U.S. investigators are seeking every photograph and movie they can find of the disintegration of the space shuttle Columbia to help them locate debris. They are seeking pieces from the earliest stages of the orbiter's break-up.
Three weeks after the shuttle fell apart, the independent board of experts probing the disaster is still seeking hardware that fell off as the orbiter sped along its final path over the southwestern United States.
So far, 4,000 pieces have been returned to the launch site at Kennedy Space Center in Florida for examination. Ten thousand more are on their way from a Louisiana collection center. But investigating board chairman Harold Gehman says many more pieces remain undiscovered.
"Right now we have a tiny, tiny fraction of the orbiter," he said.
Investigators are especially seeking shuttle parts that were among the first to fall off on the theory that these will help pinpoint the exact location on the shuttle where the trouble began. The focus is on the shuttle's left side, where sensors showed an extreme rise in temperature during re-entry.
So far, no debris has been found west of central Texas, the point about half way across the southwestern United States where most of the shuttle broke up. But the investigating board says parts began falling off as early as Columbia's passage over California. The U.S. space agency, NASA, is asking people in states between California and Texas to be on the lookout for debris in a 200-kilometer wide zone under the shuttle's path.
As part of its hunt for parts and a cause, the investigators are analyzing images that show Columbia in its final minutes. They are screening photographs and video taken by government agencies and private space flight enthusiasts to document the shedding of parts. Mr. Gehman says his panel has pictures from as far west as an Air Force telescope in Maui, Hawaii, one of the world's most powerful that can see objects as small as a fist nearly 300 kilometers in space.
"We do have photographs from the Maui telescope and they are still being analyzed. We looked at them and we didn't see anything that jumped out at us, but it's early in the process," he said.
The videos and photographs may help determine where shuttle pieces fell. Analysts calculate the exact time and angles of the pictures by determining where the images were shot and by identifying planets or stars in the background. To predict where the parts landed, they compute probable trajectories by estimating debris properties and known atmospheric and wind data. They retrieve radar data for the area to see if it captured anything fitting the potential debris path.
Investigator John Barry, an Air Force major general, says the debris collection is tedious and will take a lot more time.
"We can't estimate right now what percentage we're going to recover. We hope we recover considerably more and it's going to be weeks and weeks and weeks when people still continue to turn in parts," he said.