General space:
* Spacious: Describing something that is large and has a lot of space.
* Spatial: Relating to space, or the arrangement of things in space.
Outer space:
* Cosmic: Relating to the universe or outer space.
* Extraterrestrial: Originating or existing outside of the Earth.
* Celestial: Relating to the sky or heavens.
Other possibilities:
* Airy: Light and spacious, like a room with high ceilings.
* Vast: Enormous in size or extent.
* Empty: Containing nothing.
The best adjective for your specific context will depend on what you are trying to describe.