
Picking up glowing hot space shuttle tiles with bare hands (2011) [video] - mpweiher
https://kottke.org/20/03/picking-up-glowing-hot-space-shuttle-tiles-with-bare-hands
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tectonic
Self-promotion: if you find this kind of thing cool, check out our weekly
technical newsletter about the space industry,
[https://orbitalindex.com](https://orbitalindex.com). We started based on
feedback from HN about a year ago.

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zlsa
I've been subscribed since nearly the beginning, and always take the time to
read through the entire email. Thanks for creating (and maintaining) it!

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tectonic
Thanks :)

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Supermancho
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.

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hinkley
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.

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Taniwha
A teacher at my highschool did the thermite demo over a large ceramic dish, it
shattered the liquid iron blob burned through the floor into the classroom
below

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Hallucinaut
I have to ask, given your user name, was this in central-west Auckland in the
mid-90s by any chance?

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hanoz
The guide keeps saying it's because they disipate heat so quickly, but I
thought it was supposed be quite the opposite?

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javagram
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
°F 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.

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JorgeGT
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...

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stanmancan
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.

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rrauenza
And a large aspect of the game Oxygen Not Included! Makes it even harder they
don't model radiative heating..

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minimuseum
This is a great document on how the tiles were made:
[https://ntrs.nasa.gov/search.jsp?R=19810003644](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).

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aezell
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.

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pvaldes
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.

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dahfizz
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.

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DonHopkins
It's 2020, aren't we supposed to have Aerogel-Wiz in a can, and quick-dry
spray-on Velcro in two cans: hooks and loops?

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jacquesm
Hm... I can think of a way to spray the hooks, I don't think I can figure out
how to spray loops. If you figure out the loop part we're in business.

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DonHopkins
I'm still trying to figure out how to manufacture enormous quantities of
lighter-than-air SEAgel in different flavors and colors, to solve the world's
hunger and food delivery problems in one swoop. Edible SEAgel blimp drones!

[https://www.youtube.com/watch?v=HoCAxS4vqwQ](https://www.youtube.com/watch?v=HoCAxS4vqwQ)

[https://en.wikipedia.org/wiki/SEAgel](https://en.wikipedia.org/wiki/SEAgel)

>SEAgel (Safe Emulsion Agar gel) is one of a class of high-tech foam materials
known as aerogels. It is an excellent thermal insulator and among the least
dense solids known. SEAgel was invented by Robert Morrison at the Lawrence
Livermore National Laboratory in 1992. SEAgel is made of agar, a carbohydrate
material that comes from kelp and red algae, and has a density of 200 mg/cm3.
SEAgel can be made lighter than air using hydrogen, causing it to float or
hang in the air. It insulates against temperature, noise, and electric
current. SEAgel is also completely biodegradable, as it is made entirely of
biological material and can even be eaten.

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jacquesm
Neat. I've played around a bit with a kit of different densities of aerogel
made by Philips, crazy material properties, especially on the less dense end
of the spectrum. The lightest was something like 3% glass by volume, eerie
stuff.

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DonHopkins
You can order Aeroeggs today, but they are not edible and do not autonomously
ship themselves to you by air.

[http://www.buyaerogel.com/product/aeroeggs/](http://www.buyaerogel.com/product/aeroeggs/)

>Aeroeggs from Aerogelex are unique aerogels made from hard-boiled eggs. While
many people think of space-age blue holographic solids made of silica when
they hear the word aerogel, aerogels can actually be made from a wide variety
of substances including biopolymers such as those found in eggs. Aeroeggs are
made through supercritical drying, the same process used to make other
aerogels, just using boiled eggs instead of silica or polymer gel precursors.
Boiling an egg causes the proteins in the egg to denature and link together to
form a gel matrix that contains water in its pores. Once the inside of the egg
has congealed, the shell is removed and the boiled egg inside is soaked in
ethanol to replace the water in its pores with a non-polar solvent that is
compatible with supercritical drying. After soaking the egg is put in a high-
pressure vessel and the ethanol in its pores is extracted with supercritical
carbon dioxide to make an egg aerogel.

>Aeroeggs are made from ordinary chicken eggs but are about half the size of a
typical hard boiled egg due to contraction of the egg protein network when the
water in the egg is replaced with ethanol and carbon dioxide. Density is
approximately 0.6 g/cc making Aeroeggs approximately 50% air by volume.
Aeroeggs absorb 3x their weight in water to irreversibly rehydrate back into
regular hard boiled eggs.

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jacquesm
Very cool :) That SEAGel sounds like great stuff to make model aircraft from.
Light enough to power with solar cell and tiny motor.

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DonHopkins
You could make edible Donut Blimps!

[https://www.youtube.com/watch?v=TepADUdDEVg](https://www.youtube.com/watch?v=TepADUdDEVg)

[https://www.youtube.com/watch?v=2oZUEzRFlT0](https://www.youtube.com/watch?v=2oZUEzRFlT0)

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SoapSeller
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](https://youtu.be/AeJ9q45PfD0)

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tyingq
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.

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Retric
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.

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nickthemagicman
What happens to all that heat energy if it's broken?

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dahfizz
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.

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derekp7
I guess this is similar to pulling out a sheet of aluminum foil from a hot
oven. It is weird that you can grab it with your bare hands.

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akeck
Also, from the Parker Sun probe:
[https://www.youtube.com/watch?v=BKinVmBoIrE](https://www.youtube.com/watch?v=BKinVmBoIrE)

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rkagerer
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._

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pvaldes
(I wonder if this ultraporous stuff could be used to make a emergency mask. It
seems clear that is not easy to work with, but... Looks like a giant filter
for a machine)

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mkchoi212
Why does he say to pick them up by the corners and not by the edges? Is there
some physics that I'm missing??

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Bud
Less surface area that you are touching, and also, you can see that the
corners are cooler than the rest of the object.

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mkchoi212
Yeah but why do the corners get cooler?

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graphpapa
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!

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krick
Why can you grab it only on the corners?

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chki
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?

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krick
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?

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nateburke
Corners and edges. Psssshhhhh.

TOUCH THE SIDES!

TOUCH THE SIDES!

TOUCH THE SIDES!

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hnarn
> 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.

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dzamie
It's vernacular, at least. People say copper conducts electricity well, so
something with low conductivity would conduct poorly

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hnarn
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.

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dwighttk
you might not want copper to conduct electricity if it were conducting
electricity to your body.

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hnarn
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.

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dwighttk
"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!"

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hnarn
As I've said, it sounds weird to me but apparently not to you so let's leave
it at that.

