Fox News today reported information given out by Shuttle program manager Ron Dittemore I find quite useful:
“He [Dittemore] added that engineering data shows a rise of 20 to 30 degrees in the left wheel well about seven minutes before the spacecraft’s last radio transmission. There followed a rise of about 60 degrees over five minutes in the left hand side of the fuselage above the wing, he said.
The shuttle temperature rose the normal 15 degrees on the right side over the same period, he said. All the readings came from sensors underneath the thermal tiles, on the aluminum hull of the craft.
The temperature spikes were accompanied by an increased drag, or wind resistance, that forced Columbia’s automated flight control system to make rapid adjustments maintain stability. Dittemore said the corrections were the largest ever for a shuttle re-entry, but still within the craft’s capability.”
If you put this together with other information, the picture starts falling together. An amateur astronomer in California saw an orange trail before the shuttle crossed the US Pacific coast. This roughly matches up in time with the sensor data and I believe what this man saw was the ionization trail of material being burned off the port wing. I am unable to state what material it was, but perhaps someone who did more than barely pass Qualitative can suggest. I can only think of Potassium (K) and Sodium (Na) of course those would be likely constituents of the tiles (I think – I have not dug into literature to refresh my memory on the tile ceramic). I out right do not remember the colour of ionized Aluminum; there are many other possibilities as well, such as hydrazine or hydraulic leaks.
But his description of “an L shape” makes me think of a tile or tiles unbonding and disintegrating into powder as they smash against the pitched up wing, and then being ionized into a burst of glowing plasma… followed by a steady erosion of surrounding tiles in the 3000F+ slipstream. A spectrogram would have been wonderful for the investigation team.
His photos may well show the beginning of the end, the initiation of an unzipping of tiles.
NOTE: The DOD sometimes uses the re-entering shuttle as a sensor test target for space defense systems. It is possible NASA is already getting such information. I have seen unclassified photos of a shuttle re-entry taken by experimental DOD optical systems. Such might exist this time as well.
I have absolutely no way of knowing. This is pure (but “educated”) speculation on my part.
STILL MORE: Doug Jones from XCOR may also have seen tiles disintegrating if I am right. He posted a comment here on Saturday:
“I watched the reentry from Mojave, CA at about 0553 this morning. Although there was some light haze (clearly visible when viewing Venus and Jupiter with 10×50 binoculars while waiting for the event), I was able to see an orange dot leaving a glowing trail behind it. At about the time of closest approach (about 220 miles, I believe) the brightness flared for an instant and a small speck came away from the main body, drifting backwards relative to it. Over about ten seconds, it dimmed and went out, then perhaps thirty seconds later the shuttle flared again but no debris was visible.”
Dale,
Do you think the ice or foam breaking off during launch and hitting the wing had anything to do with what happened?
Yes, you should go back and read the early posts where I discussed this in more detail. But additional information. The problems with the insulation seem to have started with a “green” initiative to use a more “environmentally friendly” insulating material.
My guess is the stuff is allowing water vapor to freeze inside itself and the expanding ice causes delamination… and when the ice melts the slip stream rips the stuff off.
There were somewhat similar delamination problems that killed the Lockmart spaceplane project. The composite tank delaminated during a static ground test for the sort of reason I mentioned above, although there was no greenery at fault there, just materials design problems caused by pushing too many technologies too far at one go.
Everyone interested in the Columbia failure should go here:
Feynman on Challenger
The money quote is:
“There are several references to flights that had gone before. The acceptance and success of these flights is taken as evidence of safety. But erosion and blow-by are not what the design expected. They are warnings that something is wrong. The equipment is not operating as expected, and therefore there is a danger that it can operate with even wider deviations in this unexpected and not thoroughly understood way. The fact that this danger did not lead to a catastrophe before is no guarantee that it will not the next time, unless it is completely understood. When playing Russian roulette the fact that the first shot got off safely is little comfort for the next. . . . . . . “