Cavity behind the RCC leading edge

When I looked at the video of how they simulated the foam block
colliding with the reinforced carbon carbon leading edge of the
shuttle, I noticed that behind the leading edge (which is a thin sheet
of RCC) there was nothing.

Isn't this highly irresponsible, in other words stupid? Any
homebuilder of kit airplanes knows that filling the cavity with foam
would greatly enhance the strength of the leading edge without
increasing the weight of the structure. The carbon fibers comprising
the composite sheet are strong in tension/compression but can be bent.
This lack of support from the inside was the direct cause of the hole
that the foam block punched in it.

Zoltan

On Thu, 28 Aug 2003 23:43:41 +0100, Doug Ellison wrote:

Genuine thought process I once had

"That aerogel stuff looks really cool. They should make an office toy out of
it. A paperweight or something"

LMFAO - a PAPERWEIGHT!!

Sure... about 10-15 cubic meters worth should be beyond the
capacity of the average office air conditioning vent to move.
Just don't breath on it or you'll never find out where it went...



Say "Ah"

:P

You need your tonsils out... again.



Still - they SHOULD make an office toy out of it :P

An aerogel desk?...

Doug

--
Chuck Stewart
"Anime-style catgirls: Threat? Menace? Or just studying algebra?"

"Zoltan Szakaly" wrote in message
om...
Any
homebuilder of kit airplanes knows that filling the cavity with foam
would greatly enhance the strength of the leading edge without
increasing the weight of the structure.

Really? You could fill all that space with foam with zero mass?

Doug

Doug Ellison wrote:

Really? You could fill all that space with foam with zero mass?

Foam that would tolerate being in contact with white-hot RCC
material, no less.

Paul

"Paul F. Dietz" wrote in message
...
Doug Ellison wrote:

Really? You could fill all that space with foam with zero mass?

Foam that would tolerate being in contact with white-hot RCC
material, no less.

Forgot that bit

Foam that has zero mass, enormous heat resistance, is flight qualified, will
not outgas on orbit, and will make you coffee in the morning

Doug

In message , Chuck Stewart
writes
On Thu, 28 Aug 2003 21:23:37 +0100, Doug Ellison wrote:

"Paul F. Dietz" wrote in message
...
Doug Ellison wrote:

Really? You could fill all that space with foam with zero mass?

Foam that would tolerate being in contact with white-hot RCC
material, no less.

Forgot that bit

Foam that has zero mass, enormous heat resistance, is flight qualified, will
not outgas on orbit, and will make you coffee in the morning

Aha!

Aerogel!

Aerogel just like those used in insulating blocks on the Mars
Sojourner Rover!

Aerogel stripped from a Rover is ust the ticket... aerogel filler
will have next-to-zero mass, heat resistance, is flight qualified,
will not outgas on orbit, and the Rover can make you coffee in the
morning.

Structural strength?
--
"Forty millions of miles it was from us, more than forty millions of miles of
void"

"Chuck Stewart" wrote in message
news
On Thu, 28 Aug 2003 21:23:37 +0100, Doug Ellison wrote:

"Paul F. Dietz" wrote in message
...
Doug Ellison wrote:

Really? You could fill all that space with foam with zero mass?

Foam that would tolerate being in contact with white-hot RCC
material, no less.

Forgot that bit

Foam that has zero mass, enormous heat resistance, is flight qualified,
will
not outgas on orbit, and will make you coffee in the morning

Aha!

Aerogel!

Aerogel just like those used in insulating blocks on the Mars
Sojourner Rover!

Aerogel stripped from a Rover is ust the ticket... aerogel filler
will have next-to-zero mass, heat resistance, is flight qualified,
will not outgas on orbit, and the Rover can make you coffee in the
morning.

Problem solved...


Genuine thought process I once had

"That aerogel stuff looks really cool. They should make an office toy out of
it. A paperweight or something"

LMFAO - a PAPERWEIGHT!!

:P

Still - they SHOULD make an office toy out of it :P

Doug

(Zoltan Szakaly) wrote
When I looked at the video of how they simulated the foam block
colliding with the reinforced carbon carbon leading edge of the
shuttle, I noticed that behind the leading edge (which is a thin sheet
of RCC) there was nothing.

I thought this was odd, too. I'm surprised what with the woodpeckers
pecking holes in the foam that they didn't get birds building nests in
there or mice building habitrails. I wonder if they ever stuck a
flashlight up there to check.

On Thu, 28 Aug 2003 19:32:07 +0000, Zoltan Szakaly wrote:

From reading the responses here it sounds like you guys are the same
ones that designed the leading edge without the foam filling.

You leapfrog to a conclusion over the back of a non-sequitur...

The "foam inside leading edge" idea is a thought, and not a really
bad one, but your approach was way off-base.

To quote you:

"When I looked at the video of how they simulated the foam block
colliding with the reinforced carbon carbon leading edge of the
shuttle, I noticed that behind the leading edge (which is a thin sheet
of RCC) there was nothing.

So far so good, but then you follow with:

"Isn't this highly irresponsible, in other words stupid?"

Not so good. You seem to assume that you already know the answer...
and you don't. Posters here do not tend to react warmly to even
unintentional arrogance anymore.

Practically the foam would have no appretiable weight so that
point is mute.

The only "foam" in existence that meets even a few of the criteria
neccessary for your requirements is aerogel, which would add no
structural strength to the wing, and which _would_ conduct heat.

The foam inside would not be exposed to the heat of the outside.

Yes, it would. THe RCC gets HOT. And any "foam" behind it would
conduct the heat even faster than the void that is currently behind
the leading edges.

The purpose of the RCC is stand out there and take punishment the
tiles would take... while providing the hard, smooth aerodynamic
surface the tiles _can't_ provide.

As for flight qualifying the foam thats a ridiculous burocrat's
statement.

Er... no. Your ignorant arrogance is showing again.

Flight qualification for the orbiter encompasses the ability to
survive entire realms each of highly varied conditions.. and the
transitions bewtween those realms.

The orbiters structure meets criteria that would have been
diffilcult-to-impossible to meet any other way... at the time of
its design.

Damn all little in the aerospace industry meets those criteria
even today.

All kinds of airplanes are made using composits and there are
fire resistant foams in common use.

My original point stands.

Er... no. It's still down for the count. Sorry.

Zoltan

--
Chuck Stewart
"Anime-style catgirls: Threat? Menace? Or just studying algebra?"

On Thu, 28 Aug 2003 22:40:56 +0000, JazzMan wrote:

Doug... wrote:

If you fill up the space behind the RCC panels with foam or anything else
that can conduct heat, that material will get really hot, really fast.
And it will conduct the heat into the interior of the wing. This is
exactly what you're trying to prevent.

It seems to me that another leading edge breach is inevitable,

?
Do you regard it as completely impoosible to prevent?

and unless there is a way to mitigate the effects of heat entering the
wing structure, another loss of ship and crew is guaranteed.

Repair and inspection is not an option?

Reentry heating seems to be one of the most, if not the most,
important element in an operational cycle of the shuttle.

Important = hazardous?
If so, then launch is right up there with it.

vaguely remember reading something about aerogel in the past, but
it seems to me I remember it having an extremely low thermal
conductivity, perhaps even less than the shuttle tiles.

Aerogel is the shuttle tile concept taken orders of magnitude
further... a little silica... a lot of air... "Solid Smoke".

If that were the case, and given the low mass, filling the
leading edge cavity might buy enough time for the ship to
transition through the superheating phase of reentry and get the
ship and crew home.

No. Aerogel's insulating properties start to shine when there's an
ambient atmosphere to be entrained within it. You'd just be
stuffing the leading edge wing voids with silica strands able to
conduct heat into the wing interior... something that the designers
went to a lot of trouble to avoid.

Another thought: What would happen if the part of the aluminum
wing structure that faces that cavity were to be lined with
shuttle tiles?

I dunno

Would tiles inside prevent the RCC breach from "zippering" the wing
anyway? Probably not.

Would it add a couple of hundred pounds to the weight of the
structure? So what if it did?

Might work... if the RCC breach doesn't destroy the ship anyway.

Even with the capacity reduced that much the Shuttle is still
the heaviest lift capable ship currently operating in the world.

I thought the new heavies were going to solve that... haven't
looked at them closely, yet.

Just thinking out loud...

Sure

JazzMan

--
Chuck Stewart
"Anime-style catgirls: Threat? Menace? Or just studying algebra?"