There're about ten manned space stations around Earth in 2076, plus a Moonbase or two, and a Mars base. There's an Ares station aroud Mercury-ish that studies the Sun and is manned, and there're a few othe rthings lfitting around out in space as well. There's a whole big bunch of info about this in Hazard Pay. Is cool. 
If that's the case, then I'd suspect that nuclear rockets are in use. They'd have to be just to get to Mercury-ish and back again, because Mercury is so far away. I'll have to look those books up and read up on them, because I'm curious as to just what it is that Ares is hoping to get out of doing manned research so close to the Sun. Must be something around up there that has their attention.
There is another point that I'm not sure about, and it comes down to Space Sovereignty. We have something already on the books known as the Space Treaty, which basically says that we won't put nuclear weapons in orbit and that the Moon and other celestial bodies aren't really owned by any one nation, among other things. However, since the changes made in the 21st Century, that treaty may be null-and-void, or ignored altogether. If there are only a couple of moon bases, I wonder if that means that someone, be they a nation or a corp, declares some ownership of the moon and all the rights to explore and utilize it? Or, at the least, the small portions of it that the bases occupy? Even if nothing were to happen in our real world but we put moon bases up there, the more we do that the more that territoriality is going to become an issue. This is especially going to be the case if we start exploring and posting facilities on asteroids like Ceres.
When that happens, lots of things could happen, but one thing that could happen is that hostilities break out, and that means a space combat scenario.
I and a lot of others around my circles have pondered what this would look like. Space combat is markedly different than planetary combat. I don't know if there are armed spacecraft in the Shadowrun universe, but if I had to guess they probably don't look anything like what we might ordinarily imagine. And, as far as I understand, I don't know how well Magic works in space. I know that you don't want to go Astral in space, but do spells work in space? Because that's the only way I can see anyone being able to conceal a spacecraft, spacestation, or any other manned space facility. Without the ability to somehow cast an illusion that obscures infrared sensors and radar, detecting spacecraft will be stupidly easy, because they give off so much heat. Spacecraft do not get rid of heat very well, because there's no medium to help get rid of the heat out there than it does on Earth. Half of those panels you see on the ISS are not solar panels; they're radiators, and without them, the crews would roast.
Basically, from what I know of the Shadowrun universe, there would be only two ideal weapons to employ in space: Lasers and railguns. Lasers have a whole lot more range in space than a railgun, but they suffer from the Inverse Square rule, that the further out you shoot, the less powerful the beam will be at the business end. So while X spacecraft armed with a laser could shoot from a million miles out, the damage he inflicts on Y spacecraft will be negligible, but increases as the ships get closer in. The X ship would punch a few holes (which is why both spacecraft will decompress and their crews will be in spacesuits prior to combat), but may not damage it enough to neutralize the Y ship. And if the Y ship is armed with a railgun that only shoots BB sized rounds in one shot-gun like blast, he has to get in real close, within a thousand miles, of the X ship. But, the Y ship has to only hit the X ship once. If only one BB moving at several times the speed of sound hits the X ship squarely, or even just at a small portion, the sheer kinetic force will obliterate it.
