Questions tagged [ablator]

A material used in high heat flux locations (e.g., atmospheric entry, rocket nozzles) that ablates and carries away the heat/energy of the flow protecting the structures behind it.

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14 votes
2 answers
268 views

Ablative heat shield and conservation of energy, how much does ablated matter in fact "carry away" versus re-radiate the absorbed heat?

I saw Most heat shields ablate, that is they sacrifice material to carry heat away... in a comment under this answer and started writing: I think that shields ablate to produce a layer of complex ...
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4 votes
0 answers
163 views

Has there ever been an attempt or serious consideration for spacecraft to land on Mars without an ablative-type heat shield?

My answer to Do exploration spacecraft enter Mars atmosphere against Mars rotation, or on the same direction? lauds the use of ablative heat shields for minimizing radiative heating of a spacecraft by ...
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2 votes
0 answers
68 views

What happens to ablative nozzles after a test fire?

For example RS-68 engine If you make a test fire of an ablative nozzle engine then the fire will consume the coating of that nozzle. That means you have to replace the coating or the entire nozzle. ...
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5 votes
1 answer
290 views

What is the feasibility of a graphite chamber, nozzle and bell walls

What is the feasibility of using graphite, particularly variants that are easy and affordable to acquire, in a combustion chamber, nozzle and bell as well as nozzle extension? Does it need ...
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1 vote
1 answer
185 views

How much is a typical reentry vehicle decelerated by heatshield ablation?

Most spacecraft (or parts thereof) intended to survive atmospheric (re-)entry use an ablative heatshield, which, when exposed to the strong aerodynamic heating of (re-)entry, gradually ablates away, ...
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10 votes
1 answer
724 views

Who was the first to successfully implement on practice ablative heat shield?

Up until Shuttle/Buran era, all manned orbital reentry vehicles used ablative heat shield for reentry (Vostok, Mercury, Voskhod, Gemini, Soyuz, Apollo). This made me curious about who was the first in ...
17 votes
1 answer
2k views

Apollo CM heat shield burnt pattern around RCS thrusters

Looking through photos of Apollo CM capsules after reentry, I was trying to have a feel for how the heat was distributed on the sides of the capsule. By the look of surviving patches of Mylar tape ...
5 votes
1 answer
655 views

Did the heat shield of the Vostok 1 capsule ablate during reentry?

This Wikipedia article (in german) has some information about the heat shield of Vostok 1. The heat shield was made from asbestos, its thickness was increased from 3 cm to up to 18 cm. The weight of ...
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2 votes
2 answers
481 views

Why would rocket bodies use specifically ablative coatings to reduce boil-off of cryogenic propellants? Is ablation important for this?

The end of YouTube video Delta IV Heavy Pad Tour, (with CEO Tory Bruno) - Smarter Every Day 199 points to Destin's second "Smarter" channel's video UP CLOSE Delta IV Heavy Launch Pad Tour (...
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4 votes
1 answer
122 views

Could a spacecraft produce lift using sublimating material?

Following this question, could a spacecraft approaching upper atmosphere from very low circular Earth orbit, produce lift to soar propulsively, bleeding speed at constant apoapsis, by sublimating ...
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6 votes
0 answers
238 views

Could ablative material sublimation slow down a spacecraft?

Thought experiment illustrated below: Suppose a weird spacecraft entering Earth's atmosphere from low Earth orbit, payload first. Behind it there is an inverted nozzle shaped structure, attached with ...
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5 votes
1 answer
317 views

What properties characterize material as a good ablator?

I know the role and mechanism of ablator, I know some examples, but I still don't know "what makes a material a good ablator". Certainly combustion/evaporation temperature below the expected work ...
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