機不可失

机 = 几 + 木 : Joan of Arc (ji) made a machine (机) that fully automatically manufactures tables (几) out of Christmas trees (木) and tests it in front of the space station (Ø1).

不 = 丆 + 卜 : Bruno Bear (bu) is setting up a wind wheel (丆) with a voodoo staff (卜) in the space station's bathroom (Ø4). He also puts a "forbidden" sign (mnemonic symbol for 不) on it, to make clear that it may not (不) be stopped.

可 = 丁 + 口 : Karl Marx (k) is challenging his abilities (可) in the elevator's living room (e3). He tries to force a nail (丁) into a mandarin (口), just by using his head. On top of that he tries to do so one thousand times, in order to create a bed of nails (mnemonic symbol for 可).

可 = 丁 + 口 : Alternative mnemonic symbol: kebab, from the pronunciation "ke". Karl Marx (k) is preparing a kebab (mnemonic symbol for 可) in the elevator's living room (e3). He also skewers mandarins (口) on the long steel nails (丁) and will only allow (可) his guests to eat the rest of the kebab if they eat their mandarins first.

失 = 𠂉 + 大 : Sherlock (sh) locked himself out of the space station (Ø1)! He lost (失) his key (𠂉)! After he was floating in front of the space station for an eternity, a robot (大) came by with a lost+found box (失) which contained his lost key.