Investigators: Shuttle's Exterior Pierced During Fiery Descent

Associated Press ^ | Feb 13, 2003 | Ted Bridis Associated Press Writer

[OutSpot]

WASHINGTON (AP) - The space shuttle's skin almost was certainly pierced, allowing superheated air inside the left wing and possibly the wheel compartment during Columbia's fiery descent through Earth's atmosphere, investigators said Thursday.

In its first significant determination, the accident investigation board announced that heat damage from a missing tile would not be sufficient to cause unusual temperature increases inside Columbia minutes before it disintegrated. Sensors detected an unusual heat buildup of about 30 degrees inside the wheel well before the accident.

The board determined those increases were caused by the presence inside Columbia of plasma, or superheated air, with a temperature of roughly 2,000 degrees. It said investigators were studying where a breach might have occurred to allow plasma to seep inside the wheel compartment or elsewhere in Columbia's left wing.

The announcement focused renewed attention on possible catastrophic failures inside the wheel compartment that may have attributed to the Feb. 1 breakup that killed seven astronauts.

Officials are not sure where a hole might have opened in Columbia's skin, NASA spokesman James Hartsfield said. But he said the leading edge or elsewhere on the left wing, the fuselage or the left landing gear door were prime candidates.

"Any of those could be potential causes for the temperature change we saw," Hartsfield said. "They do not and have not pinpointed any general location as to where that plasma flow would have to originate."

The board dismissed suggestions Columbia's left landing gear was improperly lowered as it raced through Earth's atmosphere at more than 12,000 miles per hour. NASA disclosed earlier Thursday that a sensor indicated the gear was down just 26 seconds before Columbia's destruction.

If Columbia's gear was lowered at that speed - and in those searing temperatures as the shuttle descended over Texas from about 40 miles up - the heat and rushing air would have sheared off Columbia's tires and led quickly to the spacecraft's tumbling destruction, experts said.

Officials said they were confident that unusual sensor reading was wrong. Tires are supposed to remain raised until the shuttle is about 200 feet over the runway and flying 345 miles per hour.

Two other sensors in the same wheel compartment indicated the gear was still properly raised, they said.

While Columbia's piloting computers began almost simultaneously firing thrusters struggling to keep wings level, officials said a mysterious disruption in the air flowing near the left wing was not serious enough to suggest the shuttle's gear might be down.

The investigating board concluded that its research "does not support the scenario of an early deployment of the left gear."

NASA also confirmed that searchers near Hemphill, Texas, about 140 miles northeast of Houston, recovered what is believed to be one of Columbia's radial tires. A spokesman was not immediately sure which of the shuttle's six tires was found.

The tire was blackened and sustained a massive split across its tread, but it was impossible to know whether the tire was damaged aboard Columbia or when it struck the ground.

The board's announcement came one day after NASA released e-mails showing midlevel safety engineers in Virginia and Houston considered the risks of tires bursting inside Columbia's belly from heat damage.

Robert H. Daugherty, responding to an inquiry from Johnson Space Center, cautioned in one of those e-mails that damage to insulating tiles near the landing gear door could cause one or more tires inside to rupture, perhaps ending with "catastrophic" failures that would place the seven astronauts "in a world of hurt."

Ret. Admiral Harold Gehman, who heads the panel investigating the Columbia accident, called Daugherty's concerns "one of the many, many interesting leads that we have."

AP-ES-02-13-03 1819EST

[NormsRevenge]

LOL.. We are all novices in the eyes of God.. and justifiably so . :-)

[Bronco_Buster_FweetHyagh]

"The space shuttle's skin almost was certainly pierced, allowing superheated air inside the left wing and possibly the wheel compartment during Columbia's fiery descent through Earth's atmosphere"


Um. Maybe I'm missing the significance. OF COURSE it was pierced. Hello? Did they see the videotapes? The thing blew up. That wouldn't have happened without a breach in the hull. It did not explode from within.

Sorry, but I already know the sky is blue.

How about them telling us why, after they KNEW the underwing on the left side took such a huge hit during take-off, why they did not do more to inspect the damage before sending those poor men and women to their death.

[TomT in NJ]

I believe the tires aren't inflated until just before the shuttle lands - probably to prevent any potential tire explosion from destroying the shuttle. Having said that, if the wheel cover fell off or the seal was breached by superhot plasma, then the shuttle wouldn't last too long.

[harpo11]

"UNLEASH THE ENGINEERS!"

Absolutely!

[NormsRevenge]

Reuters version of same info from Yahoo! News ..

By Deborah Zabarenko

WASHINGTON (Reuters) - The extreme heat observed on the shuttle Columbia's left side during its fatal re-entry could have been caused by hot plasma penetrating the craft's wheel well, independent investigators said on Thursday.

Reuters Photo

Plasma is the super-heated gas that surrounded the shuttle as it streaked toward a landing at Kennedy Space Center (news - web sites) on Feb. 1. Plasma typically envelops a fast-descending space shuttle, but this time, preliminary analysis indicates it may have gotten inside the spacecraft's protective surface.

"Preliminary analysis by a NASA (news - web sites) working group this week indicates that the temperature indications seen in Columbia's left wheel well during entry would require the presence of plasma," the Columbia Accident Investigation Board said in a statement forwarded by NASA.

However, the board said the heat was so excessive that it could not have been caused by the absence of just one missing tile in the last minutes of flight.

This is significant since questions have centered on the possibility that some of Columbia's heat-shielding tiles were knocked off by a piece of foam insulation that fell off the shuttle's external fuel tank about 80 seconds after launch, apparently striking the left wing.

The board said investigators were looking at other ways the shuttle's skin might have been breached to let plasma into the wheel well area or elsewhere in the wing.

They also discounted fears that a problem with the landing gear on the left side of the spacecraft might have caused the shuttle to disintegrate over Texas, as a NASA engineer suggested in an e-mail two days before the shuttle's demise.

PROBLEMS ON COLUMBIA'S LEFT SIDE

"Other flight data including gear position indicators and drag information does not support the scenario of an early deployment of the left gear," the board said.

The board's statement was distributed by NASA, which has already come under criticism for failing to keep its distance from the independent inquiry that was appointed just hours after Columbia broke apart.

After a bruising four-hour congressional hearing on Wednesday with just one witness -- NASA Administrator Sean O'Keefe -- the space agency amended the investigative board's charter to address concerns about its independence.

The search for debris from Columbia continued in Texas, where a preliminary analysis of low-frequency sound wave recordings indicated the shuttle exploded between the cities of Amarilla and Lubbock, about 330 miles west of Dallas.

The data from sensitive devices that record infrasound, or low-frequency sound waves inaudible by humans, was sent to NASA, said Eugene Herrin, a geophysicist at Southern Methodist University in Dallas.

Herrin said data indicates a single explosion over Texas. A monitoring station in New Mexico showed the spacecraft as being intact as it passed over that state, he said.

Scientists operate a worldwide system of infrasound detectors that record items such as sonic booms. The devices look for any disturbance in the atmosphere such as a nuclear blast, meteor flights or even hurricanes.

Herrin said the infrasound likely recorded the moment when the shuttle blew apart, but the findings were preliminary.

The search on the ground shifted to Anderson County, west of Nacogdoches, where most of the reported shuttle debris fell. Officials said they have likely found more parts from the shuttle's wings and are checking serial numbers on recovered parts to see if they came from the left wing.

[YOMO]

If it launched today they could use all the Duct Tape everyone is buying.

[X-FID]

I would guess any damage near the leading edge of the wing would be a major problem, even if it was 1 tile, it could cause a chain reaction IMHO. There are many others more knowledgable about the shuttle than me around here though.

[Cvengr]

A tragic event and worthy our condolensces. This report needs to be well published. It's the first one I've read from NASA which reaffirms faith in their professionalism. Thanks for posting it.

[dtel]

I see what you are trying to say about the wheel well, but the sensors began failing before the wheel well.
It was one of the last sensors to go.
The heating started at the junction of the wing and fuselage,(check the press conferences for you anal geeks), this could indicate several problems including coming in off tangent.
Nobody knows yet what happened and it is way too early, to hang our hat on a cause.
It is easier, to eliminate certain causes at this point, than to pinpoint the cause.
I agree the foam is a problem, but it is a known problem that occurs every flight. This is nothing new.
Blowing up on re-entry is.

[LasVegasMac]

It was re-engineered to haul seven different people of diffenrent ethnic persuasions into space.

It was re-engineered, so as to be so simple to fly that they could even launch school teachers, professors, et al., into space.

PC' ism at its finest.

Talk about hot gas.

VLM

[_Jim]

The Shuttle was designed in the late 60's, early 70's, it is a Flying Camel.

And it's been CONSTANTLY improved and re-designed since then.

UNTIL you have a chance to repeal certain laws of physics - the basic PROBLEMS of space flight remain and your APPROACH to solving certain problems will remain along THE SAME LINES as the space shuttle ...

[RightWhale]

The tire was blackened and sustained a massive split across its tread, but it was impossible to know whether the tire was damaged aboard Columbia or when it struck the ground.

Are we allowed to guess?

[RightWhale]

If the wing was corrupted by the foam, it would have come apart during the sixteen days they were in space.

Sure about that?

[_Jim]

It was re-engineered, so as to be so simple to fly that they could even launch school teachers, professors, et al., into space.

PC' ism at its finest.

Huh?

Are you overlooking the two flight officers who sit up front?

VARIOUS portions of 'flight', BTW, are ONLY controllable by computer due to the subtlty of CONTROL RESPONSE required to maintain the shuttle's ATTITUDE (LIKE during re-entry) ...

[_Jim]

If foam had corrupted the skin of the craft early in flight, sensors would have failed well before re-entry.

The flight *into* space isn't *quite* the ride that they take back *into* the atmosphere (commonly called re-entry) -

- you do know this don't you?

[dtel]

Sure about that?

Think about it.
When do the forces of aerodynamics quit working during space flight?
The foam came off very early in flight, they were not in outer space, the rocket was obviously still attached.
They were gaining speed and thus enduring tremendous force.
If the wing were fatally compromised during this acceleration phase, it almost certainly would have exhibited some major sensor failure before the re-entry phase.

[Doe Eyes]

The shuttle is launched with the tires uninflated, if I am not mistaken. At what point in the re-entry process are they re-inflated, relative to the shuttle's re-entry timeline?

I previously seached the net for the answer to this very question. Never found the answer. The tires are inflated to about 300 psi and rated to 900 psi. They are only used for one or two landings.

[MississippiMan]

I would like to see a better space vehicle built.

Agreed. For starters, I wonder if there's not a more durable thermal protection system that can be put in place now instead of 28,000 glued-on tiles.

MM

[dtel]

I do understand that.
I also understand that it takes tremendous force to get into orbit.
Something happened at the junction of the wing and fuselage according to the sensors.
It spread through the wing, knocking out sensors as it progressed.
If the puncture had occurred during launch, don't you think the sensors would have picked it up?
Maybe the evidence will show a heat rise in that area early in flight, we shall wait and see.