INTERNAL emails released by NASA this week suggest that the mystery object that struck the space shuttle Columbia鈥檚 wing on lift-off may have been a heavy chunk of ice, rather than a much lighter piece of foam insulation.
The NASA engineers who wrote the emails say an ice impact could have had a far greater effect on the craft鈥檚 ability to safely re-enter the atmosphere than was thought likely in the space agency鈥檚 post-launch damage analysis.
Daniel Mazenek of NASA鈥檚 Langley Research Center in Virginia wrote that if the object caught on high-speed film was made of foam, it would have weighed about 1.2 kilograms, but if it was ice it would have weighed 29 kilograms. The energy of impact for the lighter object would be 鈥渆quivalent to a 500-pound safe impacting at 75 miles per hour鈥� 鈥� but the heavier ice would be like the same safe impacting at 365 miles per hour.
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Meanwhile, another NASA engineer, Dennis Bushnell, revealed that ongoing analysis going back to the very first shuttle launch 鈥� Columbia 鈥� showed a risk of damage to tiles from ice that regularly formed on a dumping line from a fuel tank, which he said could easily have been moved to a different position to avoid causing the tile damage. The agency 鈥渟hould have done more analysis鈥� of the problem, he wrote. 鈥淲hy this dump line was not repositioned to the other side of the orbiter I do not understand,鈥� he says.
But whatever caused any wing damage, the Columbia Accident Investigation Board was handed a fresh angle to investigate this week. A Californian newspaper reported that a group of veteran Boeing engineers, who have been involved in shuttle operations for nearly 20 years, were concerned that a less experienced team might have carried out the debris damage analyses while Columbia was in orbit 鈥� and may have seriously underestimated the severity of the launch problem.
The Orange County Register reported that the veteran group, which developed the computer software used for the evaluation, recomputed the analysis and concluded that the damage might threaten the shuttle鈥檚 safety. 鈥淭he re-analysis is finding things to be much more harsh than the original [investigation],鈥� said one of the four veteran engineers, none of whom were named.
The staffing of Boeing鈥檚 debris damage analysis team changed when 500 engineering jobs were shifted from Huntington Beach, California, to plants in Texas and Florida. The veterans told the newspaper that none of those who worked on the analysis during the mission had ever done so before. But while Boeing spokesman Glenn Golightly would not comment directly on the background of the team, he said: 鈥淲e鈥檝e got experienced people working in the programme.鈥�
While the debris analysis downplayed the risk to the flight, the released emails reveal others trying to raise the alarm. Robert Daugherty, also at Langley, was concerned about officials鈥� apparent lack of interest. 鈥淲e can鈥檛 imagine why getting information is being treated like the plague,鈥� he wrote two days before Columbia disintegrated. He was surprised managers didn鈥檛 seem interested in simulating a landing with two blown-out tyres. Yet this would have been 鈥渁s simple as hitting a software button鈥�, he wrote.