I utilized teh Rim but only as an add-on t the original AD Frontier map...in other words none of the plague systems or megacorp systems etc, those all remain unexplored.

Zeb's map names are given for reference to that map.

I have the Zuraqqor worlds adjacent to the Sathar worlds, operating in a "this is my side/that is yours" co-op agreement.

YMMV

The S'sessu, if used as an optional race, would definitely be independentof the UPF. They would be trading partners, some of the S'sessu nations might sign military alliances with the Frontier, but I doubt they'd want to join the federation any time soon. The minor races from Star Frontiersman and Frontier Explorer are good single-planet races that can be scattered around. The Sathar, Clikk and Zuraqqor are all out there, somewhere.

Q. Do you use the Rim, whether the original Zeb's version or something altered?

A. I would use the Rim, but not the way Zeb's provided.

Although the infamous Zeb's timeline -- which I've noted is discussed at lenght by others elsewhere on this forum -- provides some badly needed structure, it really messes up the flow of the modules. This is especially true with the Volturnus adventures. That's probably because the Zeb's designers wanted to make the Zebulon system a crossroads where the Rim and Frontier came together like the Babylon 5 series and then introduce the Rimmers early on. To me, that never worked well if you wanted to use the original modules.

More likely, you would have to move the Volturnus adventures to around FY 50, where most of the original Alpha Dawn seemed to be set. You might have the Eorna giving the PCs more of a history of their brief stellar exploration  and that maybe they encountered the more primative civilizations of the Ifshnit, Hummas and Osakar. Later, after the Sathar attack Volturnus again, then a Rimmer strike fleet might show up because they tracked the worm's fleet moving through their area and went to investigate.

If you do that, any Zebs reference to the Capellan Free Merchants helping out the Truane's Star refugees during the First Sathar War and such would need to be altered.  

Q. It seems as if the Sathar must come from someplace. It could be that they mostly live in large deep space craft, and only control a few settled worlds. Or maybe they have a big empire with lots of planets?

A. At the moment, they are that mysterious, villanous race out there, somewhere though there are a lot of other interesting postings on other areas of the forums. It would be really neat someday to have a complete compendium of all Frontier worlds -- with all the details of a system brief and then some -- and then a compete work up on the Sathar... sadly, who would do it?

Q. I think the Star Devil pirates originated someplace beyond the Frontier, yeah?

A. An article in Dragon magazine #98 originally touched on that very subject along with giving some more information about the Truane's Star system. That story said that a Vrusk executive with a small company called MINER (Mining for Industrial use of Natural Earth Resources) staged his own death by the hands of terrorists (the Husps or Human Supremacists from New Pale) so he could set up illegal mining operations on Volturnus. Truane's Star, meanwhile, was thrown into an interplanetary war between Pale and New Pale.

Others I think also linked the Star Devil to the pirate fleet of Hatzck Naar (another Zeb's creation).

Those explanations have worked for me.

Q. If one goes with the AD set up, then the Core Four home worlds lie someplace outside the Frontier. The Yazirians might be from someplace close. Or maybe not. I would definitely go with the home worlds existing outside the Frontier. In contrast to AD, though, I assume the Humans originated on Earth.

A. It's been postulated in the forums and Star Frontiersman that the Yazarians moved en masse to the Frontier after a disaster with their home system (a close encounter with a brown dwarf star). That's as reasonable an explanation as any other for their arrival. It does mean their home system and planet are still "out there," probably with survivors clinging to an existence on their devastated world.

I think Jedion357 also has given some interesting speculation to the arrival of the Dralasites -- that the Vrusk found them in a large Colony Sphere near their home system. The Dralasites had little to no memory of how they got there or where they originated from. That could be one good way to introduce them.

The origins of the Vrusk... again, Jedion357 has some interesting ideas. The Vrusk would come from the Frontier Sector, specifically originating in the Fromeltar system. He says that the Dralasites controlled the translations of the system and the planet's names into Pan-Galactic and that's why they have Dralasite rather than Vrusk-sounding names.

I'm not quite sure I like that complete explanation because of Fromeltar's planets -- Groth has a majority Dralasite population while Terledrom has a Dralasite/Vrusk population.

Maybe, just maybe, the Vrusk homeworld is a third planet in the Fromeltar system. But, the objection would be that three habitable planets in one system is a bit much. What if the Vrusk didn't have Void travel until after they encountered the Dralasite sphere ship. What if they've been stuck in their home system for a while and were terraforming -- or vrusk-aforming -- Groth and Terledrom for some time? Of course, then you'd have to come up with statistics for yet another planet, so that might not be a viable solution either.

Humans from Earth... sounds good. How do they get to the Frontier? I think Jedion357 offered another solution which is that Earth exploerer/colonization ships, not realizing there was a Void, accidentally misjumped an awful long way and wound up scattered on various planets.

That could work, or you could get bring in an Isaac Azimov-style explanation as to why the Core Four settlers seem to appear smack dab in the Frontier without any star routes in or out. (I'll write that suggestion later, however.)

YMMV

Cass was founded by CDC "as a refuge for the multitudes that were left homeless after the Blue Plague" because, well...there simply wasn't enough room for them on all the other sparsely populated worlds in early Frontier history (note the higher population changes from AD to Zeb Guide descriptions, which AD's lower ratings would be assumed to represent said early history). 

Corpco was founded by Streel as "an attempt to enter the agricultural industry" because, well...it just wouldn't make sense to try that out on their headquarter world's in-system neighbor New Pale (which is listed as strictly an agricultural world in Zeb's) so it's best to do that at the extreme far kitty corner of the Frontier instead. Adjacent to White Light, whose planetary goverment has a lengthy history of poor relations with Streel.     

Exodus was simply founded with no reason at all, citing only PGC knows of its use and existence. Why bother listing it at all?  

Genesis was also founded by PGC and is the only one with a valid explanation: a secure base for their research labs. Still, with offices on EVERY Frontier world, this seems moot because there are several established outpost worlds --- worlds which they no doubt already had a hand in establishing/developing --- that could have been utilized for the same reason. See? Bandwagon.  

And make them the older, not the younger, colonies.

They were founded by the megacorps as forward bases, supply centers, and way stations  from which to explore the Frontier Sector.

This is suggested under the assumption that Earth is several years subjective time distant from The Frontier, if not decades because of the lack of any simple jump route chain. A big Coreward Expedition from Earth set off from the Frontier to meet the Vrusks and Dralasites. Bases were planted at likely spots along the way. 

One thing I should consider here is range of effective tachyon communications, assuming I stick with the rest of the Alpha Dawn intro story. Maybe the deep space probes of the Core-ward Expedition were what was contacted, rather than Earth directly.

Note that IMC, PGC or spin off companies would be operating in several sectors of the Galaxy, not just the Frontier Sector.

This is all AD set up, with additions. 

That keeps the Alpha Dawn set up pretty much intact, but shifts the origin of humanity back to Earth itself.

The humans would have been traveling a looooong time to reach such a world, though. Unless maybe they hit 1% of C and misjumped into the Void without any idea what was going wrong (KH FTL style) or something else whacky happened.

Granted if one were to rely on Zeb's Guide as a base for their game, that person has the luxury of ignoring everything from the AD books. 

Just like the Guide itself does. 

Seriously though, adding an "earth" explanation to a game isn't something to condemn or condone. I just don't see the need for it, although back in my teen years I did try an "earth" setting that never made it to my games or campaign.

History may have diverged from our timeline in the Sixties. 

Computing and electronics develops differently. Space tech develops more rapidly.

And, as the module introductory text suggests as a possibility, PGC evolves out of the transnational corporations of the late 20th/21st centuries.

This isn't for everybody, natch. I like having the vast storehouse of Earth history, mythology (Volturnus, Theseus, Minotaur, etc) languages, religions, ecology, toponyms, etc to draw upon. 

EDIT

And if one goes with 38 nuclear powers and high tensions, as per the module, it is possible that a major nuclear exchange jacked up Earth sometime after the big Coreward expedition/ colony ship stuff I have kicked about upthread.

Maybe the corporate worlds Genesis and Exodus can be moved outside the Frontier and reworked.

Genesis is the exoplanet the expedition first reached. But it needed a lot of terraforming. Colonists went through space, STL, and reached Exodus.

Something like that.

It could be one of these planets that the Vrusk contacted.

I dunno, this is all just kicking around half formed ideas.

I get that much, still...I woud think there must be at least a perceived need for it. With that in mind let's examine the population growth between AD and Zeb's to at least try and justify a possible perception.

Have a seat, this is going to be lengthy...
 

Zeb's lists the second Sathar War happening about 20 years later. It's safe to say most of us that played SF before acquiring Zeb's also placed this event some time after Dramune Run, as we were getting our players to cut their spacer teeth withthat module so naturally a full scale war would have to happen later assuming players would be affected by the event in the course of a campaign. So for the sake of this discussion we should agree that fy61/third Dramune War is part of the Frontier's "early" history and as such the AD planetary specifications would apply there, despite being "modern day" to the rest of us that were pre-Zeb's SFers.

Zeb's takes things to "modern day" fy111 and that is where their planetary specifications are reflected. Fifty years later. In fifty years the Frontier has nearly doubled in populated worlds due to a population explosion. Not to reveal my age, and I actually aready have hinted at that in this passage, but I will be coming up on that golden anniversary of my birth in a few short years. Actually, a "few" is over-estimating, by this summer it will be a "couple". The current estimated global population right now is 7.4 billion people. When I was born, it was 3.6 billion. When Zeb's Guide was written in 1983 the world population was 4.7 billion, 1953 had it at 2.7 billion.

Going by both of those time frames our world population has come close to doubling in roughly the same span. How that translates to Star Frontiers...the AD rules would have us as a "moderate" population per the definition: "Several large cities and numerous smaller cities, with no overcrowding." While some traffic patterns may dictate otherwise, overcrowding isn't an issue...there certainly isn't any pressing need for extra-terrestrial colonization on our behalf. It's also safe to say that fifty years ago we were still a "moderate" population by that definition, and doubling our population again in the next 50 years will still have us at that same "moderate" level. While we don't have the need for expansion, we can now see that a population can double in 50 years. So it would seem the peception is there for such business expansion.

Anyways...Zeb's came pretty close to that mark as well, assuming all planets behave the same way. Now I don't know if I should be enlightened, or if I need to consider the Guide having graduated from dumb luck to broken clock is correct twice a day.

Still, I don't see that as a mandate to double the number of populated worlds. But at least the perception of needing more business expansion is spot on. Just not enough to colonize a batch of new worlds.

The difference is when the American frontier was settled, they stopped calling it "frontier". 

The Zeb's map has everything explored/settled, taking it from a frontier setting to a fully civilized setting much like Traveller albeit at a smaller scale.