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.''
The ISS flies at about 52 degrees inclination at an altitude of about 205 nautical miles. The Columbia was flying at 39 degrees inclination, at an altitude of 1f0 nm. The distance and relative speed (roughly 20,000 mph) precludes a manageable "eyeballing."
There are means of trying to do this, however, and NASA should have at least attempted it -- easy to say in hindsight.
Americans don't know the meaning of the word, can't!!
If Johnson & Johnson can invent an adhesive to stick on my greasy nose (nose strip), then our best scientists can invent a Lambeau Field-like array of subsurface heating wires to maintain temperatures sufficient for tile repair on critical shuttle wing edges.
Yeah, I heard the guy at the press conference talk about some of the previous incidents. I wasn't impressed, imo, it wasn't an excuse for not doing a visual check.
I used to launch planes off of aircraft carriers. Not that that equates to a shuttle launch.
The concept of being responsible for the lives of others is the same though.
It was my responsibility to ensure that the catapult that was going to launch the pilot and/or aircrew that our machinery was working. If we screwed up, there was a chance someone was going to die or you lose or damage costly equipment.
I'd never in good conscience not check for damage if something abnormal had occurred, even if previous events had turned up negative or were deemed non-critical.
Imo, it sounds as if they, (mission control) fell into the "cry wolf" syndrone. After X previous impacts why check anything?
I heard the guy say that they had ran different analyses which sounds great but doesn't compare to doing a look see.
Perhaps the wing was fine as projected by the analyses and the shuttle failed due to some other factor, but, since mission control failed to look, perhaps we'll never know.
So you think that the magicians in Florida and Houston with the help of seven astronauts could have "found" a way to get Columbia to the ISS by "lightening the load" enough so the available Delta V would be sufficient. That kind of magic only takes place in Hollywood or Disneyland.
The Apollo 13 team worked with what was at least theoretically possible. Getting Columbia from its planned orbit and docking it with ISS was not even theoretically possible. It is not "bull..." it's reality.
Rope? What rope? I would be very surprised if a rope was included on the mission manifest.
MMU? What MMU? This mission did not include any EVA plans. NASA would have not launched an MMU on Columbia if an EVA was not on the agenda... Too expensive and too wasteful of payload space and delta V needed for other necessary items.
This thread seems to be moderated by pro-NASA types... I heard the same press conference but the reason given for no concern was that they had no capability for in-orbit tile repair. I have said several times, that GIVEN that FACT I'll bet even some FRers could have come up with some suggestions. I know that sounds like heresy to Auranautical Engineers... but deal with it!
Not practical. The propellant requirements for such a craft would be prohibitive (many tens of thousands of pounds of prop), due to the requirement for this rescue vehicle to perform huge orbit plane changes. This mission was flying at 39 degrees inclination. An 30 degree plane change requires about 4100 m/sec of propellant -- which, for a re-entry- and rendezvous-capable satellite (about 50,000 kg) translates into about 40,000 kg of propellant, just for plane changes. All told, you'd be talking about a Shuttle-sized vehicle, or larger.
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