Posted on 02/08/2003 10:51:04 PM PST by TLBSHOW
A Star-Crossed Flight
A week after the Columbia fell apart during its hurtling re-entry 39 miles up in the morning sky over Texas, the dots are not connecting for Ron Dittemore. "We are still looking for a missing link," says the 50-year-old shuttle program manager, who coordinates the initial convulsion of inquiry into the disaster. Hopes for a quick, sure explanation or even a well-rounded theory are proving as ephemeral as the multiple, spreading contrails and the thunderous roar that first mystified and then horrified witnesses on the ground.
He has bits of evidence--fuzzy photos that may show damage to the left wing as the doomed craft crossed New Mexico, a video of debris striking the wing on takeoff, a series of temperature rises and sensor failures in the shuttle's final minutes. But until it all coalesces into a clear picture, fixes will be uncertain and the three remaining shuttles are likely to remain grounded. The loss of the Challenger 17 years ago led to a 2 1/2-year flight suspension--an even more painful prospect today. The biggest practical headache: the partly finished international space station, now entirely dependent on Russian spacecraft for supplies and rotation of its three-person crews. Only shuttles can deliver the heavy pieces to keep building it.
In a melancholy chore, by week's end investigators had sent remains of several and perhaps all of the five men and two women on board Columbia to the military mortuary at Dover Air Force Base in Delaware. DNA tests are needed to be sure who is accounted for. An army of government workers delivered to Barksdale Air Force Base near Shreveport, La., the 1,000-plus pieces of debris collected so far in an area from Fort Worth to western Louisiana. They expect to find more there and--key for deciphering early stages of the accident--farther west along the path of the flight.
Out of the blue. The wreckage will eventually go to Kennedy Space Center to be reassembled as much as possible into the shape of a shuttle. From it may come clues to why a mission running so well ended so badly. Until the radio went dead at almost precisely 8 a.m. Texas time, the shuttle was on course. Its crew never hinted to ground controllers a sense of anything wrong. The craft's autopilot was keeping its nose held high, exactly at the right angle to absorb the stress of re-entry, flying a series of "S" turns to scrub off speed. "It started off as a happy morning," says NASA Administrator Sean O'Keefe. He was waiting at the runway with families of the astronauts when the landing time came and no shuttle appeared.
Almost all signs point to a failure in the left wing. In the eight minutes before communication was lost and the shuttle broke up, a cascading series of data losses from sensors there suggests spreading damage. Toward the end, the flight control computer was fighting a mysterious increase in drag on the left side, as if the wing was losing its normal shape. The computer was adjusting wing and tail flaps and even firing steering rockets to keep the shuttle on course.
The damage probably started in the shield that protects the shuttle from the searing heat of re-entry: a coating of reinforced carbon-carbon material on the wing's leading edge and a layer of brick-shaped ceramic tiles on the underside. During the shuttle's last minutes, while some sensors were failing, others recorded a mysterious temperature rise of 30 to 60 degrees in the left wheel well and along the shuttle's left side. That heating was relatively small. But elsewhere in the wing, away from working sensors, the heat shield could have been breached, letting superheated gas burn its way into the wing. That could have melted aluminum, cut hydraulics, or wrought enough other aerodynamic and mechanical havoc to cause the ship to fly out of control and break up.
Ground truth? Just as the first sensors were failing, witnesses including astronomers in the Owens Valley of eastern California saw glowing motes falling from the shuttle as it ripped through the predawn sky. And Aviation Week reported last Friday that in telescope images from the Air Force's Starfire Optical Range in New Mexico, the shuttle's left wing appears jagged along its leading edge. NASA is studying the images, but late Friday, Dittemore showed one coarse frame at a press conference and called it "not tremendously revealing to us yet."
What investigators now need is specific evidence of an accident, design flaw, human error, or anything else that could have caused the initial damage to the heat shield, leading to the snowballing disaster during re-entry. Within hours of the accident, they had zeroed in on a briefcase-size chunk of insulating foam that was seen by Kennedy Space Center cameras peeling off the shuttle's big, throwaway external fuel tank 80 seconds after launch January 16. It seems to a layman's eye the perfect suspect. Swept onto the rising rocket at 500 mph, the hunk glanced off the left wing, disintegrating into a dramatic, bright burst of particles.
Such debris often strikes shuttle orbiters during launch. After a shuttle lands, ground crews typically find 100 or so small dings in the black tiles on its belly--most suffered during launch. But this was the biggest piece anybody ever saw whack a shuttle. So during the mission, while the crew pursued dozens of science experiments in a payload bay lab, engineers on the ground analyzed the film extensively and used computer modeling to learn what the wayward material might have done.
Their conclusion: The damage would have been inconsequential. Layers of upper-level managers reviewed the report and agreed. NASA's analysts dismissed speculation that the foam might have been weighed down with ice that formed when the tank was filled with superchilled liquid hydrogen and oxygen. A prelaunch inspection found no sign of ice, and NASA said none could have formed in or under the impermeable foam. "Right now, it just does not make sense to us that this piece of debris would be the root cause for the loss of Columbia and crew," Dittemore said at midweek. "There's got to be another reason."
The falling-insulation theory isn't dead. But it now is just one of many competing hypotheses. They include the slight chance of terrorist sabotage to a flight carrying Israel's first astronaut, Ilan Ramon; faulty installation of one or more tiles; damage from orbiting space junk; or a meteoroid strike. It would be a freak accident, but at a relative speed of 20,000 mph, even a pea-size object could "go clean through the wing," said physicist Patricia Reiff, director of the Rice University Space Institute. "It could be devastating." Over the commotion of the shuttle's fans and pumps, the crew might not hear or feel such a hit.
Or it could be something few had imagined. Late in the week, an amateur astronomer in San Francisco turned over to NASA his digital photos showing a strange, purplish zigzag line intersecting the shuttle's trail, which widens at that point as if the ship had been damaged. Reports of the photo, not yet made public, led to speculation that a strange upper atmospheric electrical event could have ambushed the shuttle. At last word, NASA was unsure if the image shows something in the sky or just a camera glitch.
NASA continually vows that safety is its top priority. But its latest official calculation of shuttle safety, summing up chances of failure by systems or people, puts the odds that a shuttle and crew will be lost at 1 in every 265 launches. In fact, two shuttles have been lost in 113 launches, one for every 56.5 launches. That's a 98.2 percent success rate. In 2001 NASA Associate Administrator Bill Readdy told a congressional shuttle-safety panel that for flying people in space, "95 percent or even 99 percent does not get an A. It gets an F."
There will be no shortage of people and committees giving their own grades. NASA boss O'Keefe appointed a panel of outside experts, led by retired Adm. Harold Gehman (box), to oversee Dittemore's probe and reach conclusions. Unsure that the panel could be fully independent, some members of Congress are calling for a higher-level panel, like the Challenger commission appointed by Ronald Reagan and led by former Secretary of State William P. Rogers. This week Congress will start taking testimony, with NASA head man O'Keefe on the witness list.
Hard questions may also come Congress's way. NASA blames tight budgets for repeatedly delaying or canceling some upgrades to the shuttles, including Columbia, which first flew more than 20 years ago. Items scratched from NASA's wish list include new, more easily controlled liquid-fueled boosters and onboard power generators that don't use the dangerous, explosive hydrazine fuel now employed. Meanwhile, NASA's workforce has been aging and shrinking.
Reassessment. The accident left some wondering whether human spaceflight is worth the cost and danger. Alex Roland, a Duke University historian, acknowledges that people are intoxicated by space but says, "We don't have anything to do up there." Many researchers agree that the science done by astronauts is marginal compared with returns from automated Mars rovers, space telescopes, and satellites.
Others say NASA will never walk away from human spaceflight. "NASA can't even think about it," says George Washington University space analyst Ray Williamson. Without people in spacesuits, public support for the rest of NASA may shrivel. "The question is, can we maintain human space flight on the cheap?"
Beyond questions of politics and research is the romance of spaceflight, still alive more than 30 years after the moon landings. The day after the accident, a Gallup Poll showed that 82 percent of Americans want NASA to keep sending people into space, nearly the same as the 80 percent found after the Challenger loss. In a memorial service for Columbia's crew, President Bush agreed. "America's space program will go on. This cause of exploration and discovery is not an option we choose; it is a desire written in the human heart."
With Samantha Levine, Julian E. Barnes, Thomas Hayden and Douglas Pasternak
The shuttle was far too high above the earth for a terrorist missle strike...
But...
Our work places---particularly those work places of skilled, particularly technical and engineering and computer work environments---are populated by tens of thousands of foreigners who a) owe no allegiance to the U.S., and/or b) personally ascribe to the beliefs of our enemies that we must be destroyed.
These people are ON THE INSIDE. I know what they could do to a typical Fortune 500 company in the transportation or manufacturing or telecommunications biz...Imagine what they could do in sabotaging an aircraft or spacecraft? ...
Whether this scenario applies to the Columbia or not, it is something we'd better be keenly aware of as we proceed into the uncertain future of securing our nation.
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