Generation Ships: All you need to know

I posted some musings on Generation Ships in a thread in the main forum, and popular demand (well, OK, it was DNA-Decay, but I'm sure he's quite popular in some parts) requested I post the information in the Lore subforum, so it didn't get lost. Rather than simply duplicate it, I'll reformat it, and add some further musings too. I'll do it in the form of a FAQ.

What exactly are generation ships?
Generation ships are gigantic starships which were launched in the early years of interstellar travel to colonize other star systems. The name "generation ship" implies that the voyage was intended to last for multiple generations. It took so long, because these ships travelled at sublight speeds - meaning it took many decades to travel from Sol to the destination star. A starship that intended to arrive at its destination in less than a generation is merely a "colony ship", rather than a "generation ship". Later colony ships equipped with faster-than-light hyperdrives are also not usually called "generation ships", even if their voyage did take over a generation.

When were generation ships launched?
The first generation ship, the Mayflower 97, was launched in 2097, bound for Tau Ceti. The last generation ships had launched by 2700; improvements in hyperdrive technology meant that generation ships had become obsolete technology. I assume that production started out very slowly, then gradually sped up over time, then tailing off quite quickly once hyperdrive-equipped colony ships took over the role. On that basis, I would assume that peak production occurred in the period 2500-2600. This means that any generation ship still intact has been in space for at least 600 years, probably more in the 700 to 1000 year range.

How many generation ships were launched?
The official answer is "about 70,000". Personally, I find this number difficult to accept (for reasons outlined below), but both Drew Wagar and the devs in FD have quoted this number, so I suppose it must be accepted as canon. If production peaked in the 26th century, then I would estimate that about 50,000 starships would have been launched in that 100-year period. That's an average of 1.36 launches per day. The industrial output required to build, fit out and launch so many giant starships must have been prodigious.

Which star systems were generation ships aiming for?
Their destinations would have been star systems within a couple of hundred LYs of Sol. All generation ships were launched from Sol; the colony worlds would have all been too small in both population and industry to undertake construction of a new generation ship. The destination systems would most likely have contained worlds which were either already Earthlike, or fairly easily terraformable. But here we have a problem: there aren't 70,000 natural-Earth-like and terraformable worlds within the Bubble. Even with a ridiculously high 50% loss rate, there's just not enough planets for that many ships. So, many of the ships would have had to have "doubled up", with two or more ships being sent to several of the planets.

What was supposed to happen when a generation ship Arrived?
The Arrival of a generation ship would have been the biggest event in a colony's early history. It was Arrival with a capital "A". Generation ships brought not only the breeding stock for a viably large human population, but vital resources for a colony: detachable habitats for the colonists, a nuclear powerplant for energy, all the supplies, medical gear and scientific equipment a new colony could possibly require in order to tame their new world as quickly as possible. Parts of the ship would no doubt have been kept in orbit, forming the nucleus of the planet's first space station. Most of those early stations have now of course been rendered obsolete and de-orbited.

How fast did generation ships travel?
A generation ship travelled at a small fraction of lightspeed; none are known to have travelled so fast that relativistic effects for the passengers and crew would have been significant. The Mayflower 97 took 58 years to travel the 11.97 LYs to Tau Ceti, giving an average speed of 0.2 c. There's only a couple of other indicators of ship speed in the currently known logs: the Thetis seems to have travelled 53.56 LYs in "nine generations"; if we assume that's about 300 years, it would give an average speed of 0.17 c. The Demeter was in space for at least 537 years and is 96 LY away, which would also give a speed of 0.17 c (though it may have stopped at its current location some time before the final log entry). It seems 0.2 c might be a typical speed for a generation ship, no matter what the tech level.

There is some evidence that at least some ships were built to travel faster, and it is reasonable to assume a ship aiming for a more remote destination might attempt a faster passage. The most remote known generation ship, the Phobos, is currently 272 LYs from Sol and would have needed an impossibly long 1360 years just to reach that location travelling at 0.2 c (by "impossibly long", I mean that if it had arrived there in 3304, it would have had to have been launched in 1944!). Given the nature of the incident that caused that ship to be abandoned, it seems likely to me that the actual colony which that ship had attempted to found was even further away from Sol and the survivors were attempting to flee back into inhabited space when they perished. Assuming a travel distance of about 300 LY, the Phobos must have been travelling at something closer to 0.5 c to reach its destination in the roughly 600 year window.

How long was a typical generation ship voyage, and how far away were their destinations?
The Thetis log implies that the 300 year long voyage up to the time of the tragedy was neither unexpected not abnormal. We don't know how far away the maximum destination would have been, but I find it difficult to believe that the voyage plans extended more than 500 years. 300 years at 0.2 c would take you 60 LYs, and there's plenty of real estate in a 60 LY radius of Sol. 500 years would take you 100 LYs, halfway to the edge of the current Bubble. But if generation ships were really departing multiple times a week at their peak, why would anyone sign up for a 500 year or longer voyage when shorter ones were available? It would have to be a dedicated get-away-from-it-all cult to volunteer for such an extended voyage for themselves and their descendants. But it does mean that all of the generation ships should still be inside the Bubble; a 1000 year voyage would only just now be reaching the edge of the Bubble. This also means that there are no far-remote "missing ships" or "lost colonies" founded by generation ships; any "lost colonies" in deep space beyond the Bubble (such as the Discworlder colony in HIP 74290) must have been founded by a hyperdrive-capable colony ship instead.

How much did the colonists know about their destination planet before they left?
A great deal, it would seem. As far back as the 21st century, Earth-bound planet-hunting technology was surprisingly good at detecting planets in certain circumstances; this technology had certainly improved by the time the first ships launched. In addition, in most cases, unmanned probes and bold explorers flying dangerously unreliable early hyperdrive starships would have already explored the system prior to launch. It seems likely that the organization funding the ship would have a prospectus made, lauding the positive attributes of their particular star system. Very few ships would have been launched on a "Hail Mary" flight schedule, with neither passengers nor crew having any idea about their destination, although the Spear of Hope seems to have relied on its own fleet of probes as they searched for a suitable world.

The downside to this, for some generation ship passengers at least, was that "their" planet would most likely not be completely empty when they Arrived. Most successful Arrivals would have been greeted by a fleet of hyperdrive ships. Some, no doubt, may have Arrived only to find that other people (either earlier generation ships or later hyperdrive colonists) had already founded a thriving, viable colony there. The ship would have had to decide whether to try to assimilate into the local colony, or press on looking for an emptier planet.

The Phanes logs prove that information about the target planet was not always accurate, either by omission or by deception. In the case of that ship, it was not rigged for terraforming or colonizing a non-ELW and their original destination (now unknown) was found to be uninhabitable upon arrival.

Why would colonists have boarded a generation ship, rather than take the much faster hyperdrive ships?
Hyperdrive theory was discovered shortly after the first generation ship launched; the first unmanned probes and primitive manned scout ships were launched a few decades later. However, these ships were (a) not all that much faster than generation ships - the trip to Alpha Centauri would have taken months, rather than years - and (b) they were small, cramped and dangerous - not the sort of contraption you'd want to trust your family on. Space travel was risky, but hyperspace was even riskier. Furthermore, as noted above, a generation ship was a ready-to-assemble colony upon Arrival; a hyperdrive survey ship had no capacity to carry the equipment a colonist would have required.

Why would so many colonists have wanted to leave Earth, anyway?
Contrary to popular belief, it was not overpopulation on a crowded Earth that drove people onto the generation ships. Each ship held about 10,000 to 20,000 people, though some may have been launched with a smaller complement, giving space for an expanding population (the Demeter had a crew of only 3000 just five years after launch); this means "only" a billion people boarded generation ships, which would not have made an appreciable difference to a crowded, overpopulated planet. The real reason was quite the opposite, actually, because the Earth these colonists left behind was not overcrowded, but rather depleted.

It is difficult for a 34th century galactic citizen to understand what life on 22nd century Earth was like. In the mid-21st century, Earth was devastated by World War III, during which the most horrifying weapons ever devised were unleashed throughout the world upon the civilian populations: nuclear weapons, primitive laser weaponry, autonomous killing robots, and worst of all, genetically engineered biological weapons. The population was decimated, but ironically, much of Earth's industrial infrastructure was still intact. Further, large swathes of Earth were rendered uninhabitable for the survivors. Reconstruction took several centuries before Earth was brought back to pre-war environment and population conditions. In the meantime, there was nowhere else to go: no interstellar colonies had yet been founded, and Mars stubbornly resisted early terraforming efforts. The various peoples of Earth realised that they had narrowly avoided extinction. A generation ship offered a way for entire nations, ethnic groups, ideologies and religious movements to ensure their survival.

Were all colonized worlds in the Bubble founded by generation ship?
No. A few were founded by hyperdrive colony ships, before any generation ship could have Arrived. Most famously, the founders of the Achernar colony set sail in primitive hyperdrive colony ships in the late 2200s, risking their families during years of hyperdrive travel in order to found a new society far away from the ever-tightening bonds of the Federation. And the systems on the outer fringes of the bubble are much more recent than the older systems closer to Sol.

Why did all the generation ships "go missing"? Didn't they have radios?
While some more secretive cults and groups no doubt wanted to disappear from the galaxy, most generation ships would not have wanted to be forgotten completely. I suspect the reasons lie partly in economics, and in motivating recruitment for further launches. People would not remember fifty, a hundred, a thousand successful launches, they would remember the one or two failures, the ships dying in the cold vacuum of space, far from any possible rescue. Losing contact would mean the starship companies could honestly claim "none of our spaceships has ever been known to fail". Some ships were certainly built shoddily and cheaply; the logs of the Lazarus complain about theirs being a base-model ship. Those ships were the Third Millennium equivalent of the 19th century "Coffin Ships" of old Earth oceangoing history: the ship companies made all their profits prior to launch; once launched, there was no economic motive for the company to "stay in touch". On the part of the generation ships themselves, they had no way to force anybody back on Earth to listen to them, and once the first generation died out and nobody on board knew anybody back on Earth and vice versa, there would have been no reason to even try to maintain any contact.

All the generation ships discovered in recent years have been dead hulks. Are there any "live" generation ships still around?
This is tricky. By definition, we can't know for sure, since they're "missing". However, it does seem to be true that no colony ship has Arrived unexpectedly at some far-flung world any time in the past hundred years. An Arrival is big news, not something that happens on the quiet. If generation ships are still out there, with colonists on them, then they're the tail end, the extremely long voyagers. I would expect there to be no more than half a dozen that are still on course, and maybe up to another dozen which have had some kind of disaster or mission failure but still have survivors on board.

Several hundred years ago, laws were introduced in all major galactic jurisdictions that interfering with a (live) generation ship was a capital offence. It is possible that the authorities of the time had gotten wind of the Venusian Incident or something similar. They are to be left alone, and left to make up their own minds whether to continue their voyage and whether or not to complete their Arrival. As far as we know, such laws are still in place, even though there are no publicly known generation ships to apply the law to.

There could, of course, be knowledge of such ships, kept in secret. There are two pieces of evidence that this may in fact be the case.

First, there are several permit-locked systems scattered about known space, some quite close to the fringe of the Bubble, for which the permits are unobtainable. It seems reasonable to me that, if the Powers That Be wished to protect a generation ship that was about to Arrive, slapping a permit on the system might be a good way to protect them from outside interference.

Second, there are at least 25 perfectly good Earth-like planets within the Bubble that nobody has colonized yet. TRAPPIST-1, of course, but there are plenty of others. We must have known of the existence of these worlds for centuries. Why would they still be empty, unless people in authority were protecting those planets, "reserving" them for future colonists? And might those colonists be known to be enroute aboard a generation ship? There is one case that may give evidence for this: an uninhabited ELW "only" 145.56 LYs from Sol (HIP 114458) which is currently orbited by a dead generation ship, the Achlys. Assuming a speed of 0.2 c, it would have taken 727 years for the Achlys to Arrive; assuming it left some time around 2500, it seems likely that the Achlys has only just recently Arrived at it's destination, some time in the last fifty years. Perhaps that planet was being "reserved" for the Achlys colonists, who sadly did not survive the journey.

So, where are the known generation ships right now?
The Canonn Institute list is the best-maintained list at the moment. There are fifteen currently known as of the last edit to this post. The following is a quick summary of each one.

Location: HIP 114458 (145.51 LYs from Sol)
Mission status: failure. This is the only known instance where a ship Arrived properly, but without its passengers and crew. It is also the only known generation ship still currently orbiting its intended destination system, an Earth-like world which curiously remains uninhabited to this day.
Cause of mission failure: mechanical failure (catastrophic loss of life support systems resulting in death of all aboard).
Survivors: none detected.

Location: Mu Cassiopeia (39.87 LYs from Sol)
Mission status: failure
Cause of mission failure: societal breakdown (takeover by murderous religious/philosophical cult)
Survivors: none recorded.

Location: Charick Drift (28.60 LYs from Sol)
Mission status: qualified success
Qualifications: mechanical failure causing loss of main propulsion; unable to properly Arrive. Ship evacuated by lifeboats in attempt to complete mission.
Survivors: most of crew evacuated successfully. It is not certain which Earth-like planet the survivors evacuated to, but it appears to have been the original mission destination. It is logically not in the Charick Drift system, since the whole point of the evacuation was that the ship was unable to stop. It is presumably Solwards of Charick Drift, since a ship travelling at 0.2 c isn't going to be able to change course by much; the only system with ELWs even remotely between Charick Drift and Earth is Duamta. The other mystery, of course, is how a dead ship travelling at 0.2 c managed to stop itself and park in a stable orbit around a star.

Location: Mizuchi (95.68 LYs from Sol)
Mission status: failure
Cause of mission failure: mechanical failure 5 years into the voyage, causing loss of various systems: navigation, communications and habitat (food production).
Survivors: none. Ship's logs record societal breakdown following the mechanical failure: a descent into tribalism and cannibalism as the ship ran out of food.

Location: HR 2351 (194.04 LYs from Sol)
Mission status: failure
Cause of mission failure: unknown. Crew and passengers vanished, due to unknown cause; it seems unlikely the ship had Arrived at its current location, as there are no ELWs or terraformable planets in the system. Whatever happened to the ship left some automated sytems fully functioning.
Survivors: none known. Sole survivor of mysterious incident was prisoner in ship's brig, who did not know what had happened to the ship. Prisoner survived at least three years alone on ship but does not seem to have been rescued.

Location: Lalande 2966 (121.53 LYs from Sol)
Mission status: failure
Cause of mission failure: societal breakdown (takeover by suicidal religious cult)
Survivors: none.

Location: Virudnir (158.32 LYs from Sol)
Mission status: failure
Cause of mission failure: mechanical failure causing loss of both main propulsion and guidance thrusters. Ship cannibalized to manufacture lifeboats, some passengers reportedly evacuated to several different systems.
Survivors: only a fraction of passengers are able to fit onto the jury-rigged lifeboats. Unknown if or how many of these had made it to their selected destination systems. HIP 54692 is the only system currently with an ELW that is close to Virudnir, though it is unknown exactly where the ship was when the incident occurred; it may have been much closer to Sol.

Location: Alaunus (52.62 LYs from Sol)
Mission status: failure
Cause of mission failure: disease outbreak unable to be contained by medical personnel
Survivors: none.

Location: Ross 859 (165.98 LYs from Sol)
Mission status: failure
Cause of mission failure: societal breakdown (crew decide to no longer attempt Arrival but remain on board ship). It is uncertain which world the Odysseus was intended to arrive at; its present location seems unlikely as it is neither ELW nor terraformable. If the Odysseus kept travelling in more or less a straight line after deciding not to stop, then a system like BD-12 4699 seems a likely original mission destination.
Survivors: none. Some time after electing to not Arrive, the ship suffered a disease outbreak unable to be contained by medical personnel.

Location: Cephei Sector NX-U B2-0 (112.93 LYs from Sol)
Mission status: failure
Cause of mission failure: societal breakdown (civil war erupts on board after deception perpetrated by command crew is discovered). One can argue that the ultimate cause of mission failure was inaccurate information on their Arrival system because their target planet was uninhabitable. They were presumably not equipped to colonize an uninhabitable (non-Earthlike) planet. As a result, the command crew decided to lie to the passengers, telling them that the rest of humanity had become extinct and they could not "go back home" and must press on to find a new planet.
Survivors: none known. The final log entry was made while the civil war was continuing. It seems reasonable to assume that they killed themselves off to the point where their numbers fell below population sustainability and they died out within a couple of generations of the war. The planet the ship is currently orbiting (B 5) is an iceball, as are the rest of the planets in this uninhabited system, so it is unlikely anyone fled the ship at it's current location.

Location: Coelachi (272.03 LYs from Sol)
Mission status: short-term success, long-term failure
Cause of mission failure: after successful Arrival, hostile native non-sentient lifeforms on destination planet attacked and killed most of the colonists. It is uncertain which inimical world the Phobos had tried to colonize; Coelachi (the ship's present location) has a small mining colony on the fourth planet but the system contains no life-bearing planets at all, let alone a planet that might be suitable for a generation ship to colonize. One can extrapolate from the logs that the survivors had re-boarded the generation ship, fired up the engines and started it in motion towards another system (presumably somewhere they knew was already inhabited), before being killed off by one of the alien lifeforms that had stowed away on board the returning lander.
Survivors: none reported.

Location: Hez Ur (174.01 LYs from Sol)
Mission status: failure
Cause of mission failure: disease outbreak unable to be contained by medical personnel.
Survivors: possible. Although the disease was not fatal, it rendered the entire ship sterile, incapable of bearing female children. With no cure found by the time all the women were past childbearing age, the mission was unable to be completed. Some last-generation passengers apparently attempted to evacuate the ship; their destination and ultimate fate is unknown.

Spear of Hope
Location: HIP 21654 (151.57 LYs from Sol)
Mission Status: near-complete success
Qualifications: a single crewmember absent from the ship on an away mission was left behind, unable to join the rest of the crew due to lack of fuel for his ship. Crewman successfully steered ship to an alternative destination.
Survivors: entire crew (except 1) successfully Arrived at their chosen destination. Without many of the supplies from thier ship the colony may not have been long-term viable, but given the nature of its mission, the Spear of Hope may even have been designed to Arrive in this fashion. Fate of Crewman Farrow is unknown, as the current ship's location is in an uninhabited system containing gas giants with cold rocky/icy moons; his intended destination may have been yet another, unknown system.

Location: Nefertem (53.46 LYs from Sol)
Mission status: failure
Cause of mission failure: societal breakdown (mass psychosis, apparently induced by external interference)
Survivors: none.

Location: Kitae (63.12 LYs from Sol)
Mission status: failure
Cause of mission failure: external interference (attacked by slaver-pirates, betrayed by ship's XO)
Survivors: some passengers captured and enslaved; presumably dispersed through local slave markets. Remainder killed.
Last edited:
+Rep'd. It's friday afternoon, I've eated a huge curry for lunch, the sun in finally shining, and I now have a huge - but potentially interesting - wall of text to read.
Well written WOT! Thank you for sharing :D

A couple of points:
  • "Doubling up" ships to the same destination would actually have been sensible for anyone serious about founding a colony, because there'd be more chance of a ship arriving.
  • I feel like your dates for production a later than they should be, certainly the peak. Just looking at the timeline on Wikia (I know, not lore, but based on in-game references) it seems like most colonisation was actually before 2500.
Awesome summary! Thanks mate!
This is of great help for someone planning to make a tour of the generation ships after accidentally stumbling upon the Atlas [big grin]
It seems the directions for the Pleione are either incorrect or the ship is no longer there. I've spent some time searching but the ship is nowhere to be found.
I suspect what's happened here is the ship is still exactly where it's always been, but the planet Hez Ur 5 has moved around in its orbit, so the planet, the ship and the Teuten system no longer line up in a straight line.

Ideally, navigational directions for deep-space objects should be reported from the central star, or from immobile objects around the star (such as a nav or tourist beacon).
It seems the directions for the Pleione are either incorrect or the ship is no longer there. I've spent some time searching but the ship is nowhere to be found.
Can confirm I can't find the Pleione.

As Sapyx said, I'm going to assume the ship is in the same place but the moving point of reference moved and is no longer valid as a point of reference.
Can confirm I can't find the Pleione.

As Sapyx said, I'm going to assume the ship is in the same place but the moving point of reference moved and is no longer valid as a point of reference.
I noticed another post regarding these three temporarily "lost" ships and decided to find out if someone had found new reference systems for their discovery. It took a while, but found some very recent posts and headed out after the original instructions had failed me.
The listening post messages these ships were originally found from, reference planets in said systems and it's been a ~year, so that was probably a bit of an oversight from FDev.Someone might come up with longer lasting reference systems, if they're managing a database of POIs. These use the main stars as point of origin:

Generation Ship Hyperion - Lalande 2966 - Target Lyncis Sector EL-Y C8 and supercruise for ~8,500 ls. As per usual, it'll pop up in you nav panel within 1000ls.
Generation Ship Lycaon - Alaunus - Target COL 285 Sector RP-L B22-7 and go for ~30,000 ls.
Generation Ship Pleione - Hez Ur - Target Teuten, go 9,000 ls, stop, then head slowly towards Njana (maybe 2-5k ls, was too late I didn't pay attention to distance).


Thetis' story seems a bit unnerving. Rattles the imagination. Wonder what caused the psychosis..."external interference" ....qeue the creepy horror music.
...and apparently I haven't been paying attention, as there are two more generation ships listed on the Canonn website I haven't added yet. Will get around to doing that tonight.
OK, added the other two missing generation ships to the list. For those who (like me) were not paying attention, the three new additions are the Achlys, Phanes and Phobos.
OK, added the other two missing generation ships to the list. For those who (like me) were not paying attention, the three new additions are the Achlys, Phanes and Phobos.
awesome. I like reading about these. Hopefully one day, I'll be brave enough to venture out to see them. 😆
Top Bottom