# The ISS would be uninhabitable without this

## Метаданные

- **Канал:** Real Engineering
- **YouTube:** https://www.youtube.com/watch?v=ZJuI5fImD3U
- **Дата:** 03.02.2026
- **Длительность:** 2:13
- **Просмотры:** 141,049

## Содержание

### [0:00](https://www.youtube.com/watch?v=ZJuI5fImD3U) Segment 1 (00:00 - 02:00)

If space is technically freezing, why does the ISS need cooling? Everything on board the ISS generates heat. The computers, the people, and all that metal absorbs a lot of heat when in direct sunlight. To make it worse, the outside is a vacuum. The ISS is essentially an orbiting thermos flask. Without a way to radiate that heat back into space, the ISS would be an uninhabitable furnace within a day. So, the ISS engineers added these ammonia fililled cooling circuits. Ammonia is chosen for the station's external cooling loops because it stays liquid in the extreme cold of space and is much lighter than water for the same heat carrying capacity. In each truss, a pump pushes the ammonia through a closed circuit, but its toxicity means it must remain entirely outside the pressurized modules. If a leak ever occurs inside, it's safer and easier to clean water than ammonia. So the system is designed with an inside water system that carries its heat and exchanges it with the ammonia outside the pressurized sections. As ammonia heats and expands or cools and contracts, nitrogen tanks connected to the storage tanks absorb the volume change by compressing or expanding behind flexible barriers. This keeps the pressure in the loop stable in all operating conditions. For the radiators to work, they have to face the cold of space. Point them at the sun and the whole cooling system becomes useless. That's why the radiator wings need to rotate, constantly adjusting to keep their broad surfaces aimed into the void no matter how the station moves. But that creates a new challenge. How do you keep liquid ammonia flowing through plumbing that also has to spin? The answer is the thermal radiator rotary joint inside. Flexible hose couplers let ammonia flow through rotating lines. Power and data cables pass along the joint through a transfer assembly, while motors and gears control the swing itself. Altogether, the joint allows each radiator wing to sweep back and forth 210°. To learn more about the ISS and how it was built, you can watch the two-part video series on the Real Engineering YouTube channel.

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*Источник: https://ekstraktznaniy.ru/video/16080*