Skip to main content

How do spacecraft survive atmospheric re-entry?

Every crewed spacecraft has a heat shield of some sort. When you enter an objects atmosphere, and it is thick enough to produce a good amount of heat during entry or re-entry, like Earth, Venus, Mars, and more, you are going to need some sort of heat shield.

There are 2 main types of heat shields (these are the most common ones), ablative heat shields and heat shields that absorb and contain heat. Most spacecraft, including the ones that took people to the moon and back, in 1969-1972, used ablative heat shields. An ablative heat shield consists of a type of material, when exposed to extreme heat temperatures, turns into a gas and carries the heat away. Obviously, these cannot be reused easily because a good fraction of the material would have ablated away due to re-entry. Since The Sun has energy and releases a ton of it every second, the heat shield would be exposed to energy emitted from the sun. This is why they often spray a protective coat on the heat shield that can reflect as much sunlight as possible before re-entry to prevent as much material as possible from ablating away.

So yeah, ablative heat shields seem pretty reliable, but what about that other type we mentioned before? This type of heat shield, well, doesn't exactly have a name. It usually consists of many different heat shield tiles which instead of turning into a gas when exposed to high temperatures, absorbs heat and contains it. The Space Shuttle used this kind of heat shield, and consisted of silica tiles, made from pure quartz sand. This heat shield protection had prevented heat from reaching the aluminum-skinned orbiter part of the space shuttle, what most people like to call the actual Shuttle. Yes, the white spacecraft that sort of looked like an airplane.

Well, which one is better? They are both good, and pretty reliable. They can both average somewhere around the same price, because depending on the type of material you use, you can't really say one cost more than the other. Reusable heat shield tiles that absorb heat are better because they can easily be reused with minimal refurbishment, and are simpler in most cases.

The conclusion is, without a heat shield on your spacecraft, you will not survive the brutal heat from atmospheric entry on Mars, and most near Earth sized planets with an atmosphere like Earth's.

Popular posts from this blog

Starship SN10 Aborts at T - 0 Seconds for its 10km test flight.

  Moments ago, Starship SN10 attempted a flight to 10km, to then orient itself into a unique horizontal bellyflop position, flip itself upright after it has descended to about 1km, deploy the landing legs, and touch down on the landing pad softly. This vehicle, Starship Number 10, uses Liquid CH4 (methane) and Liquid Oxygen aka LOX/LO2, used by its 3 powerful Raptor engines.  Today, SpaceX started their official stream for the Starship SN10 Flight. SpaceX have privated the stream replay, so we cannot replay it. In case you want the link: The vehicle began fueling up with Methane and LOX, and then shortly after, it started the engine chill process, which is the process of chilling the engines down in preparation for engine ignition, so the engine material does not crack or get damaged from sudden shock. The vehicle attempted to start up its 3 Raptor engines, by opening the fuel & oxidizer valves, starting up the turbopumps, sho

What is “the best” programming language?

Programming languages, there are so many of them. Some programming languages are way easier to learn than other ones. But which programming language, is “the best” programming language? This question, it is not really answerable. There is no “best programming languages”, they are all meant for different things, well, MOST of them. If I were to compare 2 different programming languages, meant for very similar things, like Batch and Bash, I would say Batch is easier, as its Syntax is not as confusing as Bash’s to the average person. Here is another example, C# is primarily used for computer applications, mostly on Windows, and HTML is a markup language, being used to make websites. I cannot compare C# (it is pronounced “See Sharp” if you didn’t know) because they are used for completely different things. It wouldn’t make sense to say, “C# is way better”, because what is it better at? Developing desktop applications? Sure! Then I can say HTML is better at making websites, it is not a logi

How do you know the universe was not created a few minutes ago?

       The universe is the giant area of space that we live in, which is observable. Anything past our universal border is not in our universe. People do say the universe is constantly expanding, but there is no proof of that, as the "imaginary" or, maybe not imaginary border at the "end" of our universe. But, how do you know that the universe even exists? Were you even in it last week? Did last week even exist? Last week, the universe could have been created, and you do not have proof against it. All of your knowledge and memory could have easily popped into existence a few seconds ago, tricking you into thinking you have existed for longer than you think. This is likely, but also unlikely, it is a 50/50 chance. A reason that this is unlikely is, there are a lot of things that do not make sense in our universe. Like, why does matter attract matter, resulting in gravity? This exists in our universe, but can it exist in a different universe? Not really, or most likel