Why Satellites Do Not Freeze In Outer Space

One of the most widespread myths regarding space is that everything that enters it instantly turns into a chunk of ice. Since there is no matter in space that can transfer heat, it is a vacuum and is neither cold nor hot. Space lacks a medium to conduct heat away from objects, which is why spacecraft like satellites and the International Space Station do not freeze there.

In simpler words, space is neither cold nor hot because it is a vacuum, which means that it contains no matter that can transfer heat, according to Forbes. Space objects, like satellites and the International Space Station, do not freeze because there is no medium in space to conduct heat away from them. Also, the vacuum in space is very different from the one we experience on Earth.

It is true that space is an unquenchable heat sink, which means that you can give it energy indefinitely without heating it; however, it is also an excellent insulator (vacuum), which also means that you can only lose heat to it by radiating infrared, a slow process, Forber reports.

However, space differs in two significant ways: it is cold (especially if you are not in direct sunlight or are far away from the stars), and it is the best pressureless vacuum we know of.

Thus, the real concern for most spacecraft operating in the region between the asteroid belt and Venus’ orbit is overheating in direct sunlight. Reportedly, spacecraft are able to manage this by rotating occasionally and using reflective insulation to regulate interior temperatures.

The removal of heat generated by onboard machinery (and occasionally by passengers) presents the next challenge. Radiators are typically needed for this, and in order to keep them from overheating in the sun, they need to be painted a light colour and relatively large, Forbes adds. Sometimes, instead of using a big radiator to reject heat, water ice sublimators are utilised, such as in spacesuits.

In addition, the focus now switches to staying warm as you get further away from the sun (heaters are powered by radioactive thermoelectric generators) and staying cool as you get closer to the sun (at least one near solar probe spent months hidden behind a sort of reflective tent).