SPACE MERCHANTILISM
- "Supreme Chancellor, delegates of the Senate, a tragedy has occurred, which started right here with the taxation of trade routes, and has now engulfed our entire planet in the oppression of the Trade Federation!"
- ―Sheev Palpatine
Space is complicated, there's radiation, spaceship design, space pirates, distant colonies, and of course, the economy of galactic empires, but among these all, one in particular comes to mind when your story depicts space travel as a regular part of the universe, TRADE ROUTES...
Routes will eventually be cited, as a small part or as critical turning point of the lore (like the quote in the beginning of this post).
One may argue that space being 3D, and not having any particular preference by up or down, or left and right, space ships can just turn wherever they want and go in whatever direction they want, which is true - to a certain point.
See, we do launch rockets from sites near the planet's equator, Florida for the US, French Guiana for the Europe, Kazakhstan for the ex-USSR, Sriharikota for India - we do that, because when a rocket goes off the planet, it carries the rotational velocity of the launch latitude, the further away from the equator, less velocity, and the closer, more velocity, this increase in initial launch determines how much fuel and how powerful of a engine a rocket needs to carry, the further away a spacecraft needs to get, say like - Mars - the more fuel saving it will need to make in order to maneuver properly in it's way to the red planet.
Having that in mind, is easy to look and see why most of our satellites lay in an equatorial or tropical orbit, and thus many have to be several thousand kilometers away to attend northern and southern landmasses, as well, the planets and other solar system bodies do orbit around and rotate along the plane we call the Ecliptic plane (except Uranus), as everything or almost everything that might be of interest in a star system, is located within the ecliptic plane, it makes even more sense to launch spacecraft along this plane.
Now, the Ecliptic plane is not an universal plane of reference, not all star systems do have a similar alignment to our system, in fact, is almost counter-intuitive that despite all stars orbit in the same galactic plane - they aren't rotating in the same general inclination like the solar system planets do, they rotate in scattered different directions, and thus, this mean, that despite the closest star to a said system is 5ly away, the closest outpost may be 8ly.
This also mean that a galactic empire may start or be for a long time - limited to the systems in it's core system's ecliptic plane.
Which is a rather interesting idea, to populate it's zodiac stars before the polar ones.
A star map for such may look like this:
Where Green is very close the core's ecliptic inclination, Red is almost polar directed.
Routes, may even pass through some tropical stars if their space travel technology is advanced enough to maneuver into inclined systems, still, not enough to enter and stabilize in polar reference planes.
Here is what I mean, seeing the core system from a polar perspective, orbits polar to that of the core system, will appear almost - if not, parallel, to the viewers perspective.
And then, there is celestial latitude, ie, how far away into the poles - the target star is from the ecliptic equator.
As Earth's inclination is concerned, the maximum natural trajectory inclination a rocket can be launched at without correction, is about 23,5°.
We could say then, that the most natural route to another system will be also limited to it's position in the core system's sky.
Again, the closest star to a said system is 5ly away, but it is in a polar inclination and a polar plane relative to ours, and thus, the closest outpost may be at 8ly away.
This combination of Ecliptic Inclination and Ecliptic Latitude can create maps such as this.
Let's color the systems by Latitude, Green being along the Ecliptic, and Red and Blue being above and bellow the Tropics.
And then, we switch to a sideways view of this particular star cluster.
As each system has it's own launch limitations, our empire shall colonize systems which limits do overlap, for example, the upper right green system can't directly reach the upper red system, it needs to run through a long scale of systems that overlap each other's launch boundaries, until it reaches the upper orange system which does overlap with the upper red system.
Now THIS, is what we're looking for, we just established the way routes are drawn through space. Even though ships in a sea nowadays can travel in any direction, is more cost efficient to travel along marine currents - in space, we're looking for plane inclinations similar to our ecliptic plane.
As a matter of lore defining facts, for instance, the middle yellow star in our map is a very important choke point, in fact, the only route to the other half of the map, or the upper orange system, is the only path to the upper red system.
POLAR ROUTES
As we've seen, planets orbit and rotate along the star's ecliptic plane (in our system, Earth defines the ecliptic). We'd expect that most of planets around other stars - also rotate along the ecliptic with a few variations, like Earth's 23,5°, or Jupiter's 3,13° of axial tilt.
Still, a system like ours would be very important to stellar routes, we have Uranus, a planet with an axial tilt of 98°.
As the planets orbit the Sun along the ecliptic, moons orbit their planets along the equator with little variation, for instance, our Moon's orbit is tilted 5° from the equator.
Here is Uranus' moon system:
If we could build space stations and launch pads along Uranus' moon system, we could access polar stars and polar inclined stars, for their system's resources.
Imagine allocating your civil population among polar coordinates, with a few choke points in star systems like ours, which can be turned into strongholds or military cores, were all you have to defend is a single planet or moon system, in order to protect a couple or even a dozen civil systems.
Or either, using those polar routes as loops to overcome stellar blockades along a certain plane of reference, jumping over or bellow enemy controlled systems.
The downside of Polar Routes, is that other civilizations may live in those, and thus, the use or not of those polar routes is defined by politics between those civilizations, paying taxes to access the Y-axis of the star cluster may be of great importance in case of war, or even, the reason for blockades or a space war.
Here is side-view map of a star cluster, the < shapes represent the maximum and minimum angle of launch from a certain planet in that system. The particular blue < signals a polar inclined planet analogous to Uranus, and thus the access point to the red star at the bottom.
And thus, we also justify why you wouldn't have to circle an entire planet to blockade it - only the equator, with cruisers or space debris, leaving launches from tropics and poles as expensive and risky as possible.
Forget the food, water or minerals, aliens may want to invade the solar system to use Uranus as a polar loop between stars - because they are fleeing from a greater force, and as we humans are still living in the inner system, they won't have to wage war on humans for a long time...
- M.O. Valent, 06/02/2020
