The spacecraft entering the Earth’s atmosphere is getting hot, but why is this heat generated?
Gas generates heat when pressed and cools when pulled.
When returning to Earth, the spacecraft that enters the atmosphere at high speed presses the air ahead with tremendous momentum.
Then, the molecules in the pressed air collide violently to generate heat.
The heat generated like this is called adiabatic compression.
In other words, it’s not heat generated by friction between spacecraft and air.
If you think of it as something that you can experience in your daily life,
It’s the same principle as if you put too much air in a bicycle and the tire gets hot.
Refrigerator and cooler use the same principle.
Compressed gas gets hot.
If the heat is released to the outside and the compressed gas expands rapidly, on the contrary, the heat around it can be taken away and cooled.
– JAXA. Japan Aerospace Research and Development Organization. In the common question section,