Do you know why spacecraft are wrapped in gold foil?

If you look at the photographs of numerous spacecraft, it immediately catches your eye what they are "dressed up" in. This material is gold and occasionally silver in color, similar to foil. Ever wondered why wrap satellites and probes like chocolates?

The fact is that there is a vacuum in space, and it is an excellent thermal insulator. It is generally accepted that it is cold in orbit - so that people are frozen and break into pieces at any touch. But this is a myth.

In reality, the opposite is true: cool off in a vacuum - that's another task, because there are very few particles in it that can remove heat. At the same time, the bodies there are not protected from the sun's rays by the atmosphere, which would scatter them, and therefore they heat up any objects faster.

So the main danger in space is not to freeze, but to overheat.

To solve the problem of overheating orbiters, NASA's Marshall Space Flight Center, in collaboration with National Metallizing, in 1964

invented the so-called space blanket. Its official name is screen-vacuum thermal insulation (EVTI).

It looks like gold foil, but it's actually represents thin sheet of plastic. Most often it is Mylar, a film made of polyethylene terephthalate or Kapton based on polyimide. Plastic is coated on top with a thin layer of aluminum, and sometimes silver plating. Such a blanket can withstand very strong temperature changes - from -260 to 480 ° C.

It is polyimide, by the way, that gives matter such a bright color. There is no gold there.

"Space Quilt" reflects up to 97% percent sun raysfalling on the surface of the spacecraft, which allows the latter to avoid overheating while traveling through the inhospitable expanses of the universe.

By the way, it applied and on Earth. The metal-coated polymer material is used to create sleeping bags, first aid blankets, marathon and outdoor capes, and more. However, it is deployed with a heat-insulating layer inward, and not outward, in order to conserve body heat.

And sometimes tourists use a blanket in an unusual but useful way - they give signals for help with its reflective surface.