[Psionic Powers] Astral Projection and Space Travel

[PK]

The "atmosphere" line was actually to avoid the issue of how the Ghost Air enhancement (for Insubstantiality) interacted with the vacuum of space. Fact is, that guideline should certainly be changed to fit the campaign -- for example, I could see a game where psychic astronauts explore astrally because it's safer, while their bodies are fed intravenously.

I don't have plans to lock down the astral plane description any more than it already is -- at least, not in the sense of, "If you use Psionic Powers, this is how the astral plane works and that's that." (Now, specific descriptions of the plane for a given setting are a plus!) Pretty much everything in those two boxes are either (A) intentionally open, to give the GM freedom to define the plane himself, or (B) specific mechanics that do have to exist because that actually is the way we defined astral projection in the book (e.g., using psi across the barrier, astral appearance, etc.). The atmosphere rule is actually one of the exceptions that's neither.

FWIW, I'm working on F N O R D right now, and I think this is a good enough point to touch upon. I'll make sure something canonical says that that sentence is totally changeable without breaking anything.