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In space, astronauts can also drink coffee. The Italian company even delivered an authentic espresso machine to the International Space Station. However, astronauts cannot drink it with ordinary cups.
Imagine the mugs in our lives, whether it’s controlling the liquid or pouring it to the mouth, we rely on gravity. Therefore, these cups are not easy to use in space: under microgravity, liquids no longer follow the direction of gravity, and they will become difficult to control. The hot liquid like coffee floats around, making the trouble even bigger.
What is the solution? If the astronauts still want to drink coffee with a cup, they can choose a specially designed cup, like this:
This look feels a bit strange…
The following is a demo of using a similar cup:
This is a demonstration by astronaut Don Pettit.
Compared with ordinary cups, this cup can better control liquid in microgravity environment and deliver beverages to people’s mouths. The main point to achieve this is that the cup can no longer be cylindrical, it needs to have a narrow sharp corner, we can see that the beverage will spontaneously “climb” up along this sharp corner. This depends on the capillary phenomenon, which is based on the interaction of the solid and liquid surfaces, and the surface tension of the liquid itself. These forces will still exist in a microgravity environment. For the same reason, towels can still be used to absorb moisture in space, except that when you twist the towel, the water will not drip down.
The development of a coffee cup suitable for space use is actually a study by NASA to understand the performance of liquids in a microgravity environment. In addition to making cups, they also hope to make more use of capillary phenomena to make various liquids obedient in space.
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