[HN Gopher] Picking up glowing hot space shuttle tiles with bare...
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Picking up glowing hot space shuttle tiles with bare hands (2011)
[video]
Author : mpweiher
Score : 190 points
Date : 2020-03-21 12:08 UTC (1 days ago)
(HTM) web link (kottke.org)
(TXT) w3m dump (kottke.org)
| krick wrote:
| Why can you grab it only on the corners?
| chki wrote:
| My first guess would be less surface for contact, thus less
| heat transfer. But the corners are also colored differently,
| I'm not sure why that's the case. They probably cool down
| quicker?
| krick wrote:
| I assumed the color difference is just that they are actually
| cooler, so yeah, they cool down quicker. And not just
| "quicker": the difference must be huge in order for it to be
| completely safe to grab the corners and actually dangerous to
| grab the faces. But why?
| blauditore wrote:
| Probably because it cools down much faster there, due to higher
| relative surface (per mass). You can also see this simply by
| the difference in color.
| stevespang wrote:
| Yes, 2nd that, thx for sharing, really cool !
| aezell wrote:
| As a kid, I was involved in NASA's Junior Astronaut program
| around the time of the Challenger disaster. I will never forget
| the presentation where they had us hold one of the heat shield
| tiles in our bare hands while they blasted it with a blowtorch
| for several minutes. It just blew my mind that such a thing was
| possible.
| Supermancho wrote:
| I was fortunate enough to have a presentation, when I was in
| Elementary School (Golden Elementary in Placentia, CA), that
| featured bringing in Shuttle Tiles in the 80s. They put a
| blowtorch to once and let us touch it, right after. It was mildly
| interesting for a 9 year old.
| hinkley wrote:
| Meanwhile, a bunch of my classmates junior year of high school
| took a tour of my future alma mater and came back with stories
| about how the thermite demo went wrong and exploded.
|
| Later I saw black and white video of the same classroom, the
| thermite set the projector screen on fire ( which for some dumb
| reason was down at the time), the instructor panicked and
| pulled the screen causing it to retracted.
|
| This did not put out the fire.
|
| Unfortunately the video cuts out there. The building did not
| burn down, apparently, but I would have liked to have seen the
| full saga.
|
| I almost skipped chemistry class the day they did the thermite
| demo for us. Instead I sat way in the back.
| cronix wrote:
| They came to the schools in Portland, OR, as well and did the
| same blowtorch demo. Loved it.
|
| Came to find out just a few years ago that my aunt, who is
| retired from NSA/CIA/Rand, was one of the people who translated
| the Soviet shuttle plans and helped discover that they were
| stolen from the USA. Apparently she was also involved, somehow,
| in every stealth program up until she retired. Exactly what she
| did...don't know, and she wouldn't elaborate.
| gre wrote:
| I got that demo in Mississippi. They must have had a huge
| outreach program.
| 010101010101 wrote:
| The shuttle main engines were all tested at Stennis Space
| Center in southern MS (the same test stands were used to test
| parts of the Saturn V for the Apollo missions). I got to see
| a bunch of the tests as a kid, it was really something -
| always wanted to see an actual launch, but the closet I've
| come is catching a glimpse of the Falcon 9 from San Francisco
| in 2018.
| tyingq wrote:
| The "don't touch the edges, just the corners" had me a little
| worried. Visitors don't always pay attention. I wonder how hot
| the parts you weren't supposed to touch were.
| Retric wrote:
| Heat is not that important in this context it's energy transfer
| between the block and your skin that's at issue. Holding onto
| the glowing bits may eventually cause burns, but you're
| reflexes are to let go very quickly. My guess is the real risk
| is someone dropping and thus breaking them.
| nickthemagicman wrote:
| What happens to all that heat energy if it's broken?
| dahfizz wrote:
| Most of the cool properties of these aerogel-like materials
| is that they are 90%+ air. Silica also has a relatively low
| specific heat. So, even though the material is very _hot_ ,
| there is not that much heat energy. There is more heat in a
| cup of coffee.
| Retric wrote:
| It gets released more quickly but not insanely so. Like
| spilling a cup of hot coffee, you're increasing the surface
| area.
| labawi wrote:
| Not to mention, there isn't _that_ much heat to speak of.
| At 2200, it should have about as much heat energy vs.
| ambient as a cup of 80 coffee, while being poorly
| conductive.
|
| You could probably set something on fire, but not just
| anything.
| ape4 wrote:
| I know, aren't the corners part of the edges
| tyingq wrote:
| It seems like he meant the central faces of the cubes...the
| glowing parts, to be the "edges". I thought the "edges" were
| the ridge lines.
| [deleted]
| minimuseum wrote:
| This is a great document on how the tiles were made:
| https://ntrs.nasa.gov/search.jsp?R=19810003644
|
| We included fragments of a flown Shuttle tile in our Fourth
| Edition collection. The material is crazy difficult to work with.
| It powders under pressure. You obviously can't use a hot wire to
| cut it either (ha, ha).
| mkchoi212 wrote:
| Why does he say to pick them up by the corners and not by the
| edges? Is there some physics that I'm missing??
| Bud wrote:
| Less surface area that you are touching, and also, you can see
| that the corners are cooler than the rest of the object.
| mkchoi212 wrote:
| Yeah but why do the corners get cooler?
| Aardwolf wrote:
| This is only a guess, but, material in the corners is
| closer to more surface area so loses heat more quickly
| stanmancan wrote:
| More surface area?
| [deleted]
| graphpapa wrote:
| If you think of it like a bunch of cells like minesweeper,
| where the temperature differential is a function of #of
| neighbouring air cells - corners are going to cool much
| faster!
| SoapSeller wrote:
| Veritasium have a nice series[0] about Aerogel - with couple of
| interesting demonstrations and good explanation on how it made.
|
| [0] https://youtu.be/AeJ9q45PfD0
| hnarn wrote:
| > Space Shuttle thermal tiles conduct heat so poorly that (...)
|
| This is nitpicking but it seems odd to use a negative value
| adjective like "poorly" as if high thermal conductivity would
| then be "excellent", instead of just saying something neutral
| like "low heat conductivity". I don't know, it just struck me as
| odd.
| BenjiWiebe wrote:
| It blocks heat well, or conducts heat poorly. Too me the second
| option actually sounds better.
| hnarn wrote:
| To my ears it's kind of like describing a shield as being
| really bad at letting arrows through, but I yield as I seem
| to be outnumbered.
| dzamie wrote:
| It's vernacular, at least. People say copper conducts
| electricity well, so something with low conductivity would
| conduct poorly
| hnarn wrote:
| Sure, but in the case of copper you want to conduct
| electricity, so it makes sense to say that it conducts it
| "well". In the case where you want to avoid head conduction,
| like when re-entering the atmosphere, you don't want heat to
| be conducted, so a "poor" conduction is actually "good". I
| thought it sounded a bit odd, but since I'm being downvoted
| I'm assuming not many people agree, I thought I'd just point
| out that I thought it was interesting and/or caused some
| dissonance for me at least as a reader.
| dwighttk wrote:
| you might not want copper to conduct electricity if it were
| conducting electricity to your body.
| hnarn wrote:
| That's my point. If you're designing a suit that should
| stop yourself from being electrocuted it sounds weird
| saying that copper has "excellent" conductivity, it's not
| really excellent in the context you're talking about.
| dwighttk wrote:
| "Copper has excellent conductivity therefore it wouldn't
| be a great material to make a suit out of if you want to
| stop yourself from being electrocuted... You'd want a
| material that was an excellent insulator!"
| hnarn wrote:
| As I've said, it sounds weird to me but apparently not to
| you so let's leave it at that.
| akeck wrote:
| Also, from the Parker Sun probe:
| https://www.youtube.com/watch?v=BKinVmBoIrE
| rkagerer wrote:
| I agree with the second top comment there:
|
| _The material is fine, this demonstration is hilariously bad.
| This demonstration could be done with a block of wood. Take a
| blow torch to a block of wood that size and pretty much the
| same result._
| hanoz wrote:
| The guide keeps saying it's because they disipate heat so
| quickly, but I thought it was supposed be quite the opposite?
| jansan wrote:
| And also, dissipate to where? To the hotter parts of the
| material? To the air? I think he is wrong.
| balfirevic wrote:
| The outermost part dissipates heat quickly to the air which
| lowers it's temperature (the temperature of the outermost
| part, that is).
|
| In regular materials, the heat flows quickly from the center,
| so the temperature of the outer layer cannot drop
| significantly in such a short amount of time.
|
| But this material conducts heat so poorly that this doesn't
| happen, so the outer layer stays cool.
| jtbayly wrote:
| Fascinating. So it's both: it conducts to air quickly, but
| to itself slowly.
| kragen wrote:
| At these temperatures, radiation is usually a much more
| significant heat transport mechanism than conduction or
| convection, so probably a substantial amount of that heat
| was deposited in the walls of the room and the bystanders.
| javagram wrote:
| Yes, i think the guide is saying it backwards. The caption of
| the video says " Space Shuttle thermal tiles conduct heat so
| poorly that after being in a 2200 degF oven for hours, you can
| pick them up with your bare hands only seconds after they come
| out, still glowing hot"
|
| This makes sense - the tiles themselves are at 2200 degrees but
| are not transmitting the heat quickly to you while you touch
| them for a brief period of time.
| dreamcompiler wrote:
| Yes. Same idea as when you stick your hand into a 400F oven
| to pull the pizza out. Doesn't hurt because air is a poor
| heat conductor. But if you touch the 400F metal pan, it will
| hurt.
| JorgeGT wrote:
| Correct. Similarly, even though space is terribly cold, you
| could be exposed to it briefly without getting cold. Low
| pressure however is the real danger...
| stanmancan wrote:
| Which is also why cooling things down in space is a unique
| challenge. There's nothing to carry the heat away from
| whatever it is you're trying to cool.
| dredmorbius wrote:
| Well, nothing (vacuum) will carry away heat, as radiated
| blackbody radiation. Slowly.
|
| https://en.wikipedia.org/wiki/Thermal_radiation
| 4gotunameagain wrote:
| You're right, these are pure silica tiles, very low density and
| very low heat conductivity.
|
| https://en.wikipedia.org/wiki/LI-900
| [deleted]
| starpilot wrote:
| Yes, they are insulators, so they reduce heat transfer.
| tectonic wrote:
| Self-promotion: if you find this kind of thing cool, check out
| our weekly technical newsletter about the space industry,
| https://orbitalindex.com. We started based on feedback from HN
| about a year ago.
| iscrewyou wrote:
| Finally I found one of you! Thanks for doing this!!
|
| I read the whole thing every time it shows up in my inbox. I
| love that you guys have so many links embedded in each
| newsletter. There are insane amount resources I didn't know
| existed. I love space and you guys are doing a great job
| bringing my childhood curiosity back. Again, thanks!
| MajesticUnicorn wrote:
| This is really cool, thanks sharing this!
| zygy wrote:
| Subscriber for several months, imo one of the few newsletters
| that's actually insight-rich. I learn something new and
| fascinating in each one, thank you for working on it!
| pvaldes wrote:
| Looks like a great material to isolate a house and save heating
| money. Also great for saving air conditioning bills in desertic
| areas. If is just silica, why is not being sold yet? NASA could
| have stored some slighly defective or second grade quality
| blocks, unfit for space shuttle but waiting for a second life.
| jcims wrote:
| https://news.ycombinator.com/item?id=22655398
| dahfizz wrote:
| Producing aerogel is not easy. It's "just silica" in the same
| way that a diamond is "just carbon".
|
| The regular house insulation already works pretty well, and
| heating is not incredibly expensive. Aerogel would have to come
| way down in price for it to make economic sense.
| kragen wrote:
| Space shuttle insulating tiles are not made of aerogel.
| dahfizz wrote:
| Not by that name, but the tiles are made of blocks of
| silica that are 90%+ air, which is the same thing as
| aerogel.
|
| https://en.m.wikipedia.org/wiki/LI-900
| tecleandor wrote:
| Seems like they're still very far in density.
|
| LI-900 is 144.2 kg/m3 (9 lb/ft3) and silica aerogel goes
| around 1,900 g/m3
| mthoms wrote:
| Have a look at (silica) aerogels
| https://en.wikipedia.org/wiki/Aerogel they are in widespread
| commercial use.
|
| As another commenter noted the shuttle tiles are not made of
| aerogel but they _are_ indeed silica based.
| nateburke wrote:
| Corners and edges. Psssshhhhh.
|
| TOUCH THE SIDES!
|
| TOUCH THE SIDES!
|
| TOUCH THE SIDES!
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