Deep space

Deep space referred to more empty regions of space, between stars or galaxies.

Sector 16 (TV: Earthshock) and the fifty-fourth sector of chartered space existed in deep space. (PROSE: The Dimension Riders)

Space Station W3 was, among other things, a stopping point for deep space ships. (TV: The Wheel in Space)

When travelling through deep space, one could experience deep space sickness. (TV: The Space Pirates) Oxygen and water were considered precious things while in deep space, as anyone having undergone space travel training would know quite well. (TV: The Wheel in Space)