Clues in shuttle's final
By Paul Recer
February 03, 2003
NASA engineers settled into their long, joyless task
of figuring out how space shuttle Columbia broke apart,
saying conditions in the shuttle's final minutes point
to a possible problem with its critical heat-protection
NASA says new evidence shows that the temperature on
Columbia's left side shot up and the ship was buffeted
by greater wind resistance before it disintegrated over
Texas, killing all seven astronauts aboard. Those
conditions forced its automatic pilot to quickly change
The combination of these events suggests that thermal
tiles may have been damaged during launch. The shuttle's
exterior is covered with thousands of tiles designed to
protect it from the extreme heat of re-entry.
Despite the possible clues, shuttle program manager
Ron Dittemore stressed yesterday that the information
was only preliminary.
"We've got some more detective work," Dittemore said.
"But we're making progress inch by inch."
While engineers at the Johnson Space Centre in
Houston analysed billions of bits of electronic data radioed to
Earth by Columbia on Saturday morning, state and federal
officials collected bits and pieces of the shattered spacecraft
over a broad swath of east Texas and Louisiana.
The debris was being catalogued and trucked to
an Air Force base in Louisiana. Some human remains also have
been recovered from the astronaut crew.
President George W Bush had arranged a meeting
today with NASA administrator Sean O'Keefe to get an update on
Computer data indicates that moments before
Columbia broke apart on Saturday on its way toward a landing in
Florida, temperatures rose in the wheel well and on the fuselage
on the left side of the shuttle.
The abnormal readings were on the same side of
the craft that was hit by peeling fuel-tank insulation during
the craft's January 16 launch, NASA engineers said.
Dittemore said engineers also were planning to
examine 32 seconds of computer data that earlier had been
ignored because it was considered flawed. The data came just
before all communications with Columbia were lost.
NASA engineers spotted the peeling fuel tank
insulation on high speed cameras that recorded the launch of
Columbia. Dittemore said the possible effects on the tiles from
the insulation were studied aggressively while the shuttle was
still aloft, but engineers concluded "it did not represent a
"As we gather more evidence, certainly the
evidence may take us in another direction," he said.
Dittemore said engineering data shows a
temperature rise of 11 to 17 degrees Celsius in the left wheel
well about seven minutes before the spacecraft's last radio
transmission. There followed a rise of about 32 degrees over
five minutes in the left hand side of the fuselage above the
wing, he said.
The shuttle temperature rose the normal eight
degrees on the right side over the same period, he said. All the
readings came from sensors underneath the thermal tiles, on the
aluminium hull of the craft.
The temperature spikes were accompanied by an
increased drag, or wind resistance, that forced Columbia's
automated flight control system to make rapid adjustments to
maintain stability. Dittemore said the corrections were the
largest ever for a shuttle re-entry, but still within the
Lockheed, the maker of the fuel tank under
scrutiny, said yesterday that NASA used an older version of the
tank, which the space agency began phasing out in 2000. NASA's
preflight press information stated the shuttle was using one of
the newer super-lightweight fuel tanks.
Harry Wadsworth, a spokesman for Lockheed, said
most shuttle launches use the "super-lightweight" tank and the
older version is no longer made. Wadsworth said he did not know
if there was a difference in how insulation was installed on the
two types of tanks.
Wadsworth said the tank used aboard the Columbia
mission was manufactured in November 2000 and delivered to NASA
the next month. Only one more of the older tanks is left, he
Dittemore said the tank, though no longer
manufactured, had been used for many years and was between
2700kg and 3150kg heavier than the newer version. Still, "we had
no reason to doubt its capability".
Earlier yesterday, O'Keefe named a former navy
admiral to oversee an independent review of the accident, and
said investigators initially would focus on whether the piece of
insulation caused the damage that brought down the shuttle.
While O'Keefe stressed that the space agency was
not locking into a single scenario of what caused the crash, the
insulation was "one of the areas we're looking at first, early,
to make sure that the investigative team is concentrating on
For a second day, searchers scoured forests and
rural areas of east Texas and western Louisiana for bits of
metal, ceramic tile, computer chips and insulation from the
State and federal officials, treating the
investigation like a multi-county crime scene, were protecting
the debris until it can be catalogued, carefully collected and
then brought to Barksdale Air Force Base in Louisiana.
The effort to reconstruct what is left of
Columbia into a rough outline of the shuttle will be tedious and