|
 |
 advertisement
| |
|
|
|
|
|
Columbia Accident Board Reveals a 'Working Hypothesis'
By Jim Banke
Senior Producer,
posted: 05:45 pm ET
06 May 2003
|
CAPE CANAVERAL, Fla. -- The pieces are face up on the table and the edge is defined, but the puzzle is far from being solved. That's the situation in which the Columbia Accident Investigation Board (CAIB) finds itself as the panel's chairman on Tuesday laid out a "working hypothesis" as to what caused the Feb. 1 loss of the shuttle and its seven-member crew. "We still have our antennae out, our senses sharpened, for any indication whatsoever that we may have it wrong or that we have overlooked something," said CAIB chairman Harold Gehman, who is a retired Navy admiral. "We reserve the right to change any part of it, anytime, without notice." Though these details have been discussed before, this was the first time the CAIB officially pronounced them to be part of the reason why Columbia was lost. "The board felt that we now know enough, and we understand enough, that it's time that we change the board's official policy -- which was we don't believe in 'scenarios of the day' or the most popular scenario -- that everything was on the table, to the point now where we believe we should focus our efforts," Gehman said. Without explaining the links between these events, or necessarily agreeing there is a link, Gehman said that the board has agreed to these facts about the Columbia tragedy:- During the Jan. 16 launch a piece of insulating foam broke free from the shuttle's external tank and struck the leading edge of Columbia's left wing.
- During the second day of the mission Earth-based tracking systems recorded evidence of a small object floating near Columbia.
- Radar followed the object for about two days until the object fell from orbit and burned up. Tests since then have determined that the object's radar signature matches two parts from the wing, but there is no conclusive proof the object came from the wing.
- Columbia and its crew worked perfectly during the 16-day mission and there is no evidence that anything struck the orbiter in space, or that the crew or payload in anyway contributed to the tragedy.
- When Columbia began its re-entry on Feb. 1, it did so with pre-existing damage to the leading edge of its left wing.
- As the spaceplane began warming up from atmospheric friction, hot gases entered the left wing and began a series of events that led to the breakup of the vehicle over Texas.
After detailing these facts, Gehman again stressed that the CAIB is not yet willing to positively link all of this together into one complete explanation of what happened. "We're careful not to say that the foam knocked a hole in the leading edge of the orbiter because we can't prove it," Gehman said. "That's not to say we don't believe that's what happened. Right now we're not willing to make that kind of statement." "I would say that the board is certainly suspicious the foam had something to do with this, but we are very careful here not to make a statement we couldn't live with," he said. With this "working hypothesis," the board's investigation will now focus on specific tests and studies that will help them write a final report, which is targeted to be complete this summer. One of the most visible tests still to come will take place in San Antonio, Texas at the Southwest Research Institute. It's there that researchers will fire samples of foam at a full-scale recreation of shuttle wing components to determine what kind of damage might occur.
|
|
|
|
|
