From "A Short History of Space Flight":

"You know, I trust, reader, that the stars lie at enormous distances, and that even light travels at a limited speed, taking years to cross the gulfs between them. For a long time this made interstellar communication meaningless, and voyages lasted far too long. The few colonies founded by humans lived each unto itself. So it went for centuries — until one day an engineer hit upon a way to accelerate a spacecraft beyond the speed of light. He mounted a gravity generator (the kind used to boost interstellar ships to near light speed and to maintain artificial gravity) on an orbital yacht and passed beyond the edge of the system. There he used the generator to create a distortion of space that allowed him to accelerate past light speed. And he succeeded. He made the crossing in about three weeks, against a usual duration of some 3 years. His speed came to about 52 times that of light (a transit at +52). He handed the plans to the colony he had reached, and went on, passing the precious knowledge to every human settlement. His priceless discovery overturned the world of his day and laid the foundations of our present civilization..."

From "Spatial Drives — A Survey of Types":

"Today many different methods are known for crossing space at superluminal speed — from the space-warping drive to the method of the Arian mediums.

I. Kilartian tunnel transit:

It uses a peculiar zone created by the interacting gravities of sufficiently large bodies (of the order of at least one thousandth of a stellar mass) — that is, stars. This zone is a region in which resistance to a body's entry into superluminal speeds is weakened several hundred to several tens of thousands of times. Something like a tunnel forms, reached at a distance of several light-days to several light-weeks from the center of the star or multiple group serving as the transit's start or end point. Speeds range from +10,000 (the lowest possible) to +10,000,000 (the highest yet measured). For the necessary region to exist, the stars must be in direct line of sight — that is, no other massive body (a star, a nebula) may stand between them. Far more efficient than the hyperdrive over great distances (above 100 light-years).

II. Hyperdrive:

Invented by the Bernardian Ernesto da Silva, it rests on the active warping of space, as against the use of the passive transit tunnels. At first only gravitational warping was used; later the hyperionic and pulse-phase types were discovered. Owing to the shortage of energy, no speeds above +5,792 have been reached — and even that order is attainable only by certain warships of the heavy class and by courier ships. Most drives in use run from +1,000 to +1,500..."

From "The Beginning Navigator's Handbook":

"On the naming of star systems and sectors

In the era before space flight, humanity had divided the sky visible from its home planet into parts called 'constellations.' Later it used some of those names for space sectors lying in the part of the sky, as seen from Earth, that corresponded to the constellation. The sector's boundaries were then fixed at no more than 59 light-years across. The objects falling within them were numbered, beginning from the point nearest Earth and proceeding outward.

In more recent times the tradition survives; only the sectors' outer boundaries have changed, growing more distant and larger. This forces their division into parts, and each sector so formed carries, besides its name, the numbers of its nearest and farthest objects from Earth. In this way regions of different sizes are defined, and some stars of one may belong also to another..."

Shields down