星
=
日
+
生
:
The sun (日) and a satellite (星) had a love affair and now have a baby: Xi Shi (xi) is quietly sleeping in her little cradle (生) in front of the engine ((e)ng1).
之
=
丶
+
Z
:
Mnemonic symbol: Sooo sleepy... "zZz" (the character looks like a "Z"). James II of England (zh) fell asleep in front of the space station (Ø1). He sleeps on a big petal leaf (丶), making loud "zZz" (之) sounds.
fire / urgent / ammunition / fiery or flaming / internal heat (Chinese medicine) / hot (popular) / classifier for military units (old) / Kangxi radical 86