Okay, so with that theory, I could see Megacorps using it as a cheap way to move people from Earth to a station. Is it hard to find a Magician with the summoning and invocation chops to regularly move people this way? Eh, for us, yeah, but not really for them, and if it means cutting the distance between Mars and Earth to practically nill, then I can see them investing in it.
But I also really like the idea that you can't. For a couple of reasons. First of all, it means that with the right defenses against Possession and Inhabitation, and a good way of screening for Horror-touched cronies, you could conceivably have a very trustworthy central command in space. But what I find most interesting, is if the Manaspheres don't all connect to the same Metaplanes, could a young Manasphere develop its' own Metaplanes, and see a rise in its own types of unique spirits?