Mystery object draws interest - Shuttle Columbia;
future US 'shift changes' on ISS via Russian Soyuz
Excerpt:
HOUSTON - A mysterious object - possibly a softball-size chunk of ice - that fell off Columbia gained NASA's interest Sunday, but investigators said again that virtually nothing has been ruled out.
As the search for clues for what went wrong entered its second week in the shuttle disaster, the agency is considering a big change for the astronauts left in space.
NASA and its Russian counterpart may swap the three explorers now aboard the International Space Station for two to be launched in April aboard a Russian Soyuz vehicle.
Supplies of water, used for drinking and for producing oxygen, are running low, and the proposed crew transfer could be the best approach to get the astronauts down while the shuttle program remains on hold.
On Sunday, officials provided new details in their search for why the shuttle disintegrated, including a closer examination of parts found in Texas.
They were trying to identify the unknown object that was spotted near the shuttle one day after its Jan. 16 launch. A Department of Defense radar at Eglin Air Force Base in Florida detected a small object moving away from Columbia at around 11 mph.
NASA officials were quick to point out that the object could have been something deliberately released from the shuttle, such as discarded wastewater. But they have not ruled out that it may have been a more critical part coming loose.
"Nothing is off the table," NASA Administrator Sean O'Keefe said.