[Pennywise]

Would anyone wager a guess as to what this means?

スペースサブナード

It's part of a spaceship, so I'm thinking it might possibly be a made up term.

[Niahak]

Further context: scan from instruction manual where its location is labeled.  It's in the right-most image, in the "tooth" of the Corona.

http://www.niahak.org/jesus/jesus007.png

High-res, so the image is pretty large.

Wouldn't surprise me if it was a term from some classic (70s and earlier) sci-fi that I'm not familiar with, since the game uses some terms from that genre.  The component of the spaceship itself is only shown once in-game, where it's used as a view-port into space.

[LostTemplar]

サブナード usually means underground ("sub") promenade, but judging from the images that doesn't make sense here at all.

[Niahak]

Well, it's only used during the one time people can relax... so maybe it's a sort of area for the crew to take walks.  It seems a little small for that, but it fits with what little usage there is.

Still not 100% sure what to name it in English.  Leisure Area or something, maybe.

Thanks!

[Paul Jensen]

I agree with LostTemplar. It means "subterranean promenade". Apparently there's an underground (as in, below ground level) shopping district in Shinjuku called "Subnade".

I guess it wouldn't make a whole lot of sense to use "sub" if it's in space. Maybe you could call it "SpaceMall" or something like that.

HTH