Is NASA really testing the Heat Shield Materials?

Putting two astronauts out at the end of the extention on the boom and
having them move around is a test. Models aren't accurate, now they are
calibrated. They were off over 100% in their models.

Doing tile and RCC repair test in the Payload Bay seems is fine and dandy,
but how do the material and techniques hold up under an actual rentry?
Are the models accurate? Do some repair tests to the last tile at the aft
end of the body flag. Calibrate the models. Do bubbles in the goop help or
hurt? Do the fastners hold up? Stick a piece of RCC back there and repair
it.

Has anybody heard if NASA is going to actually test the repair techiques
and materials?

--
Craig Fink
Courtesy E-Mail Welcome @

"Craig Fink" wrote in message
news

Doing tile and RCC repair test in the Payload Bay seems is fine and dandy,
but how do the material and techniques hold up under an actual rentry?
Are the models accurate? Do some repair tests to the last tile at the aft
end of the body flag. Calibrate the models. Do bubbles in the goop help or
hurt? Do the fastners hold up? Stick a piece of RCC back there and repair
it.


Great idea. I have thought that myself. I seem to remember a case back in
the eighties where there was an actually burn thru on either the body flap
or wing flaps. It did not effect anything other then the turn around time
of the shuttle because repairs had to be made. You would think that this
would have been a wake-up call to NASA, but it was just played off as a
non-event.

Eric,

You're thinking of the STS-27R event, I believe. I was just reading
about it
in the CAIB report:

From page 127 of CAIB, section 6.1 A HISTORY OF FOAM ANOMALIES:

One debris strike in particular foreshadows the STS-107 event. When
Atlantis was launched on STS-27R on De-cember 2, 1988, the largest
debris event up to that time significantly damaged the Orbiter.

Mission Commander R.L. "Hoot" Gibson later stated that Atlantis
"looked like it had been blasted by a shotgun."18 Concerned that the
Orbiter's Thermal Protection System had been breached, Gibson or-dered
that the video be transferred to Mission Control so that NASA
engineers could evaluate the damage.

Damage was concentrated outboard of a line right of the bipod
attachment to the liquid oxygen umbilical line. Even more worrisome,
the debris had knocked off a tile, ex-posing the Orbiter's skin to the
heat of re-entry. Post-flight analysis concluded that structural
damage was confined to the exposed cavity left by the missing tile,
which happened to be at the location of a thick aluminum plate
covering an L-band navigation antenna. Were it not for the thick
alumi-num plate, Gibson stated during a presentation to the Board that
a burn-through may have occurred.

=============
EricT wrote:

Great idea. I have thought that myself. I seem to remember a case back in
the eighties where there was an actually burn thru on either the body flap
or wing flaps. It did not effect anything other then the turn around time
of the shuttle because repairs had to be made. You would think that this
would have been a wake-up call to NASA, but it was just played off as a
non-event.

On Tue, 11 Jul 2006 14:44:07 +0000, EricT wrote:


"Craig Fink" wrote in message
news

Doing tile and RCC repair test in the Payload Bay seems is fine and dandy,
but how do the material and techniques hold up under an actual rentry?
Are the models accurate? Do some repair tests to the last tile at the aft
end of the body flag. Calibrate the models. Do bubbles in the goop help or
hurt? Do the fastners hold up? Stick a piece of RCC back there and repair
it.


Great idea. I have thought that myself. I seem to remember a case back in
the eighties where there was an actually burn thru on either the body flap
or wing flaps. It did not effect anything other then the turn around time
of the shuttle because repairs had to be made. You would think that this
would have been a wake-up call to NASA, but it was just played off as a
non-event.

Actually, I believe they have done something similar in the past on STS-1
or STS-2.

A non-event, until the plasma enters the hole.

--
Craig Fink
Courtesy E-Mail Welcome @

On Tue, 11 Jul 2006 07:58:18 -0700, kmmposting wrote:

Eric,

You're thinking of the STS-27R event, I believe. I was just reading
about it
in the CAIB report:

From page 127 of CAIB, section 6.1 A HISTORY OF FOAM ANOMALIES:

One debris strike in particular foreshadows the STS-107 event. When
Atlantis was launched on STS-27R on De-cember 2, 1988, the largest
debris event up to that time significantly damaged the Orbiter.

STS-27, I remember that day, there wasn't any persistence to the
wind.

--
Craig Fink
Courtesy E-Mail Welcome @

Hang on a moment. Taking your analogy to its extreme, one could say that
none of the heat resistant systems were tested when the shuttle first flew,
but I imagine they must have been pretty sure they would work.

I think the only problem may be what happens near the boundary layer
transfer points with a less than smooth surface, but even then I think
enough rough areas have existed so far to know.

Brian

--
Brian Gaff -
Note:- In order to reduce spam, any email without 'Brian Gaff'
in the display name may be lost.
"Craig Fink" wrote in message
news
Putting two astronauts out at the end of the extention on the boom and
having them move around is a test. Models aren't accurate, now they are
calibrated. They were off over 100% in their models.

Doing tile and RCC repair test in the Payload Bay seems is fine and dandy,
but how do the material and techniques hold up under an actual rentry?
Are the models accurate? Do some repair tests to the last tile at the aft
end of the body flag. Calibrate the models. Do bubbles in the goop help or
hurt? Do the fastners hold up? Stick a piece of RCC back there and repair
it.

Has anybody heard if NASA is going to actually test the repair techiques
and materials?

--
Craig Fink
Courtesy E-Mail Welcome @

On Tue, 11 Jul 2006 15:38:40 +0000, Brian Gaff wrote:

Hang on a moment. Taking your analogy to its extreme, one could say that
none of the heat resistant systems were tested when the shuttle first flew,
but I imagine they must have been pretty sure they would work.

When the shuttle first flew, it was tested in the lab but not in the actual
environment. So, yes, they were untested wrt to the actual environment and
the lab tests really needed to be calibrated with real world data.


I think the only problem may be what happens near the boundary layer
transfer points with a less than smooth surface, but even then I think
enough rough areas have existed so far to know.

I think that's just one of the problems. Columbia quite often tripped the
boundary layer early, they probably have lots of data on that. Seems to me
they should be testing all the stuff they are contemplating using for
repair. RCC, goop, coatings, blankets, fasteners ...

Maybe they don't even have the right combination of real world materials
for the repair. Maybe a self-leveling, due to high heat loading, goop
would be better than an ablative that hangs around for a long time
disturbing the airflow.

--
Craig Fink
Courtesy E-Mail Welcome @

Craig Fink wrote:
When the shuttle first flew, it was tested in the lab but not in the actual
environment. So, yes, they were untested wrt to the actual environment and
the lab tests really needed to be calibrated with real world data.

Were the tiles tested using suborbital sounding rockets? That was done for
early heatshields using, if I understand the history books correctly, the
Trailblazer II sounding rocket (which itself was reused Nike boosters).

Glen Overby

Glen Overby wrote:

Craig Fink wrote:
When the shuttle first flew, it was tested in the lab but not in the actual
environment. So, yes, they were untested wrt to the actual environment and
the lab tests really needed to be calibrated with real world data.

Were the tiles tested using suborbital sounding rockets? That was done for
early heatshields using, if I understand the history books correctly, the
Trailblazer II sounding rocket (which itself was reused Nike boosters).

ISTR that Shuttle tiles were tested on the SR-71.

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

Craig Fink wrote in
news
Has anybody heard if NASA is going to actually test the repair
techiques and materials?

Not on an actual entry. They'll test them on sample materials in the
payload bay and subject them to arcjet tests upon return to Earth.

--
JRF

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