The length of the debris strewn from the ill-fated space shuttle Columbia Saturday could be much longer than previously thought. The U.S. space agency, NASA, says it has reports that the shuttle may have begun disintegrating as early as California, thousands of kilometers west of Texas, where most of it dispersed.
NASA has sent search teams to the far western U.S. states of California and Arizona to check reports that pieces of Columbia fell there as the orbiter was on its doomed return to Earth.
Most of the debris landed in central Texas, with some in neighboring Louisiana to the east.
A top NASA official, Michael Kostelnik, said the California and Arizona debris reports are credible and important. "Certainly, early debris early in the flight path would be critical because, obviously, that material would be near the start of the events. It would clearly be very important to see the material earliest in the sequence," he explained.
If the reports are confirmed, that would mean the disintegration spread shuttle parts across two-thirds of the continental United States.
"It's a very long, unprecedented track to deal with. So there really are few contingencies that you could compare this with. There is not a lot of experience," explained Mr. Kostelnik.
He added that the reported pieces in California and Arizona might be wing parts or insulating tiles that protect shuttles against searing re-entry heat of temperatures of 1,500 degrees Celsius or more. If so, they could help investigators determine if critical damage occurred during launch when a piece of hard foam insulation flew off a booster rocket and hit the shuttle's left wing and tiles.
The tiles and left wing have become the early focus of the accident investigation after NASA engineers found that the shuttle's left side heated to unusually high temperatures as it flew over California. That might be because of possible damage to or loss of tiles.
NASA mission control learned that foam struck the wing by viewing launch films the day after takeoff. Space agency technicians conducted an exhaustive analysis into whether wing or tile damage could have occurred. They concluded while Columbia was still in orbit that it would not affect flight safety. But they have begun to question their original finding and re-analyze their data.
Mr. Kostelnik said search teams are also in the process of recovering large, dense pieces of the shuttle that fell in Louisiana, including one or more of the engines.
So far, about 12,000 shuttle pieces have been located. The NASA official said the priority is to remove debris that might be a public hazard and to find the rest of the remains of the seven astronauts killed in the disaster. The goal, he noted, is to find all the large parts and a high percentage of the rest.
"We will do the best we can with the resources, and I think it will take weeks rather than months to get this job done," said Mr. Kostelnik.
Earlier Tuesday, a Russian rocket docked with the international space station, carrying new supplies for the three U.S. and Russian crewmembers aboard. The maneuver would normally be of little general interest, but the moratorium on shuttle flights during the Columbia probe means that supplying and switching station crews depends completely on Russian spacecraft, and that construction is on hold.
A key question is how and when to carry out the next crew exchange, which was scheduled for March. Mr. Kostelnik said a fresh team could go up in April on a Soyuz rocket, a mission that had already been scheduled to replace an existing Soyuz escape vehicle at the station. The current crew could return on the older Soyuz. But he points out that no decisions have yet been made.