Engineers raised concerns about Columbia wing burning

WASHINGTON -- One day before the Columbia disaster, senior NASA engineers worried the shuttle's left wing might burn off and cause the deaths of the crew, describing a scenario much like the one investigators believe happened.

They never sent their warnings to NASA's brass, according to dozens of pages of e-mails NASA released Wednesday.

"Why are we talking about this on the day before landing and not the day after launch?" wrote William C. Anderson, an employee for the United Space Alliance LLC, a NASA contractor, less than 24 hours before the shuttle broke apart.

Two days earlier, one frustrated engineer asked, "Any more activity today on the tile damage or are people just relegated to crossing their fingers and hoping for the best?"

After intense debate -- occurring by phone and e-mails -- the engineers, supervisors and the head of the space agency's Langley research facility in Hampton, Va., decided against taking the matter to top NASA managers.

Jeffrey V. Kling, a flight controller at Johnson Space Center's mission control, foresaw with haunting accuracy what might happen to Columbia during its fiery descent if superheated air penetrated the wheel compartment.

Kling wrote just 23 hours before the disaster that his engineering team's recommendation in such an event "is going to be to set up for a bailout ... ."

Kling the following day was among the first in mission control to report a sudden, unexplained loss of data from the shuttle's sensors in the left wing.

The e-mails describe a far broader discussion about the risks to Columbia than the concerns first raised three days earlier by Robert Daugherty, a NASA senior research engineer at Langley. He was concerned most about the safety of the shuttle landing with flat tires or wheels damaged from extreme heat.

Daugherty was responding to questions on Jan. 27 from Carlisle Campbell, a NASA engineer at Johnson Space Center, about how re-entry heat could damage the shuttle's tires. One day into the debate, Daugherty expressed frustration to Campbell about the apparent lack of interest with his remark about keeping fingers crossed.

Among the messages was one from Daugherty's boss at Langley, Mark J. Shuart, to another Langley supervisor, Doug Dwoyer, describing Daugherty as "the kind of conservative, thorough engineer that NASA needs."

One e-mail, from R.K. "Kevin" McCluney, a shuttle mechanical engineer at Johnson Space Center, described the risks that could lead to "LOCV" -- NASA shorthand for the loss of the crew and vehicle. But McCluney ultimately recommended to do nothing unless there was a "wholesale loss of data" from sensors in the left wing, in which case controllers would need to decide between a risky landing and bailout attempt.

"Beats me what the breakpoint would be between the two decisions," McCluney wrote.

Investigators have reported such a wholesale loss of sensor readings in Columbia's left wing, but it occurred too late to do anything -- after the shuttle was already racing through Earth's upper atmosphere and moments before its breakup.

NASA has considered a bailout by a shuttle crew feasible only during level, slow flight at about 20,000 feet or lower. Columbia broke up at 207,000 feet while flying 18 times the speed of sound, or roughly 12,500 miles per hour.

Many of the e-mails NASA released Wednesday were gathered at the direction of Ronald Dittemore, the shuttle's program manager at Johnson Space Center. In a message he wrote the day that news organizations first reported Daugherty's concerns, Dittemore asked for copies of the e-mails "so that I can see the traffic and get a feel for the conversations."

Daugherty's concerns -- and the following debate among other engineers -- took place days after engineers from the Boeing Co., another NASA contractor, had assured that Columbia could return safely despite possible damage to its left wing on liftoff from insulation peeling off its external fuel tank.

In response to Dittemore's request for the e-mails, Robert C. Doremus, a NASA employee at Johnson, on Feb. 11 summarized the earlier exchanges and concluded that Daugherty and three other engineers, on the afternoon before the breakup, agreed "we were doing a 'what-if' discussion and that we all expected a safe entry."

The e-mails also disclose that Dwoyer, a middle manager at Langley, wrote to the director of the research center, Del Freeman, and asked whether Freeman should contact William F. Readdy, NASA's associate administrator for space flight.

NASA officials said Wednesday that Freeman never contacted Readdy, and that Freeman considered the matter resolved after he discussed the problem with Langley engineers.