“Finally, let us turn to the biggest megaships of them all, the fleet carriers. Including them in this work is a choice which I expect to be somewhat controversial – many would argue that a fleet carrier is a formation, not a vessel – but with respect to those readers who may hold that position, since the Imperial Navy treats fleet carriers as a single vessel for asset accounting and command designation purposes, so in turn shall I.

“Let us begin with a look at the history of the type. Fleet carriers were not known before the Exterminomachy (5782-5901). While before that time lighthuggers had met with occasional hostility, they had proven more than capable of defending themselves against local system defense forces, in particular with the Perreinar Wheel1 – and in those cases where they were not, it was because they had encountered a Power not readily opposed by pure military force. This changed with the arrival of the skrandar berserker probes, whose numbers and willingness to embrace suicide tactics made them a serious threat to even well-defended vessels, and eliminating breeding site for which required the transport of full task forces to their host systems.

“The first fleet carriers, then, were improvisations; lighthuggers pressed into service under the right of angary. Stripped down by removing all cargo capacity, much crew space, and all other less-than-essential facilities, and enhancing their fuel capacity with multiple drop tanks, it became possible to clamp a small number of light units – overstocked with fuel and supplies – to the spine of such a vessel, and have it haul them slowly and painfully to a target system.

“Such crude improvisations were fraught with problems, from wear and tear on ships and crew during the slow transit, to the risk of interception before the transported units could free themselves from the carrier – both due to the inefficiency of the mechanical clamps, and the need to cut clamps frozen in transit or actual hard welds used where clamps would not suffice, to even entire vessels lost from the carrier in transit. (The last of these to be recovered, CS Bloodwashed3, was salvaged with all hands in 6722.)

“Fortunately, by the third year of the Exterminomachy, new designs were emerging from the cageworks at Ashen Planitia and Armory. The second-generation fleet carriers were custom-built starships, or rather, the specialized elements (the “propulsion head” and “collier module”) were, since the second generation eschewed the rigid designs of the first in exchange for dispersed tensegrity structures.

“In effect, the starships transported by the fleet carrier, along with the specialized elements, formed the floating compression struts of the overall structure, while being linked by braided cables (derived from orbital elevator technology) into a unified structure. The majority of the propulsive thrust is provided by the dedicated propulsion heads, while specialized fleet mediator software enables the use of the drives of the various carried ships to balance the structure and correct attitude. Meanwhile, supplies carried in the collier modules, distributed by rigged flexpipe and by cable-crawling logistics robots, eliminated the need to overload any individual ship with supplies, and indeed enabled the transportation of greater volumes of fuel and replenishment. Moreover, such fleet carriers could separate instantly if intercepted by simply blowing the explosive cable-couplers and engaging their drives independently, the dispersed tensegrity structure providing adequate safety separation for this.

“Such dispersed-design fleet carriers served with distinction throughout the remainder of the Exterminomachy, and have remained a key element of IN subluminal doctrine since. While there exist a third generation of fleet carrier designs, these merely reflect the evolution in technological reliability that allows the physical cables of the second generation to be replaced with vector-control tractor-pressor beams, and does not reflect any change in fundamental design or doctrine.

“As ad hoc structures, of course, it would be incorrect to say that fleet carriers have classes, in the strictest sense. However, the individual propulsion heads and collier modules, the former full starships in themselves, do. Thus, we shall begin our examination of fleet carriers with a look at the most common propulsion head in Imperial service, the Legends-class…”

– Megaships of the Imperium, Lorvis Maric, pub. 7290

  1. Perreinar2 Wheel: a fight-and-flight maneuver in which a lighthugger puts its stern towards the battle and engages its interstellar drive, thus retreating from the engagement while simultaneously treating the enemy to the close-range efflux of a pion drive – a situation which is very rarely survivable for anything larger than a baryon.
  2. From the eponymous horse archers who had perfected the “Perreinar shot” centuries before.
  3. Lost in the wreck of CS Cúlíän Daphnotarthius, which suffered a structural collapse of the spine while outward bound to IGS 31238 in the second year of the war.


functional lightspeed (n.): A curious quirk of relativistics; thanks to time dilation and distance foreshortening, when a lighthugger on a sufficiently lengthy voyage achieves 0.707 lights, the wall-clock time experienced by the crew exactly matches the length of the voyage in the empire-time frame, thus creating the mathematical illusion that the starship is travelling at the speed of light.

While meaningless in practical terms, this has not stopped lighthugger crewers from using it as an excuse to throw a party and hold a “light-barrier crossing ceremony” to initiate those who have never done so before into the Right Honorable and Inebriated Order of the Improbably Celeritous. Such ceremonies include initiation into the “mysteries of the deep black” by the gods of space and stars and their court (played by the oldest Improbables aboard), much drunken horseplay, and the traditional final rite of standing on the foreshield of the lighthugger until one’s nerve cracks, followed by the equally traditional treatment for radiation exposure.

– A Star Traveler’s Dictionary

Trope-a-Day: Year Outside, Hour Inside

Year Outside, Hour Inside: Thanks to relativity, truth in television for lighthugger crews, who slowly build up a hefty time differential (and cultural delta) with the parts of the universe operating on the empire-time frame.

(Hint: if there’s a family member or social grouping you just can’t live without, make sure you all sign up together.

…also, give up on playing MMOs or multiplayer games with anyone off the ship, no matter how much tangle you brought. Timeslip is much worse than netlag.)

Trope-a-Day: You Can’t Go Home Again

You Cant Go Home Again: A consequence of lighthugger travel and the ensuing time dilation for ephemerals; or people from ephemeral societies, rather, since its the high cultural delta of the society you left that causes the problem.

Also, more rarely, what happens to people left off-world at the time of an Apocalypse How or Gone Horribly Right.

Trope-a-Day: Subspace Ansible

Subspace Ansible: The tangle channel, which involves manufactured entangled (not in the standard quantum sense, note, because we know that doesn’t work; these are ontotechnological devices using the “privileged channels” a long way behind those) particle-pairs.  This makes them quite expensive (since they are a consumable resource, one particle per bit transmitted, and have to be shipped there the long way once you separate the ends; if you don’t have one or a stargate, your best option is a lighthugging communications torpedo) at least relative to using light-speed EM communications and relaying them through the stargates, the way most of the non-priority extranet works, but they’re invaluable for priority communications and beyond the reach of the stargate plexus.  (They are, for example, the only means of ready communication available to lighthuggers.)  And yes, they do work for mindcasting.

(And, yes, they can also let you play interesting games with causality. Just as expected.)

That said, extensive use of caching, prefetching, and AI traffic prognostication makes the extranet delays mostly invisible in practice, as does the ability to engage in pseudo-real-time communication by sending a partial copy of you along with, or as, your message to be able to have a real discussion with the recipient, then reabsorb it when it returns.

Trope-a-Day: Streaming Stars

Streaming Stars: Averted.  However incomprehensible the speeds lighthuggers move at, they’re not nearly fast enough – and can’t be, courtesy of the luminal limit – to create noticeable motion parallax.  Some blue- and red-shifting and relativistic distortion, yes, once they’re cruising along at the full 0.9c; but no motion parallax.


Xxenognosis (n.): (also “the Big Hello”) The knowledge that sophont species other than one’s own exist; also, the discovery by an individual or species that they exist.

In popular mythology, this is usually conflated with first contact, or at least with the establishment of genuine communications between the species in question – which portrayal, unfortunately, is almost pure nonsense.

Interstellar civilization just isn’t that subtle.

Space is cold and dark. Interstellar life is the exact opposite. Between the EM penumbra, starship drive flares, the gravity-wave ripples of stargates in operation, and even some few modified stellar spectra, anyone within a couple of thousand light-orbits of the Periphery with any astronomical competence at all can have no doubt that there’s exotic life out there – with the only possible exception being those on the wrong side of the Shadow Veil.

If you’re actually trying to make contact, you can’t avoid giving advance notice. In the first first contact on record, the galari identified Extropy Rising – a slowship, not even a lighthugger – light-months out of their system, even before the inbound ship spotted the radio emissions of galari civilization. The deceleration burn of a modern lighthugger is easily visible from the next star over, and highly distinctive to boot; an optimized fusion torch or the double-peaked signature of a pion drive look like nothing else in space. As for starwisps – how many stars do you think there are that shine monochromatic green?

(And if the lighthugger in question is a linelayer, it’s going to leave a stargate megastructure orbiting in their outer system for them to look at for months, maybe even years, before a scoutship gets there. Conveniently engraved with instructions for use, even.)

This does have its disadvantages, triggering social unrest, cultural shifts, bursts of technological development, and the like, or on less developed worlds – the kind whose occupants may go unnoticed until your arrival – sometimes even religious movements. In the case of psychotics-in-waiting like the skrandar, it may well have converted them into the berserkers they ended as.

But if you want to explore the galaxy at all – well, what can you do? Even the Voniensa Republic, who are remarkably prissy about this sort of thing, have had to reconcile themselves to that.

– A Star Traveler’s Dictionary