Engineer's Emails Warned Of Potential Crisis

In the days before Columbia disintegrated upon re-entering Earth's atmosphere, a NASA safety engineer emailed his supervisors, warning the shuttle was at risk for a breach near its left wheel. The email suggested others in the space agency weren't treating the possibility seriously enough.

"We can't imagine why getting information is being treated like the plague," the engineer wrote in one of a series of e-mails released by NASA on Friday.

By now, most of us have seen the video of Columbia's lift-off. Just 80 seconds into the flight of STS-107, a chunk of insulating foam can be clearly seen to break away from the huge orange fuel tank and impact the orbiter on the underside of the left wing. Now, newly-released documents show Columbia may have been struck by as many as three large chunks of foam that smashed against delicate insulating tiles.

Engineer Robert Daugherty, who works at NASA's Langley research facility in Hampton, Va., explicitly warned in an email Jan. 29 that "one of the bigger concerns" was that damage to thermal tiles near Columbia's wheel compartment seal could permit a breach there. He appeared mostly worried about pilots struggling to land Columbia with one or more tires damaged from extreme heat.

"It seems to me that if mission operations were to see both tire pressure indicators go to zero during entry, they would sure as hell want to know whether they should land with gear up, try to deploy the gear or go bailout," Daugherty wrote.

The accident board investigating the disaster has previously determined that Columbia almost certainly suffered a devastating breach along its wing and possibly its wheel well - one that allowed searing air to seep inside during its descent at nearly 12,500 miles per hour. At this point, investigators believe the heat literally melted parts of the wing, causing Columbia to disintegrate over Texas.

Earlier this week, investigative board member James Hallock said investigators were "very much interested also in the landing gear door itself, because once again you have tiles all around the area, but you also have seals."

Unusual temperature readings inside the wing and wheel compartment began within minutes of the shuttle's re-entry, far off the coast of California.

Senior Controllers Never Knew About The Debate

Senior NASA officials maintain concerns expressed in emails among midlevel engineers such as Daugherty were part of a "what-if" analysis, and that even these engineers were satisfied with Boeing's conclusions.

"During the flight, no one involved in the analysis or the management team or the flight team raised any concerns," said NASA spokesman James Hartsfield on Friday.

But the emails disclosed in Washington questioned some details about assurances by shuttle contractor Boeing that the foam impact was of little or no consequence. Some of the emails included underlying assumptions about the likelihood of minor damage from a large chunk of breakaway foam and whether damage to Columbia might have been caused by falling ice.

The emails also include references by Daugherty and another Langley employee, Mark J. Shuart, about secrecy within NASA about the study of risks to Columbia. Shuart wrote Jan. 28 to two other employees, referring to the foam strike, "I am advised that the fact that this incident occurred is not being widely discussed."

In Houston, senior mission controllers handling STS-107 apparently never saw the emails. They will now be turned over to the investigative board, according to spokeswoman Laura Brown.

The emails had been sought since last week by news organizations under the Freedom of Information Act. Employees at NASA's headquarters here published them Friday on the agency's Web site.

"...the equivalent of a 500-pound safe hitting the wing at 365 mph."

Among the emails were two written after the breakup. Daniel D. Mazanek of NASA's Spacecraft and Sensors Branch at Langley wrote Feb. 7 that debris striking Columbia might have been ice, not foam from the external fuel tank.

Boeing had calculated that a chunk of foam that weighed 2.67 pounds was involved. But Mazanek estimated that ice the same size would have been more damaging because it would weigh 63.4 pounds, "the equivalent of a 500-pound safe hitting the wing at 365 mph."

Last week, NASA disclosed a similar, worrisome e-mail by Daugherty. He wrote two days before Columbia's breakup about risks to the shuttle from "catastrophic" failures caused by tires possibly bursting inside the wheel compartment from extreme heat.

Daugherty was responding in that e-mail to a telephone call Jan. 27 from officials at the Johnson Space Center asking what might happen if Columbia's tires were not inflated when it attempted to land.

Three Hits Instead Of One?

In other documents released Friday, a newly disclosed Boeing report said cameras saw three large pieces of debris, each up to 20 inches long, that shattered into a shower of particles after striking Columbia along its left wing. The report, among those supporting Boeing's assurances to NASA that Columbia could return safely, was dated eight days before the spacecraft broke apart.

Earlier Boeing reports during Columbia's flight had focused on possible damage from "a large piece of debris," also about 20 inches.

NASA released three reports Friday analyzing possible damage to Columbia's insulating tiles. News organizations had previously obtained two of these. The third, dated Jan. 24, indicated the highest risk of damage was along the leading edge of Columbia's left wing, based on the speed and on the angle of the strike as the shuttle roared skyward.

Searching Nevada

Investigators are searching the area of Caliente (NV) for what could be a piece of Space Shuttle Columbia debris believed to have been tracked by air traffic control radar after it was shed early in the spacecraft's descent over California and Nevada Feb. 1.

Video imagery of Columbia's entry provided to NASA was analyzed by imagery, trajectory and ballistics experts. The results of that analysis were then provided to National Transportation Safety Board officials who reviewed air traffic control radar imagery in that area during the time of Columbia's descent. The review resulted in what is believed to be a significant radar track of a piece of debris as it fell to Earth. As a result, a search of the Caliente area near the Nevada-Utah border is under way using Civil Air Patrol assets. A search using additional means also may be forthcoming.

Similar work to narrow the possible locations of other debris believed to have been shed by Columbia above the U.S. Southwest continues, although no other areas have yet been identified for further investigation.

About 25,000 pounds of Columbia debris is now at Kennedy Space Center in Florida.  That total is about 11 percent of the orbiter's weight as it descended from orbit.  About 5,600 items from the spacecraft currently are at KSC.

The search for Columbia debris continues in Texas and Louisiana.  So far, no confirmed Shuttle debris has been found west of Granbury, Texas, near Fort Worth.

The Forest Service says more than 2,100 searchers should be in the field by Friday. They'll be a part of more than 100 teams based in Corsicana, Nacogdoches, Hemphill and Palestine, Texas.  Bad weather hampered the search on Thursday.  The search is being intensified to beat the area's spring bloom, which would make debris harder to find.

NASA Administrator Sean O'Keefe Thursday re-emphasized the Agency's intent not to launch another Space Shuttle until the cause or probable cause of the Columbia accident is found and corrected.

At a press conference from Stennis Space Center in Mississippi, O'Keefe told reporters NASA would do nothing to compromise the Agency's emphasis on safety. "Nothing I'm aware of that would suggest than anything we did should cause us to change the way we do business" in that area, he said.

NASA's position is still that there is no favorite theory about the cause of the Columbia accident. "It's all on the table," O'Keefe said in response to a reporter's question.

FMI: http://spaceflight.nasa.gov