|Jacked In Home -> A total amateur analyzes the Columbia data|
Updates and comments on this document can be found on my Slashdot journal in this entry.
Well, in the spirit of 'scratching my own itch', I put together an animation of those eight minutes from the NASA slides. Because eight minutes is quite a long time, I time-compressed at around 25 to 1, resulting in a twenty-second clip. Keep the actual time in mind when viewing it:
As you can see, the order of events is pretty clear. The animation begins at 13:52:00 GMT. Approximately 13:52:20 GMT some temperature sensors in the wheel-well start to show an anomalous rise in temperature. Quickly afterwards other sensors, far away in the back of the wing (but with their wiring harness placed between the wheel-well and the leading edge of the wing), suddenly fail. Then, after 13:54:13 GMT, more temperature sensors in the wheel-well show a rise in temperature followed nearly four minutes later by the wheel sensors failing. Twenty seconds later all telemetry is lost.
Other sensors located in the back of the wing, which had a wiring harness behind the wheel well, never did fail prior to loss of signal. Combine that factor with this image taken by high-resolution Air Force cameras:
It seems likely there was a loss of integrity in the leading edge heat shielding right in front of the wheel well. Note that these shields are not silicon tiles! Instead they are made of carbon and are thick blocks with a rounded edge that are bolted to the wing itself (which is flat on the front). These shield blocks are fastened so that they are allowed to expand with high temperature and they have 'T' pieces of carbon shielding that fit between them.
The failure mode itself might very well turn out to be quite minor at first, perhaps losing one of the in-between bits, or the bolts might not have allowed proper expansion. Perhaps some impact may have cracked and/or completely destroyed an entire shielding block. No matter, because the temperatures we are talking about are enough to cut through the aluminum structure of the wing like a hot knife through butter. This 'blow-torch' would not only have allowed hot air into the wing, but would have scattered molten metal droplets about as well. This scenario perfectly explains the sensor data to my, admittedly, uneducated eyes.
It will be interesting to see how close to the mark I am when NASA releases the official report. I will update this page at that time.
Jacked In Home -> A total amateur analyzes the Columbia data