Faster Than Light Drives and Communication in the Empire of Humanity

Drives:

Faster than light travel has turned out to be one of those things there are many solutions to.

Far and away the most common are Vector Drive and it's newer child, Interstitial Vector. These are essentially instantaneous over even inter-galactic distances (or between instances of creation as well in the case of Interstitial Vector). The drawback to both is computers on their own aren't accurate enough for reasonable accuracy - you need an operant pilot capable of handling multiple simultaneous equations over a short period of time immediately prior to a Vector. This means Vector pilots are expensive as such things go and many things flow from this fact, from the drive for ever larger ships to a need for insystem ship crews to maneuver before and after a Vector, and pilot modules that plug into those ships carrying a Vector pilot.

An alternative for shorter distances is a timejammer. Timejammers can handle speeds of up to about sixty cubed times the speed of light, and they do not require operant pilots. The issues are two: Unlike Vector Drive vessels, they actually must travel the distance involved and they have to be careful not to run into anything at those speeds. They also capture and build up a 'buffer' of photons that tend to attract the attention of anyone looking in the area - timejammers are definitely NOT 'stealth' ships. Even Earth's technology pre-contact had no difficulty picking out the one timejammer that was operated in the system before official contact. Timejammers tend to be smaller ships, run on shoestring budgets within a galactic neighborhood of sixty light-years or so.

Phase One space is a sort of hyperspace where faster speeds are possible sub-light. Very common with less technologically advanced races but only rarely used by Imperial vessels.as timejammers are faster, but it is easier to guard against collisions are you're not exceeding speed of light.

There are fourteen other known methods of faster than light travel, but the ones above are by far the most common.

Finally, it should be noted that modern impellers are capable of interstellar voyages sublight. This is a commonly taught means of recovering from a FTL failure away from civilization where it cannot be fixed for some reason: Crank up the impellers and head for the nearest Imperial system. It'll only take a week or so of subjective time, and if twenty years or so pass in the main universe, that's not an impossible adjustment.

Communications:

Tachyonic communications has a maximum range of about three years (just over two Earth Light-years). In First Galaxy of the Imperial Home Instance, there is a well-developed relay system that works to pass messages at tachyonic speeds all over the galaxy. There are less-developed systems in several other of the more heavily colonized galaxies of the Home Instance. However, bandwidth is limited and therefore it's often cheaper as well as faster to use Vector couriers as the military does.