Posted on 03/28/2009 2:59:50 PM PDT by bd476
Yes, I sure did. Knowledge of all possible contingencies doesn't predict their occurrence. Yet it still had to have been for even a Top-Gun Graduate/Navy Test Pilot such as Commander Gibson, one extremely white-knuckled re-entry.
If they had not successfully re-entered and landed at Edwards AFB, the entire crew would have been lost; the Shuttle would have been impossible to retrieve from the Pacific Ocean; no one would have known about the extensive damage to Atlantis' heat tiles; and Atlantis being the second Shuttle mission following the Shuttle Challenger disaster, without a doubt the entire Space Shuttle program would have ended.
While the debris investigation went on and the thermal protection material for the forward skirt, frustum, nose cap and aft skirt were changed on the next flight (March 13, 1989, STS - 29R), (new material that never again came off, that had been in work for over three years because of the inability of the old material, that caused damage to many of the heat tiles (on STS - 28R), to stay on, it was thought by the engineers at the time it came off due to impact with the ocean and not during flight), the people refused (although several individuals stated it was a problem and should be fixed), at that time, to believe that the thermal protection material of the fuel tank, due to its weightless nature, also caused damage and was a danger.
There's at least one politician in every group of people, including scientists. However, I wouldn't worry about the few politically motivated (read $$) scientists being able to influence all scientists everywhere.
It seems that the location of the tile failures is significant. In spite of the graphic description of damage and the hyperbole of the story, the engineers were correct and Atlantis landed as expected.
This is the closest thing I could find via a quick search:
Am I reading your and the original posts correctly that the insulating foam that came loose on this mission to damage the tiles is not the same stuff as what was changed, “to protect the ozone layer” to the material that eventually brought down Columbia? If this were the THAT foam, before the greenie change, than it would tend to disprove the theory of some that that foam change, and thus environmentalist concerns, was at least partially to blame for the Columbia disaster.
Zirconium, nor its impure oxide Zirconia are not used in the manufacture of the Shuttle tiles, according to NASA.
Instead the High-Temperature Reusuable Surface Insulation Tiles (HRSI) are made of nearly pure silica.
"The HRSI tiles are made of a low-density, high-purity silica 99.8-percent amorphous fiber (fibers derived from common sand, 1 to 2 mils thick) insulation that is made rigid by ceramic bonding. Because 90 percent of the tile is void and the remaining 10 percent is material, the tile weighs approximately 9 pounds per cubic foot. A slurry containing fibers mixed with water is frame-cast to form soft, porous blocks to which a collodial silica binder solution is added. When it is sintered, a rigid block is produced that is cut into quarters and then machined to the precise dimensions required for individual tiles.
HRSI tiles vary in thickness from 1 inch to 5 inches. The variable thickness is determined by the heat load encountered during entry. Generally, the HRSI tiles are thicker at the forward areas of the orbiter and thinner toward the aft end. Except for closeout areas, the HRSI tiles are nominally 6- by 6-inch squares. The HRSI tiles vary in sizes and shapes in the closeout areas on the orbiter. The HRSI tiles withstand on-orbit cold soak conditions, repeated heating and cooling thermal shock and extreme acoustic environments (165 decibels) at launch..."
NASA: High-Temperature Reusable Surface Insulation Tiles
The space shuttle engine contains a copper-silver-zirconium alloy:
"The space shuttle engine, for example, uses a copper-silver-zirconium alloy..."
Structural Materials in Aerospace Systems
That's acoolerrh, lol, interesting demonstration. Thanks for posting the photo, TXnMA!
If you had read the entire story, you would have noted that NASA engineers were in fact surprised by the extent of damage to the heat tiles.
If you can't bother to read an entire story, go argue with someone else, or better, and with all due respect to Commander Aldrin, just Buzz off.
I believe they are ceramic in some form or other. Mr G’s father was a scientist (ceramic engineer) and helped develop them.
That’s frightening. That article should be required reading in college, especially in the sciences. Thanks.
Thanks, XBob. That would have been frightening to see. Which one was it?
Society would collapse if we banned RTV and duct tape.
Even if it was a highly secret military mission, there were channels for providing this crucial mission safety info. back to shuttle engineering and mission operations, so they could take corrective action for future missions. It wouldn't necessarily have prevented a future catastrophic incident, but shutting up about a clear mission safety issue should never be acceptable.
But sadly I am all too aware of the tyranny at NASA that would keep this crew from passing on this safety info. even to fellow astronauts. And guess what, George Abby, that tyrant of NASA JSC at that time is now advising Obama on space policy. So look for more fear and loathing at NASA.
Robert "Hoot" GibsonHe was always more popular than his flatulent colleague, Paul "Toot" Mifinger.
“Thanks, XBob. That would have been frightening to see. Which one was it?”
I think subsequently they made a modification where they put some special metal plates over the shaft and under these tiles, for critical area protection.
25 - “have seen a dramatic photo of a 3” cube of tile material that was heated red hot in the center, and it was being held by opposite corners betwen a man’s thumb and middle finger — and the interior was still visibly glowing red hot.”
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