ΔE 17.6, loose: different enough that you should pick on purpose. Zombie Flesh is noticeably darker, cooler than Space Dust.
Not as a straight swap; see the closer alternatives below. Loose match (ΔE 18). Zombie Flesh is noticeably darker, cooler than Space Dust.
The same difference applies the other way round: Space Dust is noticeably lighter, warmer.
ΔE is the colour difference between our two swatch estimates: under about 6 is close, over about 15 is loose. Real paints also differ in finish, coverage and how they thin, so test before you commit.
See Space Dust on the colour wheel See Zombie Flesh on the colour wheel
All matches: Space Dust equivalents · Zombie Flesh equivalents