IPA: /ˈspeɪs.wɚd/
KK: /ˈspeɪsˌwɔrd/
In the direction of outer space.
The rocket launched spaceward, leaving the atmosphere behind.
Spaceward → It is formed from "space" (from Latin "spatium", meaning room or extent) and "-ward" (meaning in the direction of). The word "spaceward" means in the direction of space.
Think of moving "in the direction of space" — that's what spaceward means.