WASHINGTON, Feb. 22 (UPI) -- As many as three pieces of debris were ripped off and propelled at hundreds of miles per hour toward the shuttle Columbia, possibly hitting the left wing, according to a document made public Friday by NASA.
The Jan. 24 document was a report by a team of Boeing engineers who used computer modeling to declare the shuttle was likely not seriously damaged.
Two previously released Boeing reports focused on just one chunk of material that may have been foam, or a combination of foam, ice and underlaying insulation.
"At about 82 seconds into the flight, multiple pieces of debris were seen emanating from the ET tripod area and later seen impacting the Orbitor lower surface," the report by Boeing engineer Carlos Ortiz said.
All three pieces were 20 inches long, with one 16 inches wide and the other two 10 inches wide. Their thickness varied from 6 inches to 2 inches.
"Debris appeared to brak up upon Orbiter impact," the Boeing report said.
At the same time NASA published more e-mails of engineers at the Langley Research Center in Virginia, one warning that were one of the chunks of debris composed of ice instead of foam it would have hit the wing with the force of a 500 pound safe traveling 365 miles per hour.
But the Boeing analysis and the e-mails had not directly raise a warning that what debris had been observed had necessarily caused fatal damage.
The Boeing analysis was presented to the Columbia Mission Management Team Jan. 27, according to NASA, "with the conclusion that the effects of the debris did not pose a safety of flight concern for Columbia." Mission managers, NASA said, "concurred with that conclusion."
The printed analysis was only part of the Boeing presentation, and including "extensive verbal communication," NASA said.
Aviation Week magazine earlier reported that NASA documents as far back as 1988 showed that Columbia's left wing was exceptionally rough, presenting a possibility of more damage were there any impact of debris.
A gouge in the heat resistant tiles could, a 1988 flight readiness review said, generate temperatures above 3,000 degrees, exceeding the heat resistance of even the special tiling material.
The existing roughness, with tiny ripples only 0.2 of an inch high, would be greatly exacerbated were a gouge to produce more turbulence at the extremely high speed of re-entry, the early report said according to the magazine.
The left wing of the shuttle produced unusual temperature readings during re-entry just before the shuttle was ripped apart.