Posted on 02/01/2003 4:25:45 PM PST by Sub-Driver
Columbia's Problems Began on Left Wing By THE ASSOCIATED PRESS
Filed at 6:56 p.m. ET
CAPE CANAVERAL, Fla. (AP) -- Investigators trying to figure out what destroyed space shuttle Columbia immediately focused on the left wing and the possibility that its thermal tiles were damaged far more seriously than NASA realized by a piece of debris during liftoff.
Just a little over a minute into Columbia's launch Jan. 16, a chunk of insulating foam peeled away from the external fuel tank and smacked into the ship's left wing.
On Saturday, that same wing started exhibiting sensor failures and other problems 23 minutes before Columbia was scheduled to touch down. With just 16 minutes remaining before landing, the shuttle disintegrated over Texas.
Just a day earlier, on Friday, NASA's lead flight director, Leroy Cain, had declared the launch-day incident to be absolutely no reason for concern. An extensive engineering analysis had concluded that any damage to Columbia's thermal tiles would be minor.
``As we look at that now in hindsight ... we can't discount that there might be a connection,'' shuttle manager Ron Dittemore said on Saturday, hours after the tragedy. ``But we have to caution you and ourselves that we can't rush to judgment on it because there are a lot of things in this business that look like the smoking gun but turn out not even to be close.''
The shuttle has more than 20,000 thermal tiles to protect it from the extreme heat of re-entry into the atmosphere. The black, white or gray tiles are made of a carbon composite or silica-glass fibers and are attached to the shuttle with silicone adhesive.
If a spaceship has loose, damaged or missing tiles, that can change the aerodynamics of the ship and warp or melt the underlying aluminum airframe, causing nearby tiles to peel off in a chain reaction.
If the tiles start stripping off in large numbers or in crucial spots, a spacecraft can overheat, break up and plunge to Earth in a shower of hot metal, much like Russia's Mir space station did in 2001.
Dittemore said that the disaster could have been caused instead by a structural failure of some sort. He did not elaborate.
As for other possibilities, however, NASA said that until the problems with the wing were noticed, everything else appeared to be performing fine.
NASA officials said, for example, that the shuttle was in the proper position when it re-entered the atmosphere on autopilot. Re-entry at too steep an angle can cause a spaceship to burn up.
Law enforcement authorities said was no indication of terrorism; at an altitude of 39 miles, the shuttle was out of range of any surface-to-air missile, one senior government official said.
If the liftoff damage was to blame, the shuttle and its crew of seven may well have been doomed from the very start of the mission.
Dittemore said there was nothing that the astronauts could have done in orbit to fix damaged thermal tiles and nothing that flight controllers could have done to safely bring home a severely scarred shuttle, given the extreme temperatures of re-entry.
The shuttle broke apart while being exposed to the peak temperature of 3,000 degrees on the leading edge of the wings, while traveling at 12,500 mph, or 18 times the speed of sound.
A California Institute of Technology astronomer Anthony Beasley, reported seeing a trail of fiery debris behind the shuttle over California, with one piece clearly backing away and giving off its own light before slowly fading and falling. Dittemore was unaware of the sighting and did not want to speculate on it.
If thermal tiles were being ripped off the wing, that would have created drag and the shuttle would have started tilting from the ideal angle of attack. That could have caused the ship to overheat and disintegrate.
Dittemore said that even if the astronauts had gone out on an emergency spacewalk, there was no way a spacewalker could have safely checked under the wings, which bear the brunt of heat re-entry and have reinforced protection.
Even if they did find damage, there was nothing the crew could have done to fix it, he said.
``There's nothing that we can do about tile damage once we get to orbit,'' Dittemore said. ``We can't minimize the heating to the point that it would somehow not require a tile. So once you get to orbit, you're there and you have your tile insulation and that's all you have for protection on the way home from the extreme thermal heating during re-entry.''
The shuttle was not equipped with its 50-foot robot arm because it was not needed during this laboratory research mission, and so the astronauts did not have the option of using the arm's cameras to get a look at the damage.
NASA did not request help in trying to observe the damaged area with ground telescopes or satellites, in part because it did not believe the pictures would be useful, Dittemore.
Long-distance pictures did not help flight controllers when they wanted to see the tail of space shuttle Discovery during John Glenn's flight in 1998; the door for the drag-chute compartment had fallen off seconds after liftoff.
It was the second time in just four months that a piece of fuel-tank foam came off during a shuttle liftoff. In October, Atlantis lost a piece of foam that ended up striking the aft skirt of one of its solid-fuel booster rockets. At the time, the damage was thought to be superficial.
Dittemore said this second occurrence ``is certainly a signal to our team that something has changed.''
It may have been possible to do an EVA... but to what purpose? Either the tiles are OK and you will have a safe re-entry or they aren't and you are going to die, either quickly attempting re-entry or slowly and painfully by asphyxiation. Why take the risk of an EVA to learn you must decide as a group how you are going to die?
I think it might be better to remain ignorant of the extent of the UNREPAIRABLE DAMAGE and not have to make that horrible choice. Perhaps, someone at NASA made it for them and elected that they not know at all of the potential for disaster. Since staying in orbit was NOT an option (no, gcochran, a resupply was not feasable in the time they had), the only possible option was to de-orbit and try to get the ship home. When all other options lead to certain disaster, you take the one that has only a slight chance of success... at least is a chance.
Had they elected to die in orbit to "save" the shuttle, I think they would have died painfully to no purpose. The altitude the shuttle was orbiting is actually NOT A STABLE ORBIT for such a large object... it is still in the atmosphere (very attenuated) and drag will eventually pull it down to burn in an uncontrolled re-entry in a very few months... probably before a salvage mission could be mounted with a new technology of tile repair that could be done in space... or a way of refueling and repowering frozen, dead shuttle and elevating its orbit.
These are just the grim realities. I am glad I didn't have to make the decision... if someone did.
We have to stop all space flights until it is perfectly safe.
Uh, how are we going to learn how to make it safe?
Guess what, OReilly. More people died today in automobile accidents than died in the space shuttle. All of these untimely deaths are tragic. Could we have done more to prevent those deaths? Probably. Could we have done more to prevent the astronauts deaths? Probably.
Am I going to stop driving my car? No. Would I go up in the next space shuttle? You bet your life, I would! And I would bet my life, I would.
If given a choice knowing they were going to die, do you think the astronauts would have preferred to die in one of those automobile accidents... or on the space shuttle?
I know what my choice would be. Somethings are worth risking your life.
That is my point...
And we could make cars that are perfectly safe and no one would die in them... but they would cost so much, travel so slowly, and be undesirable to drive.
All things in life are trade offs, economic and societal, life and death, choices we make for things we need and things we desire.
We are learning how to MAKE safer cars... and how to make Space Travel safer... but along the way we WILL make mistakes, we will have accidents... and some are unavoidable because of the trade offs that have to be made.
If we took your implied route, NO ONE would ever start. No progress would ever be made for fear that someone MIGHT GET HURT. That, my friend, is societal cowardice.
I have a question that MAY have been possibly answered today among the large number of posts, BUT I would first like to thank the engineers on here that know a helluva lot more about physics that I do. I've appreciated the crash-course in space travel. :
My question is based off of previous landings that are shown on tv. On the last several landings, and on the NASA website, there is a HUD view of the shuttle coming in. It's several minutes of display that is shown live on TV sometimes. I suppose that Houston has this recorded? I would think that would help decide the issue of whether the shuttle was coming in side-ways. (which looks that way to me) Any info will be appreciated. Matt
Could do it but also need kiln. What about the other thousand things that can go wrong?
Agreed. My point was that if a spare tile kit were carried along, blanks, a milling machine, cutters and bonding kit would have been part of such kit. Finally, an astronaut would have to receive tile replacement training.
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