Crossing the Spiral Arm

Over a journey of two thousand light-years, humanity had traveled for nearly three hundred years. At ten times the speed of light in warp, all the extra time had been spent replenishing supplies and energy.

After arriving at the so-called "Ferry Crossing," humanity, for safety's sake, deployed the Sky Survey Telescope Array and aimed every detector toward the Perseus Arm. They measured the stars along the route ahead one by one, then used the distances between each surveyed star to plot a course.

This route stretched for more than four thousand light-years. There were indeed many stars scattered between the two spiral arms, but they were exceptionally sparse—far sparser than anything humanity had previously called sparse. Take the two nearest stars in the direction of the Perseus Arm from the Great Fleet's current location: they were already one hundred and seventy light-years apart, and the farther ahead they went, the greater the distances between stars became.

Some stars were separated by distances that exceeded the limits of humanity's navigation technology.

So even though there were stars ahead, humanity had to survey every star between the two spiral arms in this direction to avoid walking into a dead end, then plan out as many Star Paths as possible.

Yet reality was far from ideal. After probing those stars one by one, humanity discovered that there was only one viable Star Path. The other routes either had stars too far apart or were outright dead ends, with nothing but empty void ahead and no stars at all.

What troubled humanity even more was that along this sole viable Star Path, there was a section where the distance between the nearest two stars exceeded five hundred light-years. Calculations placed it at roughly five hundred and fifty light-years.

That was already beyond the maximum