Observation on TPS damage on Orbiter

NASA photos | 2-3-03 | BoneMccoy

[bonesmccoy]

In recent days the popular media has been focusing their attention on an impact event during the launch of STS-107. The impact of External Tank insulation and/or ice with the Orbiter during ascent was initially judged by NASA to be unlikely to cause loss of the vehicle. Obviously, loss of the integrity of the orbiter Thermal Protection System occured in some manner. When Freepers posted the reports of these impacts on the site, I initially discounted the hypothesis. Orbiters had sustained multiple impacts in the past. However, the size of the plume in the last photo gives me pause.

I'd like to offer to FR a few observations on the photos.

1. In this image an object approximately 2-3 feet appears to be between the orbiter and the ET.

2. In this image the object appears to have rotated relative to both the camera and the orbiter. The change in image luminosity could also be due to a change in reflected light from the object. Nevertheless, it suggests that the object is tumbling and nearing the orbiter's leading edge.

It occurs to me that one may be able to estimate the size of the object and make an educated guess regarding the possible mass of the object. Using the data in the video, one can calculate the relative velocity of the object to the orbiter wing. Creating a test scenario is then possible. One can manufacture a test article and fire ET insulation at the right velocity to evaluate impact damage on the test article.

OV-101's port wing could be used as a test stand with RCC and tile attached to mimic the OV-102 design.

The color of the object seems inconsistent with ET insulation. One can judge the ET color by looking at the ET in the still frame. The color of the object seems more consistent with ice or ice covered ET insulation. Even when accounting for variant color hue/saturation in the video, the object clearly has a different color characteristic from ET insulation. If it is ice laden insulation, the mass of the object would be significantly different from ET insulation alone. Since the velocity of the object is constant in a comparison equation, estimating the mass of the object becomes paramount to understanding the kinetic energy involved in the impact with the TPS.

3. In this image the debris impact creates a plume. My observation is that if the plume was composed primarily of ET insulation, the plume should have the color characteristics of ET insulation. This plume has a white color.

Unfortunately, ET insulation is orange/brown in color.

In addition, if the relative density of the ET insulation is known, one can quantify the colorimetric properties of the plume to disintegrating ET insulation upon impact.

Using the test article experiment model, engineers should fire at the same velocity an estimated mass of ET insulation (similar to the object seen in the still frame) at the test article. The plume should be measured colorimetrically. By comparing this experimental plume to the photographic evidence from the launch, one may be able to quantify the amount of ET insulation in the photograph above.

4. In this photo, the plume spreads from the aft of the orbiter's port wing. This plume does not appear to be the color of ET insulation. It appears to be white.

This white color could be the color of ice particles at high altitude.

On the other hand, the composition of TPS tiles under the orbiter wings is primarily a low-density silica.

In the photo above, you can see a cross section of orbiter TPS tile. The black color of the tile is merely a coating. The interior of the tile is a white, low-density, silica ceramic.

[Cold Heat]

How much "income" was derived from those experiments on this flight ?"

I would expect them to commercialize this venture more than this.

Or do you want the entire future space program on a goobermint nickle?

If so, we will never get beyond making smoke signals, as we are today.

[XBob]

very interesting picture ws.

look at the spots on the ohms pod tiles. each spot is where something hit the tiles, either in this or some previous mission. the dark 'spots', particularly those on the left (right in picture) ohms pod are most likely new gouge damages. and the tiles on the ohms pods generally stay on really well (they are in a protected heat 'shadow' area on return)

[XBob]

to "each spot is where something hit the tiles, ",

add:

or where water penetrated and stained the tilea

[Cold Heat]

Yes, the recent reports,(some that you have posted), indicate that NASA was having hell with debris strikes of unknown origin.

As you know, I do not by the foam theory, but I have mentioned micro meteorites.

We recently passed through that belt of small ice particles that gave us such a show on the ground,(I watched it at about 1AM one night.

This fact and a world of trash out there is what gave me the inspiration to say the words"Act of God"

It is well within the realm of possibility that they hit something and holed the wing.

[XBob]

This is tooo funny. Toilet paper, a luxury?

You better believe it, in a lot of countries. and even when available, the quality is often very poor, varying from wax paper, to cardboard, to tissue paper, to some which feels like sand paper.

[Cold Heat]

or where water penetrated and stained the tilea

I believe the procedure is to patch and replace only when necessary.

A waterproofing substance is sprayed on the craft at turnaround after repairs.

[XBob]

327 - "What that changes is the angle when striking the wing. As was noted earlier, there appears to be a second object flapping around as well that dissappears. It seems to me that the strike may have been slower, but more perpendicualr than the first pictures suggested. That would make it more penetrating, but damaging over a much smaller area...though as for specific effects, I couldn't say."

very interesting. "more perpendicular" - perhaps more gouging.

and yes, the second piece flapping around and disappearing, I wonder, if it was ice and the other insulation, and the ice just went into vapor? as it is clearly visible, then gone.

[XBob]

328 "that there is a clear picture of the underside of the shuttle taken by a long range camera (unknown location to me) that showes "signifacant damage" to the wing."

ABC had that on Good Morning America, and Dianne Sawyer had a shuttle model, and seemed to point to the area of insulation impact, as the area where damage was observed, the left wheel well, next to the fuselage.

they did not show the picture.

[XBob]

I am looking for a link to the video from cal/ariz/nm where it appears that the shuttle is dropping flares, a couple tiny, then one big one.

Does anyone have a link?

[XBob]

sorry too - I'm having my first coffee.

but I really think it is the TPS system fault. There are so many things which are being monitored, all over the shuttle, that IMO any failure (such as an APU blowing up or a computer failing) would be immediately known. Only the TPS system has lots of places where it is not monitored, and the accident began just when the tps system was being stressed the most. And we saw pieces pop off (the flares over california), and there is no mention of anything not working at that time, yet it is losing pieces. but it is still flying, and flying pretty well, and there is no comment about any great problems at the time of the 'flares' in anything I have seen. then the landing gear temperature sensors quit. then later, minutes later, it lost control and started breaking up.

I still think it's tps, no matter what NASA says at this time.

but at the very end, it could be a computer/rcs/elevon problem, in attempting to correct for the tps drag, lost it, causing the final destruction.

[Cold Heat]

I have the stills, but my pic program won't open them. I will need to find a patch. I have not seen the video on the net, but it must be somewhere.

[XBob]

Regarding 336, I believe other debris is the operative word here.

the opertive words here are that damage to 1 critical tile in the wrong place at the wrong time will destroy the whole shuttle. not all tiles are created equal, nor are they of equal criticality.

one bullet in the foot will damage you. 1 bullet in the heart will kill you.

[Cold Heat]

but I really think it is the TPS system fault

We are in total agreement that the heat protection system failed. I have no arguement.

The cause of the failure is where we differ.

You are seeing that foam gouging out enough tile at the right spot to start the senario.

I see another cause because I just can't see the foam doing it or at least not enough evidence to prove that it did.

Those pic(slightly out of focus) that were shown by NASA on the second or third day were telling becuse they showed the bottom of the wing and there was no white streak or patch.

I also see the foam hitting more to the mid wing.

[XBob]

we will never get beyond making smoke signals, as we are today.

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we need to spend our money on anti-gravity research, rather than wasting it on Chanel #5 research.

[CCWoody]

Sure, I'll be more specific. Even if you are able to estimate the relative kenetic energy between the insulation and the left wing, you still haven't determined the impact energy or the transfered energy. Chew on that for a while and see if you can figue out why that is so.

[XBob]

It is well within the realm of possibility that they hit something and holed the wing.

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ALL RIGHT, YOU WIN - GOD DID IT.

[XBob]

I believe the procedure is to patch and replace only when necessary.

A waterproofing substance is sprayed on the craft at turnaround after repairs.

true - and it is necessary to do it on each flight. Remember, the Colombia flew back from Edwards in California, and sometimes hit some rain storms.

it was the 'dirtiest' of the birds, which is why i pointed out the dark spots, apparently new.

[Cold Heat]

Unknown tubulances and no idea of how the foam impacted the surface. How much surface area involved and the density of the foam. Al these factors are as yet unknown.

The impact force is measured as if the foam were a unbreakable solid. It is not and it absorbed the impact to a degree. That must be factored in to figure the anticipated damage.

[XBob]

I have the stills, but my pic program won't open them.

what format are they?

[Cold Heat]

GOD DID IT.

LOL That is no fair!

I did not intend to name drop the big guy!