The Columbia Accident Investigation Board has said preliminary analysis by a NASA working group indicates the temperature indications seen in Columbia's left wheel well during entry would require the presence of a plasma leak. Plasma is a super heated gas surrounding the orbiter during re-entry. The CAIB said heat transfer through the structure, as from a missing tile, would not be sufficient to cause the temperature indications seen in the last minutes of flight. Additional analysis is under way, including into the possibility of a supsected plasma leak.
Plasma can reach temperatures in the range of 2500 degrees Fahrenheit, while the melting point of aluminum is around 900 degrees. However, experts at NASA say that the loss of a single tile would not be sufficient to allow the plasma to melt its way into the wing.
Although there was an indication of the left landing gear being extended, other sensors provided different information. NASA Controllers say that had the landing gear actually been deployed, the drag caused by such an event would have made the shut flight much more erratic than it was prior to the breakup.
The search continues in the western United States for debris from Columbia. As of early February 13, no debris found farther west than Granbury, Texas, about 40 miles southwest of Fort Worth, had been confirmed as Shuttle-related. The first two trucks containing debris from Columbia arrived at NASA Kennedy Space Center (KSC), Fla. the morning of February 12.
The Federal Emergency Management Agency (FEMA) reported today the Shuttle debris recovery operation is proceeding well. FEMA said 72 percent of sites in Texas and 84 percent of sites in Louisiana have been cleared.
Full Size Images:
