Bussard ramjet? Uses the Orion drive to attain sufficient velocity for the ramjet to function, and then it can accelerate for an infinitesimal (or smaller) fuel cost. The downside is that it won't be able to slow down, and will be scooting across the Calixis sector at an appreciable fraction of c . It may even have the original (or at lest 2nd-3rd generation) colonists aboard. For added fun, have it on a collision course with an inhabited planet (say... Sepheris Secundis), and have the acolytes boarding in a countdown to divert or destroy it. Don't forget that once they match velocity with it, that "3 years till impact" will be closer to "a matter of hours" (for them) before the Navy blows it up with a well-placed torpedo salvo...