NASA investigators have concluded that a piece of insulating foam that peeled off from the external fuel tank and hit the left wing of the space shuttle Columbia during its launch is the root cause of the subsequent catastrophe, reports USA Today.
Columbia lifting off from launch pad Jan 16.
WorldNetDaily has reported the briefcase-sized chunk of insulation foam weighed 2.67 pounds and struck the ship at 500 miles per hour.
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NASA engineers believe it caused a hole to open up in the front edge of the orbiter's left wing, which allowed 3,000-degree gases to burn into the wing during re-entry. This breach caused the shuttle to disintegrate over Texas on Feb. 1, killing all seven astronauts on board.
A pair of internal NASA studies obtained by the Orlando Sentinel fit the pieces of the puzzle together to draw this conclusion. According to the Sentinel, an analysis of sensor readings, re-entry images and debris damage – understood from the collection of some 70,000 pieces of debris representing 37 percent of the shuttle – traced the location of the hole in Columbia's shell of heat-protecting tiles to the same place where the foam struck some 80 seconds after liftoff on Jan. 16.
Circumstantial evidence points to two tiles, or RCC panels numbered 8 and 9, as the trouble spot.
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WorldNetDaily also reported in early February that a former deputy director of the space shuttle program, Sam Beddingfield, maintained a single failed tile "in the wrong place" would cause the spacecraft's aluminum frame to "just collapse."
NASA's conclusion marks a turnaround for the space agency, which strenuously argued against the foam-impact theory in the early days of the investigation. Mission Control assured reporters that engineers had concluded that any damage to the wing was considered minor and posed no safety hazard.
"When we analyzed it for 10 days we did not think that it was an issue," said NASA's shuttle program manager Ron Dittemore, referencing the engineering report issued on the 12th day of the mission which indicated the "potential for a large damage area to the tile" but, upon analysis, engineers concluded there was "no burn-through and no safety-of-flight issue."
"The best and brightest engineers we have who helped design and build this system looked carefully at all the analysis and the information we had at this time, and made a determination this was not a safety-of-flight issue," said Dittemore.
Still, the agency went back to the drawing board and redid the analysis done during the mission to see if any "erroneous assumptions" or "mistakes" were made.
Coincidentally or not, Dittemore announced today he is stepping aside as manager but would stay on to ease the transition for his successor.
While the foam remained a "primary area of emphasis" for NASA investigators over the past 11 weeks, other theories were entertained.
In recent weeks, attention refocused on the foam-impact theory after investigators concluded the computer model that convinced engineers that Columbia could safely return to earth lacked the right data to be fully accurate.
The group of Boeing engineers who carried out the initial analysis needed more data about where the foam had hit and asked NASA to take pictures of the orbiting shuttle to assess the potential damage. But no pictures were taken due to a "miscommunication" between the engineers and NASA.
Meanwhile, investigators delving deeper into the cause of the liftoff-foam incident found 74 deformities in the foam insulation on an external fuel tank identical to that used during Columbia's launch, said members of the independent Columbia Accident Investigation Board, or CAIB, in its weekly briefing yesterday. One such deformity, an air pocket, measured 2.4 inches. The deformities are said to explain why the chunk flew off.
As WorldNetDaily exclusively reported a day after the Columbia disaster, NASA has known about the shedding of external tank insulation on launch for six years. In 1997, during the 87th space shuttle mission, similar tile damage was done during launch when the external tank foam crashed into them during the stress of takeoff.
The problems began when the space agency switched to materials and parts that were considered more "environmentally friendly," according to a NASA report obtained by WorldNetDaily.
"During the STS-87 mission, there was a change made on the external tank," said the report. "Because of NASA's goal to use environmentally friendly products, a new method of 'foaming' the external tank had been used for this mission and the STS-86 mission. It is suspected that large amounts of foam separated from the external tank and impacted the orbiter. This caused significant damage to the protective tiles of the orbiter."
Members of the Columbia Accident Investigation Board examine pieces of Columbia debris.
NASA's conclusion that a known problem brought down Columbia is sure to raise new concerns about the space agency's safety procedures.
A final determination of the cause of the shuttle disaster, however, rests with CAIB. Its final report and recommendations are due this summer.
"We're beginning a new phase" in which "the board deliberates more and reviews what it is that we know, what it is that we don't know and ... what kind of work we're going to have to pursue in order to change more of the 'I don't knows' into 'I do knows,'" the Washington Post quotes board chairman Harold Gehman as saying.
NASA officials are scheduled to present their analysis to CAIB members tomorrow.
Gehman said the board is "about 80 percent in agreement" with NASA's theory, according to USA Today.
Meanwhile, NASA announced today that the space shuttle fleet, which has been grounded since the Columbia disaster, could return to flight within a year.
That's good news to the astronauts aboard the international space station, who face supply shortages of water, food and spare parts.