RPG
Although designed as a combination game and setting, the rules are semi-generic, and can be used for any similar space opera setting. To be brief—if you are familiar with Dungeons & Dragons, you will note that while it borrows liberally from many older sword & sorcery and fantasy conventions and details that were common in the early 70s and is often considered to be a "generic" fantasy game, in reality, D&D comes loaded with assumptions on how the fantasy world works. If you try to run Lord of the Rings or Chronicles of Prydain with D&D you'll find all kinds of things that don't fit at all—because there's really no such thing as generic. Rather, D&D is a broad game in that many fantasy settings can be fit inside of the rules, but many will require a fair bit of tinkering, pruning and inventing to fit well. Rather, it's fair to say that there are "D&D style fantasies" that resemble in some points other fantasy settings, but not in others.
As D&D brings with it setting assumptions and any setting that uses those rules pretty much has to buy into those assumptions, the same is true for AD ASTRA. It doesn't shy away from pre-Campbellian (or post-Starwarsian, if you prefer) "non-hard" sci-fi concepts such as psionic knights and space wizards—but it doesn't go the way of Warhammer 40,000 by being so overtly fantasy oriented that it has space elves and space orks, for instance. It's space opera. It's Star Wars and Leigh Brackett and Flash Gordon and E. E. "Doc" Smith and Edgar Rice Burroughs and Dune, etc.
What are the setting assumptions, then? They include, among other things, the notion that old-fashioned melee combat is still something common. People still have sword-fights in space, because it's still useful to use swords in many situations, and the idea of people reverting completely to firearms or vehicles to fight just isn't as much fun. This isn't actually as unrealistic as many people think—people survive gunshot wounds all the time in real life, of course—and modern military and police still use bayonets (pole-arms), shield walls (especially in riot police) and tactical tomahawks and machetes, etc. This is reinforced in the rules by virtue of the fact that the damage of firearms is not inordinately better than that of melee weapons. Not only that, the psionic knights are able to create psionic shields that make them less vulnerable to projectiles, and many of the technological armors do the same.
There is no interstellar communication technology other than sending someone as a courier with news, messages, and information through the bulk, or Outer Darkness. The Outer Darkness is a large extra dimension, as described in various brane cosmology theories, and by using complicated mathematical formula and literal "magic" space wizards can pierce the boundaries of the membrane (or known universe), travel directly through Outer Darkness, and reemerge within the known universe at a given distant point. The point of course would be to travel somewhere that you could not reach by conventional means, as in travel to another star system, or extremely distant travel within the same star system. Travel through Outer Darkness means traveling outside of the normal observed universe, including its 4th dimension of time, so there are some unusual effects of traveling through the bulk—one of which is that no matter how far you are traveling, it seems to require several days (as observed from within your ship) to do so, and the amount of time that passed within the observed universe also seems to rarely be less than about a week. There are limits to how far in real space such a bulk shortcut (sometimes called a jump, or bulk-cut) can take you, beyond which the amount of mathematical variables that can adversely affect the trip becomes suicidal because it's so unpredictable.
This means that traveling by bulk jump ships become something similar to an interstellar pony express at its fastest, which is the only way of connecting vast distances across the setting. This relative disconnectedness means that large central governments are relatively ineffective, and local processes of culture, politics, religion and more dominate rather than broader, galactic ones.
And although aliens exist, this is still a humano-centric setting. In fact, at least a third of the humanity, which is most of the characters you'll see, are the descendants of former northern Europeans and Americans—later joined by smaller contingents of Russian and Chinese settlers. The other two thirds are, of course, humans but not of original Earth extraction, so they represent completely foreign and alien ethnic groups, often with unusual physical features that developed as a response to particular environmental conditions from which they originated.
That's the kind of setting that AD ASTRA supports. Psuedo-fantasy space opera. Swasbuckling adventure. Red sci-fi, not blue sci-fi "men with screwdrivers" and certainly not pink sci-fi nihilistic, anti-Western Civilization propaganda.
NOTE: Attached are two versions of a character sheet. The regular one, AdAstraCS.pdf is a single page, front and back, with plenty of room to make notes and write big. The first page is for the character and the second for a ship. If the character doesn't have a ship, he doesn't need the back page. The second one, AdAstraCD-small.pdf is a single page version of the entire thing; the top half is the character, the second half is the ship, with a little bit of room for a few minor notes at the bottom (and of course, you can make any notes you want on the back printout—unless you use this on a tablet or laptop.)
I like the idea that you can write up a character in a very small space, if desired—although an index card might be a bit cramped unless you have very small handwriting. But a sheet of notebook paper is more than sufficient.
The pdfs are not form-fillable, because I don't create pdfs very often and haven't bothered trying to figure out how to do that. They're really meant to be printed out and written on with a pencil, ideally.
RPG Rules