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.

[freepersup]

Check out # 1657- (not the debris field, but... better, the whole enchilada). I'll find it though.

[bonesmccoy]

http://www.moonglow.net/ccd/pictures/other/columbia_breakup.rm

Is this the video shot by the AZ kids?

[bonesmccoy]

I brought up the issue of the explosives in the MLG bay about 200 posts ago. However, we have yet to hear anything from the press conferences on the temp limits for the MLG explosives. I'm wondering if those temp limits were surpassed over California (creating those temporary brightenings of the orbiter's magnitude as visualized by astronomers).

[spunkets]

Can you manipulate the jpegs in your software?

[Cold Heat]

RE 1662

Downloading now, if not I will decripe verbally what I saw.

[Budge]

1584 - I do have a web page where we could put it, but I am not sure how to, a) make it runable from there, or b) available for download. Space there would be no problem.

By all means, send along the update. In the meantime, may I pass it along to any of the others who may want it?

[freepersup]

check out # 1657- NASA has put the sensor readings in sequence and arranged them along the shuttle flight path as it crossed over the southwestern U.S. of A.

Maybe you can find a corroborating or supportive indicator...

Yes- re: explosive bolts- I remember the thread (group) and yourself touching on the topic of the bolts (previously)

[bonesmccoy]

WOW! GREAT LINK!

I'll see if I can post some data from their maps

[NormsRevenge]

Thanks for the pdf link. Interesting. I'll need to check it out when my eyes are up to it and I can spend the time going thru the flightpath maps.

[Budge]

The disclosure focused renewed attention on possible catastrophic failures inside Columbia’s wheel compartment inside its left wing that may have attributed to the mysterious breakup.

Safety engineers believe an unusually large chunk of flyaway foam from Columbia’s external tank struck the shuttle on liftoff and may have damaged delicate insulating tiles near that area...

Looks like NASA is catching up with us at FR. :)

[John Jamieson]

Tell us more about those tests. I'll google them too.

[Budge]

I am probably late with this, but check the links in 1549 and 1557. Some very good timelines in a link in one of those.

[XBob]

Can you manipulate the jpegs in your software?

just barely. not sophisticated, it's only MS photo editor

[bonesmccoy]

Budge,

Can you jpg the graphic labelled "Crossing California"?

Let's see if we can predict the location of the object that separated from the orbiter and observed by the astronomers in Owens Valley.

Let's do an elementary physics problem. An object has a particular height and velocity. Calculate the distance that the object travels prior to impact.

Y = height
v = velocity

On the slide labelled "Crossing California" a blue dot over Yosemite National Park is labelled with the following data:
13:54:20 GMT +/- 60 sec (34)
(13:53:20/55:20)
Start of slow aileron trim change. GMT is approximate
Let us assume that the vehicle had increased drag just prior to this point due to a component that is creating drag.

Let is attempt to estimate the point at which the object creating the drag separated from the vehicle by comparing the astronomical observations with the inflight data acquired by Mission Control and then released by NASA.

The prior data point which NASA labelled is at:
13:54:10 GMT (33)
38.4162, -120.1739
LMG Brake Line Temp B - Start of Off-Nominal Trend - Temp Increase. H = 228460 ft. Mach 22.64
I will define this data point as CA-1

A second datapoint is labelled at:
13:54:24 GMT (35.5)
38.27043, -119.0681
Sys 3 LMG strut Actuator Temp - start of off-nominal trend - unusual temp rise
H=227437 ft
V=Mach 22.51

Using the two datapoints, I have created a line on my Microsoft MapPoint program (which appears to be the same program NASA is using).

I'm going to attempt to find the discussion written by the Cal Tech astronomers.

[freepersup]

I couldn't tell for sure- seemed like it's the one when I watched the shedding aspects unfold. The kids were talking between themselves in the one I saw. The only thing that seems different about this video and the kids is, they seemed to be filming more up into the sky (overhead) and this one seems to be more horizontal...

[Cold Heat]

This video, while interesting and does show a tile or something coming off, is not the video I saw,

The video I saw was clear and excellent quality. It had a time signature running in the bottom right. There was also audio.

The first frames looked similar to the above link but then he zoomed in.

The debris made quite a sight as it separated. It illuminated the contrail as it fell back. As it fell back the kid zoomed in on it, showing what I believe to be a long, possibly rectangular object, still glowing a bit but darkening as seconds passed. It seemed to be illuminated on the edges only. The kid watched and said....Look at that! Wow! Did you see that!

Then he panned back to the shuttle which was moving out of range and probably well over NM by now.

[Budge]

I'm not ignoring you, I'm afraid you're way ahead of me on this, Freepersup. I was too short on time this afternoon, and too tired tonight to do any analyzing. Off for a few days, that'll help get the cobwebs out.

[XBob]

Interesting idea, estimating the location.

At this point, I would estimate that the molecules are floating somewhere over the mid-atlantic.

I don't think any of the western 'flares' reached the ground. However, I may be wrong. That big one may be out there somewhere, but it seems to me that the flares over Owens Valley were only small ones.

[freepersup]

northwest of Kanab, Utah
13:55:49 GMT
"Orbital Sunrise" (Vehicle Moves From Earth's Shadow to Sunlight)

northwest of Marble Canyon, Arizona
13:56:02
QBAR = 40psf
Aft RCS Pitch Jets Deactivated
H 221,670'
mach 21.45

northwest of Marble Canyon
13:56:03
Left Lower Wing Skin Temp- Start of Off- Nominal Trend- Temp Reading Trending Down potential sensor/wire damage
H 221,612'
mach 21.44

This is the time line of the shuttle coming out of the southwest corner of Utah and into the northwest corner of Arizona. The kids filming at Waputki National Monument, northeast of Flagstaff will be picking the shuttle up at any moment on film, if they haven't already.

[bonesmccoy]

Formula for parabolic trajectory of a ballistic object: