不知轻重

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.

知 = 口 + 矢 : Mnemonic symbol: Francis Bacon is attributed to have stated "scientia potentia est", "knowledge is power". I'll thus represent 知 by Francis Bacon. Francis Bacon (知) and James II of England (zh) are playing darts (矢) in front of the space station (Ø1). Because they lack a dart board they just use a mandarin (口).

轻 = 车 + 又 + 工 : The Queen of Hearts has been training a lot recently and poses before her next boxing battle. She's driving around in her cabriolet bending steel beams wearing her boxing gloves easily, swinging the beams as if they were as light as feathers.

重 = 千 + 里 : Mnemonic symbol (from the shape of the character): this one looks like a space elevator. The two top strokes are the heavens, the two bottom strokes are the earth, and the part in between is the cabin (or climber) of the space elevator.

Chantal Chicken (chu) is working in the engine's kitchen ((e)ng2). Her job is to crush sunflower (里) seeds with a 1 kg weight (千) to get the kernels. Then she has to put the kernels into the cabin of a space elevator (重) to send them to outer space. This repeats (重) again and again day in, day out.

重 = 千 + 里 : Mnemonic symbol (from the shape of the character): this one looks like a space elevator. The two top strokes are the heavens, the two bottom strokes are the earth, and the part in between is the cabin (or climber) of the space elevator.

Julian Giant Squid (zhu) installed a space elevator (重) in the engine's bathroom ((e)ng4). For the maiden trip, and as a stress test, he loads one thousand (千) one kilogram weights (千) and decorates them with sun flowers (里) to celebrate the occasion.