[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...)

[exnavy]

On Sat. afternoon I heard a nasa spokesman say "there was a midcourse autopilot correction due to extreme high level buffeting and turbulance". Do you suppose that turbulance could have caused the loss of more loosened tiles than would have normally occured?

[snopercod]

I just saw the same stop-frame video on Fox. What looks like a plume in pic #3 wasn't moving, so disregard what I said about it in my paragraph #4.

[bonesmccoy]

Great comments (when you're not bagging on OMDP in California)!

1. ET LH2
I think you may have missed my point. The plume color suggests that TPS silica was aerosolized by the impact. I don't believe that ET insulation would make a plume like the one observed on the launch replay film.

3. Landing gear door
Heating loads at the landing gear door are high. It has been known for many years that loss of TPS near the gear door would create potential for loss of vehicle. However, penetrations around the orbiter are plentiful. There are any number of different penetrations that have higher heating loads than others. I share your observation regarding the Main landing gear door's conspicuous location near the ice impact.

[exnavy]

Just heard on FOX news that tiles/wing parts found in Kalifornia.

[finnman69]

CLOSE UP OF EXTERNAL TANK

HI RES CLOSE UP

COMPLETE STS-107 OFFICIAL PICS

[Gracey]

If it is ice, as you suggest, would the ice be forming on top of the ET SOFI? I thought the purpose of the TPS was to keep the cryogenic liquids from dissipating their low temps and to prevent formation of ice (from falling?)

Are there any places on the ET where there is no SOFI? I've seen it in the VAB but can't remember any areas not covered. Been too long, and I'm getting old.