lucky / giga- (meaning billion or 10^9) / surname Ji / abbr. for Jilin Province 吉林省[Ji2 lin2 Sheng3]
吉
=
口
+
士
:
Mnemonic symbol: "Giga" apparently stems from a Greek word for "giant", so I'll represent 吉 by a giant.
The giant (吉) just entered the space station's kitchen (Ø2) and is very hungry. In each hand he holds Joan of Arc (ji) and the bachelor (士) captive and robs them for their mandarins (口) which he longs for.
big; large; great / older (than another person) / eldest (as in 大姐[da4 jie3]) / greatly; freely; fully / (dialect) father / (dialect) uncle (father's brother)
大
=
一
+
人
:
The big (大), huge (大) robot (mnemonic symbol for 大) is working out in the ashram's bathroom (a4). He's lifting a flute (一) to which Don Quixote (d) and Neanderthal man (人) are clinging.
to learn / to study / to imitate / science / -ology
学
=
小
+
冖
+
子
:
Xu Xian wants to study scienceology and learn more about daisies. Just inside the elevator's kitchen, he put some daisies into a prize cup and covered them with a cooking top. He wants to study the growth rate of the daisies depending on the pH of the water in the prize cup.