Smoking Gun, Now What?

[Gareth Slee]

If NASA are satisfied wing damage caused the tragedy, what do they plan on
doing to avoid a similar incident?

Some means of deflection?
What could possibly be done to protect the shuttle from a similar accident?

--
Gareth Slee

http://www.garethslee.com
http://www.lapie.com

[Jon Berndt]

"Gareth Slee" > wrote in message

> If NASA are satisfied wing damage caused the tragedy, what do they plan on
> doing to avoid a similar incident?
>
> Some means of deflection?
> What could possibly be done to protect the shuttle from a similar
accident?

Some of the possibilities I have heard tossed about are:

1) flying ascent at a smaller (or slightly negative) alpha than they were
at - particularly at higher qbar. The idea is that this would take any
flying debris under and past the orbiter without contact.
2) discussion has already taken place on how to remove the foam-shedding
problem, either by removing the foam from the bipod ramp, or by covering it
with a metal cover.

Perhaps both of these would be done. Does anyone recall from where on the
ET shedding has been seen before? Also, given yesterdays test results, I
wonder if there will be any impetus to design and fabricate new RCC panels.

Jon

[Hallerb]

> Also, given yesterdays test results, I
>wonder if there will be any impetus to design and fabricate new RCC panels.
>
>Jon

Well since you cant elminate foam shedding 100% it would be foolish not to
redesign the RCC.

Heck it means they are terribly vulernable to a minor debris strike too.

[Alan Erskine]

<PLONK>

Fool
--
Alan Erskine
alanerskine(at)optusnet.com.au
With simpathy for the co-joined Iranian twins

"Hallerb" > wrote in message
...
> > Also, given yesterdays test results, I
> >wonder if there will be any impetus to design and fabricate new RCC
panels.
> >
> >Jon
>
> Well since you cant elminate foam shedding 100% it would be foolish not to
> redesign the RCC.
>
> Heck it means they are terribly vulernable to a minor debris strike too.

[Jorge R. Frank]

"Jon Berndt" > wrote in
:

> "Gareth Slee" > wrote in message
>
>> If NASA are satisfied wing damage caused the tragedy, what do they
>> plan on doing to avoid a similar incident?
>>
>> Some means of deflection?
>> What could possibly be done to protect the shuttle from a similar
> accident?
>
> Some of the possibilities I have heard tossed about are:
>
> 1) flying ascent at a smaller (or slightly negative) alpha than they
> were at - particularly at higher qbar. The idea is that this would
> take any flying debris under and past the orbiter without contact.

Any idea what the performance delta would be?

> 2) discussion has already taken place on how to remove the
> foam-shedding problem, either by removing the foam from the bipod
> ramp, or by covering it with a metal cover.

They've actually already made the choice - it will be the former, with
heaters added to prevent ice formation.

> Perhaps both of these would be done. Does anyone recall from where on
> the ET shedding has been seen before?

Besides the bipod ramp, the suspect areas have been the intertank
stringers, the lower intertank flange, and areas on the LO2 tank ogive.

> Also, given yesterdays test
> results, I wonder if there will be any impetus to design and fabricate
> new RCC panels.

It's being studied, but for implementation well after return-to-flight.


--
JRF

Reply-to address spam-proofed - to reply by E-mail,
check "Organization" (I am not assimilated) and
think one step ahead of IBM.

[Greg D. Moore \(Strider\)]

"Raymond Chuang" > wrote in message
...
> "Gareth Slee" > wrote in message
> ...
>
> > If NASA are satisfied wing damage caused the tragedy, what do they plan
on
> > doing to avoid a similar incident?
>
> I see the following changes:
>
> 1. The foam insulation material will go back to the material used before
> they switched to the "environmentally friendly" material that had a
penchant
> to flake off like mad.

The problem is, even the old foam flaked off.

>
> 4. NASA will require _all_ ground tracking cameras be operating during
> shuttle launches.

Fairly likely I'd agree.


>
> --
> Raymond Chuang
> Mountain View, CA USA
>
>

[Hallerb]

>
>> > doing to avoid a similar incident?
>>
>> I see the following changes:
>>
>> 1. The foam insulation material will go back to the material used before
>> they switched to the "environmentally friendly" material that had a
>penchant
>> to flake off like mad.
>
>The problem is, even the old foam flaked off.
>
>>
>> 4. NASA will require _all_ ground tracking cameras be operating during
>> shuttle launches.
>
>Fairly likely I'd agree.
>
>
>>
>> --
>> Raymond Chuang

Its going to have to go beyond this.

Whatever flys again cant be so fragile, and the foam is going to be fixed but
not perfect.

Inspection will not help with a totally smashed panel either.

There a redesign coming just like the challengers O rings solids.

:Likely as long of a delay too.

[Hallerb]

>
>I think just switching to the older foam insulating material will reduce the
>foreign object damage (FOD) problem in the first place. It was

You do realize foam flaking was a problem from day one. Short of some sort of
shield I doubt even using the old stle foam will fix things.

That would be like contiuning to fly after challenger only on warm days.

Whats the rush anyway? True ISS is a problem but other than that a years delay
for redesign is better than another lost vehicle. Espically since as is in
orbit repairs on such a large hole will be duifficult if not impossible.

[Bruce Palmer]

Jon Berndt wrote:

> "Gareth Slee" > wrote in message
>
>
>>If NASA are satisfied wing damage caused the tragedy, what do they plan on
>>doing to avoid a similar incident?
>>
>>Some means of deflection?
>>What could possibly be done to protect the shuttle from a similar
>
> accident?
>
> Some of the possibilities I have heard tossed about are:
>
> 1) flying ascent at a smaller (or slightly negative) alpha than they were
> at - particularly at higher qbar. The idea is that this would take any
> flying debris under and past the orbiter without contact.
> 2) discussion has already taken place on how to remove the foam-shedding
> problem, either by removing the foam from the bipod ramp, or by covering it
> with a metal cover.
>
> Perhaps both of these would be done. Does anyone recall from where on the
> ET shedding has been seen before? Also, given yesterdays test results, I
> wonder if there will be any impetus to design and fabricate new RCC panels.

I'd like to see the latest test repeated using a NEW RCC panel. That
might help answer the question of whether or not age or flight cycles
have any bearing.

--
bp

[Bryan Ashcraft]

"Jon Berndt" > wrote in message
...

> Some of the possibilities I have heard tossed about are:
>
> 1) flying ascent at a smaller (or slightly negative) alpha than they were
> at - particularly at higher qbar. The idea is that this would take any
> flying debris under and past the orbiter without contact.
> 2) discussion has already taken place on how to remove the foam-shedding
> problem, either by removing the foam from the bipod ramp, or by covering
it
> with a metal cover.
>
> Perhaps both of these would be done. Does anyone recall from where on the
> ET shedding has been seen before? Also, given yesterdays test results, I
> wonder if there will be any impetus to design and fabricate new RCC
panels.
>
> Jon

There may be a point with a redesign of the RCC in light of previous foam
shedding on ascent. I saw the video on the first test with the foam being
shot at a orbiter section of RCC panel and was very surprised on how such a
brittle composite vibrated from the impact. Then I saw the pictures with
foam wedged in a RCC joint which surprised me even more. Don't get me wrong
I'll never claim to be a shuttle expert but I thought I would mention my
$0.02 worth. However if the above did take place then a longer standdown
before return to flight would be in order. See link below also mentioning
previous foam losses on ascent.

BA

http://spaceflightnow.com/shuttle/sts107/030408shedding/

[Tom O'Brien]

Gareth Slee wrote:
>
> If NASA are satisfied wing damage caused the tragedy, what do they plan on
> doing to avoid a similar incident?
>
> Some means of deflection?
> What could possibly be done to protect the shuttle from a similar accident?

Two things I've been wondering about...

1: why is the insulation on the outside of the tank? It seems to me
that all the outside surfaces should be capable of bearing considerable
loads.(my only answer to this is the weight savings from having the
metal parts of the tank 10 inches further inboard, which I'd guesstimate
at several hundred-several thousand pounds)

2: (this probably sounds stupid to anyone who knows anything): Is the
external insulation necessary during the actual launch process? i.e.,
is it there to keep the hydrogen from boiling during countdown, or is it
there to prevent the boiling during the ascent? If it's the prior case,
could the insulation be shed on the ground through some mechanical means
during the final minutes/seconds?

TO

[Jon Berndt]

"Jorge R. Frank" > wrote in message

> "Jon Berndt" > wrote in
>
> > 1) flying ascent at a smaller (or slightly negative) alpha than they
> > were at - particularly at higher qbar. The idea is that this would
> > take any flying debris under and past the orbiter without contact.
>
> Any idea what the performance delta would be?

Don't know. Perhaps they would loft slightly just prior to the lower-alpha
phase ... more vertical intial kick angle? Not sure. I've a hunch the
performance change would be small, though.

Jon

[Doug...]

In article >, says...
> Charleston wrote:
>
> > "Tom O'Brien" > wrote in message
>
> >>1: why is the insulation on the outside of the tank?
>
> [ various reasons ]
>
> Organic foam soaked in LOX is also probably not something you want.

And, to be fair, the Saturn S-II stage had internal insulation if I'm
remembering correctly (though not a foam type), and it still generated a
lot of ice on the external surface of the stage. The external insulation
on the ET is there primarily to stop ice formation (since falling ice
would damage the orbiter), so I would think you would have to come up
with a far different insulation scheme to use internal insulation.

--

It's not the pace of life I mind; | Doug Van Dorn
it's the sudden stop at the end... |

[jeff findley]

Doug... > writes:
>
> And, to be fair, the Saturn S-II stage had internal insulation if I'm
> remembering correctly (though not a foam type), and it still generated a
> lot of ice on the external surface of the stage. The external insulation
> on the ET is there primarily to stop ice formation (since falling ice
> would damage the orbiter), so I would think you would have to come up
> with a far different insulation scheme to use internal insulation.

It's also been noted that the ET uses external insulation so the
aluminum structure stays cold. Aluminum's strength is more at the
colder temperatures than if it were on the outside, subject to both
hot Florida days and aerodynamic heating upon launch.

Jeff
--
Remove "no" and "spam" from email address to reply.
If it says "This is not spam!", it's surely a lie.

[Eric Pederson]

"Doug..." wrote:
>
> In article >, says...
> > Charleston wrote:
> >
> > > "Tom O'Brien" > wrote in message
> >
> > >>1: why is the insulation on the outside of the tank?
> >
> > [ various reasons ]
> >
> > Organic foam soaked in LOX is also probably not something you want.
>
> And, to be fair, the Saturn S-II stage had internal insulation if I'm
> remembering correctly (though not a foam type), and it still generated a
> lot of ice on the external surface of the stage. The external insulation
> on the ET is there primarily to stop ice formation (since falling ice
> would damage the orbiter), so I would think you would have to come up
> with a far different insulation scheme to use internal insulation.
>
> --

IIRC it was the S-IV and only on the H2 tank. The description
from one of the NASA historial documents was of syntactic foam
(resin and microballoons) blocks carved to fit between the orthogrid
blades inside the tank hand bonded inplace one-by-one. IIRC the
S-II H2 tank had external insulation to reduce boiloff and was the
basis for the shuttle ET.