Orbital isn't as straightforward as the other maps, so I threw this together. Hopefully it helps close some mental gaps. I know I struggled with it for a while, but it's a pretty interesting setup.
From above, you can tell that there's only a few main areas, but the confusion comes into play with the corridors overlapping and the lack of authentic symmetry. To better understand, the red level is the upper floor and the blue level is the bottom floor. The green areas represent the stairs which bridge the two floors on both sides of the map.
Here are some shots to connect the dots for those who are still questioning their bearings on the map...
Red base and blue base above, respectively. You might be able to see a few of the access points of each base. There's one door which is always open and one which is closed on objective matches, allowing players to hit a green keypad on the inside of the door to open it. The latter has an orange band around it and Mongooses facing through it.
Another shot of red base shows the upper-level of the base itself and the hidden access point just to the left of the terminal. Beyond the Mongoose, those windows look down into blue base (and vice versa), as shown here...
The main door of each base (the one that stays open) accesses sections C and D on the map. They act like an antechamber for the base, giving you access to stairs and the corridors at the center of the map (E and F). Both of these rooms are color-coded for their adjacent base, as shown below.
Going straight through this room to the stairs takes you deeper into the map, but if you wanted to circle back, you can, by heading toward the right (red) or left (blue) to get to the corridors at the center of the map. Taking this turn lets you take the secret passage or, if the door's open, the second access point of the base, as shown for red and blue base below...
Instead, if you were to head from red base, through the antechamber, down the stairs, you'd find yourself here, at sniper...
You can get there from blue base as well, but just slightly differently. Instead of heading through the antechamber to the stairs, you would head down the F corridor, toward the rocket spawn and the infamous pit of death.
The last shot shows you rocket spawn, which is not far from sniper but separated by an imperceptive distanced jump. You can make it, once you get the hang of it, but it's not easy.
Let's say you wanted to rush the rocket spawn from red base though instead. Rather than pushing through the antechamber into the stairs, you'd take the E corridor toward the window at the far end...
The shots above are in sequence, looking back toward red base as you travel down E corridor, the final one being the window looking down at Ecuador's coastline. If you kept backing up from the window, you'd run into rocks...
Blue base can get there quickly as well, but they have to move through their antechamber, up the stairs to the second floor and turn left at the end of the hallway.
That flooring is kind of clever in the room located just below the letter G on the map above -- here's a closer look:
There are some interesting junctures where players can see each other, but can't fight immediately. Like right here, near the sniper/rocket location.
Overall, the map is rather complex. It doesn't have the organic immediacy of Assembly or the simplicity and openness of default Sandbox. That said, Orbital has some potential. It remains to be seen what type of legs it'll have and whether or not it'll be versatile enough for more than a gametype or two -- which was my original concern.
Hope this helps some people. If not, it helped me. ;-)
Happy day!