Excerpted from Alliance training video NBT-013, Introduction to Jump Astrogation, 2058:
"Okay, one of the first things that most beginning navigation officers worry about is how to grasp navigating in three dimensions. Luckily, that's not actually an issue for you. Your tactical officer will handle the ins and outs of 3D flight. For most intensive purposes, space is flat. Both in terms of in-system travel and jump mapping.
Let's start with in-system travel. Here we see a holomap of the Solar System. Notice as I rotate the map how most of the planets lie together on the same flat surface, like this. This is called the plane of the ecliptic. All the major planets' orbits are within 7 degrees of this plane, meaning that the solar system is essentially flat. For the purposes of this course, you don't need to understand the physics involved, such as angular momentum. If you're interested, see your training officer to obtain course NAT-017, Advanced Orbital Mechanics. The important thing to know is that our system is not unusual in this respect. The vast majority of star systems we've encountered have a similarly low inclination in their planetary orbits. They're flat, too. The one caveat is that small point targets such as asteroids may not behave the same way. In this view, you can see the largest 300 asteroids in the Solar System. I've removed the planets to make it easier to see, but this red disc represents the plane of the ecliptic. While a large number of the asteroids are relatively aligned with the ecliptic, you will notice a signficant number of outliers, including some such as 136199 Eris, which orbits at a 45 degree tilt to the ecliptic. You will receive additional training in plotting navigation strategies for these kind of targets in course NAT-004, High Eccentricity and Inclination Navigation.
Now, as regards jump navigation. Here is a three-dimensional representation of the nearest 20 light-years around Earth. And here's an overlay of the known jumproutes discovered by Survey Command to this point. As you can see, that's quite a mess. One of the first thing scientists discovered when we first began surveying extra-Solar space was that the jumproutes didn't conform to a logical progression from near to far. Here's Proxima Centauri, the nearest star in realspace terms. But as you can see, you have to make three diffferent jumps to get there, going as far as twenty-two light-years away before coming back. So we developed the Ring system of mapping. Since each jumproute is two-way and there are a finite number of jump point per system, they can be mapped as a two-dimensional concentric series of rings, like this. Much clearer, isn't it?
There are six systems in the First Ring: Wolf 359, Lalande 21185, Luyten 726-8, EZ Aquarii, Barnard's Star and Charybdis. Although I encourage you to memorize the cartography of all six, you really only need to become familiar with the first four. Barnard's Star was determined to be a dead-end, so you'll probably never travel there unless you go to work for a mining concern. And Charybdis is a Class II singularity -- a pocket black hole. Beyond it lies the so-called "Charybdis Pocket", two interconnected systems that create a triangle, as you see here. There are no worlds of interest in the Charybdis Pocket, and given the hazards of skirting Charybdis' event horizon, UniCom has issued an interdiction on commercial activity and exploration in that segment of the jumpweb.
Beyond the First Ring lies, as you would expect, the Second Ring. You see the system names listed here. There are thirteen all total. These have been well-explored with the exception of Tau Ceti. . . I don't think I have to explain why.
And here, the Third Ring. 22 systems, and at this point in time most of them have been fully grav-mapped, with the obvious exceptions of YZ Ceti, and Glieses 1 and 408. UniCom is convinced that travel in systems adjacent to the interdicted zones is safe. Neither the Wraiths nor the Swarm have shown any indication of jump technology.
And out here, the Fourth Ring. 29 systems in all. This is the frontier. If you're lucky enough to be assigned to an Explorer, it will be your job to map these systems and push the frontier further back. Of these, note that Wolf 1061 and Groombridge 1830 are also interdicted. And here, in SZ Ursae Majoris, you see the Bastani. If you've taken your xenozoology courses, then you already know about them. If not. . . well, you're in for a treat. They may look a bit. . . odd, but so far they're the only ET that hasn't tried to kill us. They seem friendly enough, but as always caution should be exercised if your orders carry you into SZ Ursae Majoris. They have a sizable fleet and although we don't know its capabilities, it's safe to assume that they're comparable to ours. Courses WBT-011, Bastan Empire Vessel Identification and Capabilities and DBT-02, Understanding the Bastani are strongly recommended if you are posted to the Aquarii sector.
Now that you have the basics of how your "roadmap" is laid out, let's take a look at the mechanics of jump travel. . . "