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.

[XBob]

see link above - ROTFLMAO -


"In his afternoon briefing, Dittemore presented charts showing the sequential shutdown of sensors during the final minutes of Columbia's flight as the orbiter encountered a problem as yet undefined. He also revealed a fuzzy photo taken by Air Force cameras as Columbia flew overhead. Dittemore discounted earlier press reports, which interpreted the damage, as premature. He said,

" It is not clear to me that this photo reveals anything significant at this point."

[XBob]

ROTFLMAO

"It does not make sense that a piece of (foam) debris caused the loss of Columbia and its crew," Dittemore added.


http://spaceflight.nasa.gov/spacenews/reports/sts-107/sts-107-23.html

[XBob]

Kostelnik reported that larger and denser pieces of debris have been found in Louisiana, possibly including parts of Columbia's main engines.

http://spaceflight.nasa.gov/spacenews/reports/sts-107/sts-107-23.html

[Eastbound]

Heres the link to the video showing the northern Arizona video taken by the two kids showing something separating from the shuttle at 7:55:52 Dallas Time (time/date stamp on video was 6:55:52): CLICK!

Video also shows another clip of contrail anomolies occuring in California a few minutes earlier.

[Budge]

That is a sizable chunck of carbon/carbon.

Don't you think that wing parts found in the Dallas/Ft. Worth area more than likely would be from the right wing? It would seem any left wing parts would be further west.

[Budge]

because you must still hoist the protection gear off the pad.

True. I suppose any material strong enough to protect the tiles would weigh too much to counter the safety. Anything light and/or thin would be a waste of time, effort, and money.

[freepersup]

" It is not clear to me that this photo reveals anything significant at this point."

Other than a teeny weeny event where the leading edge of the left wing has deformed and the ship is coming apart as it roars across the sky on fire-

[freepersup]

Roger that- Thanks for the time hacks.

I look forward to the story board that NASA is sure to create, what with all of the amateur and professional documentation available to them.

Hours, minutes, seconds, superimposed on a screen- click- images running- click- sensor indications displayed- click- flight position over the U S- click- vehicle condition- click... etc.

[freepersup]

I understand risk is inherent in such an endeavor as space flight / exploration. Therefore, the inherent risks associated with the tile technology may in fact be an acceptable risk. After all, what we've just witnessed are the first fatalities in the shuttle program to be associated with such risks.

It's possible that the next 200 launches go off without a hitch, before another tile strike and burn through takes place. Perhaps another 1,000 launches go off without a hitch. Or... Murphy's law rears it's ugly head and the next launch sees a piercing of the underside of the wing.

In my lay mind I probably can't even begin to fathom the enormous difficulties and complexities that would go into re-engineering the tile design- ie: 'armor' plating.

I know the trade off is weight gain vs protection...

However, I want (my-our) engineers to work this problem out to completion-operation (in theory).

What is the story behind Russia's space launch system ? Even as a lay person I've heard the buzz or hype, that these rockets are monsters and out lift our system significantly.

Need ceramic tile protection ? Plate them. Too much weight ? Increase the lifting power. Don't we need to look at increasing our lift system / capabilities anyway ?

The shuttle hasn't come close to projected launch schedules and is grossly off the charts regarding financial budgets.

Maybe we should take a real hard look at these shortcomings ? Perhaps the silver lining in this cloud might be that NASA is turned on it's proverbial head and shook vigorously.

With some vision (Mars, deep space, heavier loads, robust schedule) we might end up with a far better (more powerful) launch system and a safer shuttle. One that sprang from the more immediate problem at hand, improvement of the tile technology with emphasis on protecting / strengthening said tiles ?

So we protect the tiles with plating (super heat resistant metals alloys ? ) and wind up with a far better lift capability.

THINK BIG- we have to think anyway. paraphrasing (I think) Donald Trump

[Cold Heat]

perhaps nearly the whole leading edge of the wing stripped off, when the front part pulled off.

Yes, if the impact point we selected is correct, the plasma could have undermined the structure holding the edge pieces on.

As stated somewhere earlier, the assembly is fastened to the shuttle wing about two feet back from the edge.

In my travels and career I have used a plasma cutter on numerous occasions. They cut metal faster than a oxy-acetylene torch. The plasma blows the hot debris out of the way and hungers for more. It is very fast once you get it going and cuts almost anything, especially stainless and aluminum alloys.

[Thud]

Long useful thread.

[Thud]

I agree with the first part of your secondary theory. IMO the tile-shedding began at the trailing edge. I'm still uncertain as to whether the final loss of control was due to increasing port drag eventually overpowering the ability of the control mechanisms to maintain stability, or there was a final catastrophic event causing loss of control - mostly likely an elvon burn-through.

[Thud]

That's the way I see it.

[Cold Heat]

http://spaceflightnow.com/shuttle/sts107/030207avweek/

[Cold Heat]

IMO the tile-shedding began at the trailing edge.

Actually, we believe it began at the wheel well door area,(left side), and progressed from there, once the door failed.

[Cold Heat]

This means that in addition to the possible failure of black tile at the point where the wing joins the fuselage, a failure involving the attachment mechanisms for the leading edge sections could also be a factor, either related or not to the debris impact. The actual front structure of a shuttle wing is flat. To provide aerodynamic shape and heat protection, each wing is fitted with 22 U-shaped reinforced carbon-carbon (RCC) leading-edge structures. The carbon material in the leading edge, as well as the orbiter nose cap, is designed to protect the shuttle from temperatures above 2,300F during reentry. Any breach of this leading-edge material would have catastrophic consequences.

This is a excerpt from the above article.

[freepersup]

What I find intriguing in all of the sensor data (6 minutes 19 seconds) is the slightly off normal temperature gains. Nothing drastic.

Puzzling, in that, all data is lost in the 6th minute and 20th second. Like snapping your finger or flipping a light switch. Poof- The cataclysmic event occurring at this moment is total.

How many like events do we have data on (to reference) where an airship that is traveling at 12,000 mph, disintegrates ? If we are to compare apples with apples then the obvious answer is none (only shuttle accident on re-entry).

It's hard to come to grips with having all data functioning and transferring as normal, to a slight anomaly in readings, to absolutely nothing... which means we no longer have an intact ship or crew.

[Spunky]

Wow! Thanks for the video link.

[freepersup]

"Total destruction with little warning or data. Tiles peeling off fit this profile. A fatal action was unfolding in slow motion which reached critical mass with catastrophic consequences."

[Spunky]

What I find intriguing in all of the sensor data (6 minutes 19 seconds) is the slightly off normal temperature gains. Nothing drastic.

Puzzling, in that, all data is lost in the 6th minute and 20th second. Like snapping your finger or flipping a light switch. Poof- The cataclysmic event occurring at this moment is total.

According to the tape the captain and ground control was talking about the temp. raise and the captain was cut off right in the middle of a word.

Which shows how cataclysmic it must have been.