[bonesmccoy]

Based upon the volume, size, and color of the plume; one wonders if the plume in the last frame has significant amounts of tile silica and only minimal amounts of insulation or ice. This would give the relatively large amount of white plume for such a small object.

Another freeper noted that the orientation of the insulation/ice object changes the impact force based upon the surface area of the impact. The individual made the observation that if the object had impacted "edge" on, the damage would be greater than if the object impacted flatly on the leading edge.

The white plume seen in this frame may be partly composed of silica particles from pulverized tiles. Given the substantial size of the plume when compared to the relatively small size of the object, one wonders if the plume size is actually the density and size one would expect from an insulation approximately 2 feet in diameter.

Once it is established that ET insulation alone can not create the plume seen (via the colorimetric test), it should be possible to create a second test scenario. A mixture of ice and ET insulation can be created to mimic estimated launch conditions. That mixture should be fired at the test article and the plume colorimetrics studied.

The resulting data could be compared to the photographic evidence and permit the composition of the plume to be evaluated in a scientific manner.

It is my contention that if one compares the plume from a 2' piece of ET insulation to the plume in the photo: 1. The photo has a plume with greater white tones 2. The photo has a plume in greater size than expected. 3. The differences in size of plume and tone are accounted for by silica pulverized by the impact.

Knowing hindsight is always 20/20, I welcome discussion and criticism. This posting is meant to contribute to the scientific process and only suggests one scientific method to approach the accident investigation.

Thanks... God bless and rest the crew of STS-107 and 51-L.

[Mo1]

BTT for a later read ..

[Cold Heat]

Interesting.

I wonder though, whether or if ice was invoved, would the plume not have some prismatic effect as light reflected off of it?

[neutrino]

Impressive analysis!

[Lion's Cub]

I'm not a scientist and probably shouldn't speak up, but I'm wondering if the colors you are relying on are due simply to the highlighting?

In all photos but that above point 4, the ET has a reddish-looking thing near the bottom of the picture. The highlighting does not occur in this area.

In the picture above point 4, where the highlighter does cover that area, the previously reddish-looking thing is now white, yet the plume does not appear to have extended far enough to have produced that white color.

I'm neither disputing nor defending the tile theory because I simply don't understand enough science to argue for one or the other. I'm just pointing out what I see :)

[brityank]

Bump and ping for reference.

I have a slow connect to the web, so these are the first real close-ups I've seen. What type of camera/film are these images made with? It seems they are not 'normal' but are IR enhanced [much like 'night-vision' rectifiers] and therefor the colors would be warped. Having seen someone hit and sliced open with a less than 1/2inch slab of ice from a building, I think your synopsis is right on the money. Thank you.

[Moonman62]

Ron Dettemore mentioned the color during his press conference yesterday. He noted that the color could be called light rather than white. I got the impression he was stalling and playing rope-a-dope. He knows the color is significant just like you've noted, and one day he's going to be held accountable.

[Cold Heat]

This is interesting, and I wonder if it was still aboard for this flight. Apparently the heating of the side wall of the shuttle is nothing new.

SHUTTLE INFRARED LEESIDE TEMPERATURE SENSING

The SILTS experiment will obtain high-resolution infrared imagery of the upper (leeward) surface of the orbiter fuselage and left wing during atmospheric entry. This information will increase understanding of leeside aeroheating phenomena and will be used to design a less conservative thermal protection system.

SILTS provides the opportunity to obtain data under flight conditions for comparison with data obtained in ground-based facilities. Six primary components make up the SILTS experiment system:

(1) an infrared camera,

(2) infrared-transparent windows,

(3) a temper ature-reference surface,

(4) a data and control electronics module,

(5) a pressurized nitrogen module and (6) window protection plugs. These components are installed in a pod that is mounted atop the vertical stabilizer and capped at the leading edge by a hemispherical dome. (The SILTS pod replaces the top 24 inches of the vertical stabilizer.)

Within this dome, the infrared camera system is mounted in such a way that it rotates to view the orbiter leeside surfaces through either of two windows-one offering a view of the orbiter fuselage and the other a view of the left wing. The camera is sensitive to heat sources from 200 to 1,000 F.

The camera's indium-antimonide detector is cooled to cryogenic temperatures by a Joule-Thompson cryostat. The camera's field of view is 40 by 40 degrees. Its rotating prism system scans four 100-line fields each second, with a 4-1 interlace, resulting in a 400-line image.

Each of the two infrared-transparent window assemblies consists of dual silicone windows constrained within a carbon-phenolic window mount. The windows and window mount assemblies are designed to withstand the entry thermal environment to which they would be subjected without active cooling. They are, however, transpiration cooled with gaseous nitrogen during experiment operation so that they do not reach temperatures at which they would become significant radiators in the infrared. A small thermostatically controlled surface between the two window assemblies provides an in-flight temperature reference source for the infrared camera.

The pressurized nitrogen system comprises two 3,000-psi gaseous nitrogen bottles and all associated valves and plumbing. The pressure system supplies gaseous nitrogen to the cryostat for camera detector cooling, to the external window cavities for window transpiration cooling, and to pin pullers that initiate the ejection of the advanced flexible reusable surface insulation window protection plugs upon SILTS activation to expose the viewing ports and camera.

The information obtained by the camera is recorded on the OEX tape recorder. The data, when reduced and analyzed, will produce a thermal map of the viewed areas.

The SILTS experiment is initiated by the onboard computers approximately five minutes before entry interface, which occurs at an altitude of approximately 400,000 feet. The camera operates for approximately 18 minutes through the forward-facing window and left-facing window, alternating evenly between the two about every five seconds.

After the six planned SILTS missions, an analysis of structural loads will determine whether the SILTS pod should be removed and replaced with the original structure or remain in position for other uses. The pod thermal protection system is high-temperature reusable surface insulation black tiles, whose density is 22 pounds per cubic foot.

[Jim Noble]

Ok, people, let's work the problem bump!

[Cold Heat]

MSNBC just ran some fantastic pics and videos of the insulation incident. Some were real close ups.

The hue of the dust was definately redish. I have no doubt.

NBC also verified the voracity of the reported tile loss over California. They said the guy was a astronomer with a telescope.

[small_l_libertarian]

On Fox News during Cavuto's repeat show last night, they had a very clear video of the insulation/ice falling off of the tank and hitting the wing. At the end of the video when the plume sprays out, you can very clearly see that the original "chunk" also comes out from under the wing.

The plume appears to be tile dust to me, too, but I'm basing it on the fact that I saw the chunk come out from under the wing, pretty much the same size/shape it went in, not the color of the plume (looking at the color was a very good idea, though).

(Now, I was viewing this video at midnight, so it may just be my eyes...)

[snopercod]

Thanks. Those are the best photos I've yet seen of the "debris". Here are my thoughts:

1. It looks like ice to me, too, not ET TPS. My guess is that it came from the ET LH2 repress line, the 2" line that runs up the left side of the tank which is used to repressurize the ET LH2 tank as the LH2 is sucked out of it during ascent. IIRC, the ET LH2 Repress Line is at ambient temps pre-launch, but pressurized with hot gasses from the engines on ascent. That could have melted off a chunk of ice.

2. Take a second look at the launch video and you will see frost actually growing on the intertank during ascent. Atmospheric conditions must have been right for ice built up on that line or it's attachments during pre-launch or ascent.

3. The impact area looks to me to be very close to where the LMG door was located. The white "vertical" line you see in the "enhanced" areas is the "bond line" between the wing and the fuselage. (It's not really a line, but just a change in curvature in the tiles which appears as a line in reflected light.)

4. The hinges of the 4'x12' +/- gear doors are along the bond line, and the door swings outboard upon closing. The front-outboard corner of the gear door is ligned up with the point of the leading edge where the chine sweeps outward. In picture #3, you can see that plume on the right side of the enhanced circle sweeping directly over the leading edge of the LMG door area. The front-outboard corner of the door is less than 3' away from the leading edge of the wing! (The main impact in the photos seems to be inboard of the bond line.)

5. The landing gear door area is one of the hottest areas of the shuttle on re-entry (second or third only to the nose cap and leading edges, I believe)

(I have the shuttle tile drawings in front of me as I type this. I haven't found my ET drawings yet. We boxed everything up when we left KSC...)

[lysol@whitehouse]

Observing Monday's news conference, Ron Dettemore's composure appeared to dramatically change when asked about the possibility of ice on the insulating foam, and how that would change estimates of damage to the tiles. His voice hardened and became loud as he appeared to obfuscate and hide behind "intelligent men assessed all possibilities and decided there was not a problem". None of the reporters challenged him at this point, following up with a marshmallow question of "what about the future of space flight?" Reminds me of the Challenger news conferences. Bless the heroes of Columbia.

[OldFriend]

Your analysis is the very best to date. Thanks for making it simple to understand and sounding so logical.

[Budge]

Good, Bones. That plume has had me intrigued from the first. Whatever the object is/was, insulation from the ET, ice, or a combination of the two, it was large before the impact.

As far as the plume, I wonder if the size would be consistant with only the object being shattered. Personally I don't think so, but that is only MHO.

[bert]

.....ET insulation is orange/brown in color......

..... The interior of the tile is a white.....

It seems to me these statements are contradictory. Based on long ago upclose observations of the material, I thought it was white throughout with a black exterior surface.

If a tile sheared off as opposed to becoming unstuck, the exposed sheer surface would be white. If on impact the fragment disintegrated into a powdery cloud, the appearance would be light colored, in, fact would be reflective, and would be visable as a plume.

Similar visable phenomena would result from an ice blob so I can reach no conclusion.

[sam_paine]

So if it was a plume of smashed tile, then there should be some evidence near the launch site, or perhaps residue on the SRBs? I assume it was fairly far downrange when this occured, thus over water? Oh well.

[ijcr]

Firstly the chemical composition of the foam insulation was changed recently due to the ban on the use of freon. The "new" foam doesn't maintain integrity quite as well under high heating conditions and some pieces have been coming off, so NASA sands the foam still thinner to design "minimums" to still protect the aluminum skin, yet decrease the amount of foam that potentially could come off.

Secondly, All the tanks come in from the factory a light tan in color, and can eventually reach a chocolate brown depending on how long it sits on the pad in the sun. Any orange tinting should be very subtle. Actually, the orange influence is attributed more to what the sunlight is contributing that day whether it be close to sunrise or sunset than anything else.

Thirdly,The super-lightweight ET's, which first flew in 1998, have an even lighter color.

Finally, public affairs now shoots a lot of their images with digital cameras and these cameras sometimes have trouble reproducing reds, yellows, and tans.Often in filming a rapid event will go to white,eg fill a balloon with a dark powder and film it being burst...the result is often a white cloud.

[RippleFire]

Something else of interest from http://brian.carnell.com/articles/2003/02/000003.html

More on Shuttle Foam Damage from STS-87

By Brian Carnell

Monday, February 3, 2003

This NASA page has notes by a NASA worker from 1997 about the "significant damage" done to STS-87 from the reformulated, Freon-free foam insulation flaking off during the Shuttle's ascent (emphasis added),

 

During the STS-87 mission, there was a change made on the external tank. Because of NASA's goal to use environmentally friendly products, a new method of "foaming" the external tank had been used for this mission and the STS-86 mission. It is suspected that large amounts of foam separated from the external tank and impacted the orbiter. This caused significant damage to the protective tiles of the orbiter. Foam cause damage to a ceramic tile?! That seems unlikly, however, when that foam is combined with a flight velocity between speeds of MACH two to MACH four, it becomes a projectile with incredible damage potential. The big question? At what phase of the flight did it happen and what changes need to be made to correct this for future missions? I will explain the entire process.

And intriguing comments about similar issues during STS-86,

 

The STS-86 mission revealed a similar damage pattern but to a much lesser degree than STS-87. The STS-86 tile damage was accepted ruled as an unexplained anomaly because it was a night launch and did not provide the opportunity for the photographic evidence the STS-87 mission did. A review of the records of the STS-86 records revealed that a change to the type of foam was used on the external tank. This event is significant because the pattern of damage on this flight was similar to STS-87 but to a much lesser degree. The reason for the change in the type of foam is due to the desire of NASA to use "environmentally friendly" materials in the space program. Freon was used in the production of the previous foam. This method was eliminated in favor of foam that did not require freon for its production. MSFC is investigating the consideration that some characteristics of the new foam may not be known for the ascent environment.

[Fitzcarraldo]

Excellent analysis! The way the solid object became a plume is significant. If that is shuttle tile pulverizing there was a real problem...

[spunkets]

Here's a page from NASA with 3 mpegs of the debris hit. It looks like ice rather than foam, because the foam is too resilient to explode like that, larger frags leaving the impact area would be evident. If the ice weighted 1 lb and was going 300mph, it would have 6K ft-lbs of energy. Since it was bigger than pint size, I'm sure it had more. The ship was said to be going ~1000mph(mach 1.3) at this point. I also e-mailed NASA to get the frame rate of those flicks. If they answer, I'll post it.