Heat Shields - Things Kerbal Space Program Doesn't Teach 

Reason #1947461 why Bruno>>>> Musk, Bezos & others

Very interesting, thanks for the response!

Thank you!

Very interesting stuff! What exactly is meant by 4D weaving of carbon fibers? My euclidian space only offers three orthogonal planes, so I would assume there are some non-orthogonal planes?

pog

Thanks for the extra detail

I'm gonna have to go ahead and ask you: have you been using the new cover sheets when you file your reports?

are you saying I shouldnt use elmer's school glue for my heat shield tiles?

@@Blox117 extra credit if the densifier was PVA

@@jimbarino2 You know how many times I have heard that one over the years? :)

Go to the Smithsonian Museum, Kennedy Space Center and the California Science Center to see 3 space shuttles with over 30 flights each. Keep in mind that all future spacecraft were based on this 1970's reusable technology. Show a little respect.

divedevil985 it was a bit of a big Oof is all, mad respect but yeah they had to be refurbished a bunch

@@divedevil985 yeah but reusing them was more expensive than not reusing them would have been, so that effort was pretty wasted.

@@Chuckiele Bruh. Are you serious or are you joking? While thats the case with the SRB's the Orbiter and the ET... Not so much

@@youravaragejoe5102 The SRBs were just the tip of the iceberg, where refurbishing basically meant stripping them apart and rebuilding them entirely with only the casing being actually reused and that was damaged badly by the salt water. The Orbiter had two major issues as well. The first one being that the original design had less cargo but internal fuel, the design they eventually went with had much more cargo and no internal fuel so that it needed an external tank. However for some reason they forgot to move the engines below the external tank. Instead they were dead weight on the orbiter once the tank was dropped. The engines themselves were extremely expensive to refurbish because they were a very complicated design. Expendable engines strapped to the external tank would have been cheaper while achieving the same result, except that the Orbiter would have been lighter as well. The second issue was the heatshield which was very expensive yet very fragile and thus every tile had to be checked and replaced if needed after every flight which was very labour intensive and stripping off an ablative heatshield and reapplying it entirely wouldnt have been more effort but would have been way cheaper in material costs.

It’s not just Russian.

Scott Manley ohhh?? I thought they were the only ones who flew wood as an ablative heat shield.

@@colingrain8793 As far as I know another good material for this is cork. It gets charred at the surface and forms a protective layer for the cork underneath. Takes very long to burn through..

It is Chinese technology for you.

@@quoniam426 also known as rip-off Russian tech.

love it

injustice fellow I posted mine 3 minutes earlier

injustice fellow Don’t worry though, I forgive you

lol

You both get a like ;)

Check out CuriousElephant,If u havent yet.. .Im Sure ull love him

Master Ed -- Yes, Scott Manley, (together with a handful of others), is my place to go for space-in-the-present. Scott gets to the point, and us updated, done. PS. I like the reference in your name to a TV-favorite of mine.

Pretty much why Matt Lowne inserts Scott Manley memes in some of his music videos.

Hmm, fly safe!

@@tubularap thanks but this is what everyone called me anywhere I went, they still call me Master Ed

Ahhhh there you are! videos feel empty without a comment from you

Hey boss

You will be the next Justin Y.

Belated happy birthday ;)

Wait until your father hears about this, mister.

Pretty much.....

It was an interesting time

well there were some wooden ones aswell

Bakelite can't even stand a couple of hundred degrees, let alone a couple of thousand.

Why not?

Important safety tip!

pikaa

PikaCHu

Pika x2 = Pika Pika?

That sounds like a Citation Needed ending joke (Pika 2 pikachu).

ah, ah, AH!!!!!!! Pikachoo!

Indeed. Even a bullet - perhaps the fastest thing in most people's minds when they think of speeds that are in some sense "relatable" - is in a sense dog-slow compared to a reentering spacecraft. A handgun round, for example, may travel at only 300 m/s or less (= km/ks, handguns especially are usually made to keep their rounds subsonic so as to minimize noise as a supersonic bullet makes a "snap" as it passes - effectively, a tiny sonic boom, and the speed of sound in air at the usual level where humans live is around 341 m/s or so, though varies a bit with pressure and temperature). Even a rifle bullet (which are "allowed" to go supersonic) only gets to about 1000 m/s or maybe a bit more. But a reentering spacecraft easily plows in at orbital velocity if not greater - that's over 8000 m/s! The (per-mass) kinetic energy dissipated and the pressures involved go up as a square and that makes them on the order of 64 times worse than a rifle bullet! 8000 m/s is fast enough - keep in mind - that it can be used to circle the earth in only about 5 kiloseconds (40000 km / 8000 km/ks = 5 ks, not counting orbital altitude and the thus slightly enlarged radius. The ISS's period is more like 5.5 ks IIRC.) - compare that to a typical international jet flight taking 36 ks (10 hrs) just to go a quarter of the way (10 000 km) around the globe! And what's happening to create all that heat? Effectively, you're _pounding the air so goddamn hard_ that it's not only creating a hypermegasonic deathwind against your craft but that deathwind is as hot a damned blast furnace due to the craft effectively acting like a piston and slamming all that air together in front of it as it's moving too fast for that air to simply flow out of the way, and thus causing it to compress dramatically and heat rapidly: think about a bicycle pump and how as you use it for a while, it warms up. Same thing here only far, far more violent. You're taking 8 km of air - a tube of air as long as a small city - then slamming it into a pancake (or at least a very short cylinder) in 1 second, _every_ second (so imagine in a single second zooming in a crazed blur from one end of your city to the other, buildings, parks, stadiums everything just flying by in the twinkling of an eye, and all that air, that would take you driving it perhaps 400 s or more at city speeds and would brush your hand held out the window like a wind, imagine encountering all that air virtually at once), so that by the time it gets around the edges it's like a blowtorch (this compression ratio reaches or even exceeds that of a diesel engine, I believe, which uses this effect to ignite its fuel instead of using a spark plug as in a gasoline engine, at least going by the temperatures attained.). Naturally this is why the bottom part is where the tiles are, since that's the part used to "attack" and thus compress the atmosphere, making it where the peak heat is reached.

>> close to burning alive/structural failure that re-entry is Re-entry head: 1700 degrees. Temperature at which the most heat-tolerant glass melts: 800 degrees. But you still believe that a capsule with glass windows would survive re-entry.

@@markgerhard1362 _"Temperature at which the most heat-tolerant glass melts: 800 degrees. But you still believe that a capsule with glass windows would survive re-entry."_ ...What are you getting at? That glass on space craft are a lie? That space travel is impossible due to glass and those clever disinformation agents at NASA were done in by none other than Mark Gerhard's clever thinking? "Glass beams can't jet fuel capsules" or something? ...You do know that glass isn't used as a heatshield, right? It's there... on the sides. Where the heat is much less and can be easily radiated away. And as far as that heating goes, I think the Shuttle utilized around 5 inch thick glass (of whatever type it was, I don't know). Now... Do you think that just perhaps it takes more heat to heat up thicker glass and takes longer? Strange concept, I know, but a small sliver of wood also burns much faster than a 5 inch round diameter tree, too.

@@matchesburn >>You do know that glass isn't used as a heatshield, right? Your hero Scott Manley just said that it was. Check the thread above.

@@markgerhard1362 What "thread"? RU-vid comments are not that organized, so I don't know where you're referring to. He sure hasn't commented in this particular set of replies (that to "matchesburn"'s top-level post).

A true person deserving of the role of astronaut!

Isn't that essentially how the thermal system on the X-20 was designed to work?

Yes I think so too

More like vaporizing

Just ablate what you don't want to eat.

Pack it just underneath the TPS and the little bit of heat coming through should warm it up nicely.

Or as Gene called it, the "biological payload"!

And the main software is very powerful

Tough....Rock....ToughRock. I get it now. Nice acronym.

ESA on the other hand has the Very Large Telescope

@@1224chrisng ESO. European Space Agency vs European Southern Observatory

I keep wondering if NASA first decides on the acronym and then comes up with the full words.

@@0ptera Yes they do. It's called a backronym. See examples such as MESSENGER, INSIGHT, etc. It's really getting out of hand. Too many PR types on the payroll.

They must have an entire team squirrelled away armed with dictionaries and thesauruses whose sole job is to come up with acronyms for the missions. Let's hope NASA never builds a Synchronous Helio-orbital Interferometric Telescope.

Oh the best one is the P.O.E.S one, which is a VERY cude and terrible swearword in Afrikaans

I have a few videos that cover bits of the RS-25 ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-4QXZ2RzN_Oo.html ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-l5l3CHWoHSI.html ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-u6rJpDPxYGU.html

s p e e d y b o i

I live near Kennedy Space Center and when I got to watch a launch from about 7 miles away I was surprised at the weird sounds that were made.

*_Howw???_*

ITS NOT.

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Nope!

Who?

@@drmantistoboggan2870 Tory Bruno, the CEO of United Launch Alliance

It's 4th comment shorted by newest

@@parveshkhatri1027 Thanks!

Poor guy no one read this

Seconding this, I haven't watched any good new airbreathing jet stuff in a while and I'm sure he'd do a great job.

@D r . S p u d Probably not, just a black mark on the mouse or touchpad

@D r . S p u d Computer or not, something is still ending up severely burnt

In my previous comment: “describe” -> “define”

RE: 10:10 Checkout the HYTHERM experiment images from STS-119! (Post Columbia 💔) They intentionally added a boundary layer trip on one of the aft wing tiles and filmed re-entry with an IR camera. Being further aft, the turbulent heating would be within design spec. However, gap filler, or some other unknown roughness source triggered early transition on the fore-body underside. Another hairy situation. The tile with the boundary layer trip is still in place on the space shuttle Discovery at the Smithsonian Air and Space Museum in Dulles VA. Also, another interesting property of C-C-C (carbon-carbon-composite) that the LE of the wing and nose patch is made from is that it is a highly an-isotopic material: the thermal conductivity varies by over an order of magnitude from through the thickness (EXTREMELY LOW) to in plane (higher conductivity, still extremely low).

Great vid. Highly recommend.

@@zbeekerm You are talking about the BLT mod. A friend of mine bonded that tile. He still works with us in TPS. That was a neat experiment.

Helium Road take a look at the hush-hush X-37B

Early Space Shuttle concepts were planned to use a metallic heat shield on top of a titanium hot-structure airframe. But as the orbiter design grew larger to meet USAF requirements, that became unfeasible and forced the switch to an insulating shield on top of an aluminum cold structure. That's also what makes me eager to see what SpaceX is attempting with Starship, since it's something of a best of both worlds by combining an aluminum cold-structure airframe with a metallic shield.

@@thebigitchy That's largely the same design as the Shuttle.

@@pseudotasuki The orbiters grew denser, not simply bigger in volume. In fact a number of the orbiter designs prior to the military involvement were bigger, but lower density because they were mostly big empty fuel tanks and were more like the X-37B in configuration with very small wings or no wings at all (true lifting body designs) since NASA did not need the super high 1500 nautical mile cross range capability.

Sierra Nevada's Dream Chaser has alot of these upgrades you speak of.

Who the hell is this tony guy and why is everyone talking about him?

Agreed! This one was particularly interesting.

Does 'denser' mean heavier, here?

It's a shame he didn't call the series "Kerbal Space Program vs. Reality", then the acronym could have simply been KSPVR. :) Agreed about an SRB video, we always need MOAR BOOSTERS.

the man the myth the legend

That's actually a sensible idea, but wouldn't the interplanetary velocity be several times greater than the orbital velocity of the fuel?

@@rohanpotdar908 They would need to get the fuel tanker up to excape velocity to meet the incoming vehicle which would be pointless.

I wonder who's going to pay for that setup. I can't imagine payloads and projects valuable enough to justify that, IMHO.

Or you could just take the time to bleed off energy through multiple orbits. So long as you can at the very least CAPTURE in that initial pass without destroying the craft, you can make as many passes as needed to slow yourself down to a LEO, where the speed on reentry is as low as possible.

@@hatman4818 Those far orbits would add at least several extra weeks to the time of the trip. May be worth it but, ISRU is the whole point of using this system and should enable the BFR to come back with a fair amount of delta-v.

This might partially answer your question. From what height would you need to drop a steak for it to be cooked when it hit the ground? what-if.xkcd.com/28/

Genius

3 minutes

Probably a few nano seconds, totally hardboiled. Probably where flubber came from.

Many science fair projects are competitions to see who can drop a egg from the greatest height. Your egg, perfectly cooked or not, would certainly beat the record!

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And since its pushing the plazma in front of the vehicle it would slow down even more

I believe it was the ATV vehicle by the ESA, I think it was there to resupply the ISS.

@@cheesegrease8247 ATV helped to keep the iss in its orbit not for resupply.

@fenton bevan no... its an atv

@Luke Skywalker Well both actually

To me it looked like a replay of Shuttle Columbia when it's reentry failed.

Wow, you get notifications from RU-vid, I didn't know that was possible!

You have to Subscribe and activate the bell next to the subscribe button

Sounds interesting! Is it available to watch anywhere online?

Yep! Its on my channel (scroll down to "The Final Frontier" playlist) or you can find it by searching "Atomic Frontier Down to Earth".

@@AtomicFrontier yeah... I suppose a search would have been the obvious option... but it's 2:30am in Australia and I'm rather drunk. :) Look forward to watching it, cheers and a happy new year to you and your family!

Haha, sounds like a good time. Happy new year to to too!

Well, if you have large windows, you could just put a space blanket inside of the curtains, and keep them closed during the heat. People here used to do it with those thick old curtains, works quite well

Nah, I'd say it was pretty heavily baked.

@@ComradePhoenix I know I was :D

Math, like if you knew the temperature and the rate at which the ablative material ablates at a given temperature and the time duration you could figure it out

the change in weight of the aircraft had to have something to do with it

My guess is that they analysed the change in deceleration due to the loss of mass

I suppose if you know the pressure of the atmosphere you are in, it’s density and the rate of acceleration, and the weight before reentry, you can find out how much your mass changed in order to match your acceleration. Properly could tell after the deployment of the parachute.

The follow-up mission of course, that found the heat shield at the bottom of Jupiter's atmosphere.

It probably is cheaper and faster to do it this way. The tiles where extremely labour intensive to maintain and replace.

I remember seeing a video on youtube about flat thermal tiles as next generation research

Read about TUFROC which is exactly what you describe. It only became available in the last decade or so of the STS program.

there was also some problems with bureocracy and politics, and they were not allowed to replace parts of the space shittle with more moderns ones because of it.

If the Dragon heat shield is a single piece, like it seems to be, it's much easier to replace than thousands of individual tiles.

Upload a video of it

more pipes

I think most of us did not need this advice Will Hunting...

R/iamverysmart

it probably only works for a sphere in a void anyways.

maybe NASA is very afraid to even entertain a sense of humour.

I remember reading they did considered something like that, technology probably wasn't there.

The major difficulty is getting the stuff to adhere and not get knocked off by vibration ,pressure, expansion, etc.. It was always technically possible to have a layer of single use ablator underneath the tiles as an emergency measure in case the tiles broke off, but theres mass considerations. Perhaps a good solution would be to have mounting points underneath each tile, bolt somekind of support structure which can be cut to shape to those mounting points then laboriously fill it with caulk like the old apollo heat shield.

No, the mission was for the DOD meaning any and all details concerning it were classified. The tiles themselves weren't classified technology.

It was a different era.. the Cold War was in full swing. Paranoia was everywhere, and not just in the military.

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