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]

good, you got them - the radar was 1116 cst

the others, i sent also to spukets. perhaps you would like to replace the one of the others on your sit, with the horizontal one. I only needed 49 and 50.

[Budge]

1797 - 1813 - The same thoughts crossed my mind too. Then it dawned on me JimRob maintenance.

[Cold Heat]

I do not know about y'all, but I find this story laughable. Sensors are constantly being improved in the private sector. Better systems are available off the shelf now.

NASA is donating $4.5 million to a technology center in upstate New York this year, some of it aimed at developing better high-temperature sensors.

The Infotonics Technology Center, one of five Centers of Excellence in New York funded by both industry and government, specializes in designing high-resolution imaging and ultra-fast communications devices.

The destruction of the Columbia space shuttle on Feb. 1 has led to talks on developing better sensors at the technology center in this western New York town, said its chief executive, Duncan Moore.

''Now we know for sure the (shuttle's) underside got too hot,'' he said in Friday's Daily Messenger.

A hole in the shuttle's aluminum skin apparently allowed super-hot gases to penetrate the wing and destroy the spacecraft.

Sensors embedded throughout Columbia's left wing began recording unusual readings as the shuttle approached the California coast. Seven minutes after the first indication of a problem, Columbia broke up in the sky over Texas, killing its crew of seven.

[Budge]

1820 - Keep us posted, or post a report and ping. BTW, you haave Freep and e-mails. Good luck and stay safe.

[XBob]

sounds like the beginnings of a plan. Perhaps we could get a FReep for finding shuttle parts plan going. It's going to take me another month or so to get things ready. Still have to find a satellite computer hookup, and finish outfitting and filling the motor home.

seems like you got the best part of yours outfitted already (the FReeperette).

I'm not into ATV's or Motorcycles anymore though, but I know a guy who is.

Calling Blackie.

[Budge]

1821 - No need to replace them. Use what you wish.

[XBob]

yes, but that was 'unscheduled' maintenance, the site crashed. when the site came back up he scheduled maintenance for 1-3 am.

[XBob]

prices to get a change in the shuttle design start with

1. A truck to carry the paperwork and money
2. an arm and a leg
3. years and years of time
4. etc...

[DonnerT]

Don't remember who asked for this but here is the Shreveport radar on Texas Louisiana map.

Unfortunately Rand McNally doesn't put many town names on my maps.

[Budge]

1827 - I stand corrected. Last night was maintenance. I was panicky that night it went down.

[BraveMan]

Budge, that was a picture John Jamieson sent me and asked me to post. I believe it is; I've seen the picture before. JJ will have to comment on its authenticity . . .

[Budge]

Me. Thanks DT.

[DonnerT]

Haven't heard much about all the stuff that must be in Louisiana. Surely the most compact masses would travel farther?

[XBob]

there is shrieveport, right on I20. Here is mine, from 11:16 cst, which Budge kindly put up on his site:

[XBob]

1834 - the above is about 3 hours after destruction.

most debris was around Lufkin

[XBob]

remember, the Challenger. It took 2 1/2 years to get a change and flying again, which had been long before identified, and in fact, SRB design changes were COMPLETED, 18 months BEFORE the Challenger blew up.

[XBob]

many thanks - it is neat. I use a logitectrack ball marble with the ;ittle wheel. works good, but the software is not quite compatible. pressing down on the wheek (middle key) doesn't change size.

[spunkets]

This is from the image you cut. Comments?

[XBob]

good find

Well, it wasn't exactly a "find". It came from personal knowledge, since I have actually been in the tire lab at KSC.

---

sorry, i realized that was a questionable, as soon as i hit the post button. It is a question which should have been asked and anwered long ago by NASA.

i never got into the tire shop, but i did handle the new disk/caliper assemblies - about 300 lbs each - compact and very heavy.

[XBob]

excellent - many thanks.

and the original image is flying skewed and not exactly overhead, like the drawing, so it is distorted a bit.

Now are we viewing heat or bird in the actual image.

We need a better photo interpreter individual.

I think this is just about as good as we can do here.