Four solid-rocket booster segments
riding near the front of the freight train that derailed May 2 in Alabama are
headed back to Utah where their manufacturer, Alliant Techsystems (ATK), will
either use them for ground tests or thoroughly refurbish them.
George Torres, a spokesman for
Magna, Utah-based ATK Launch Systems Group, said May 9 that NASA and ATK
determined over the weekend of May 5-6 that the four booster segments riding
toward the back of the train are probably still fit for flight and so will
continue on to Florida. Once the booster segments arrive at Kennedy Space
Center, they will undergo extensive inspection before NASA approves their use
for an upcoming space shuttle mission.
NASA and ATK officials said the
freight train was traveling under 4.7 miles (six kilometers) per hour when the raised
roadbed it was crossing collapsed, causing the front of the train to go off the
tracks. The two locomotives fell onto their sides, pulling a passenger car
with them, injuring six people. Four booster-carrying flatbed cars toward the
front of the train also derailed, with one falling
over onto its side. The other four boosters were on cars toward the back of
the train and remained upright and on the tracks during the accident, the cause
of which is still under investigation.
June Malone, a spokeswoman for NASA
Marshall Space Flight Center in Huntsville, Ala., said data recorders on board
the train to monitor ride conditions found that only the four boosters near the
front of the train were jostled hard enough in the accident to disqualify them
for flight.
"We have accelerometers on those
cars," Malone said. "The four in the front have acceleration data outside of
the guidelines. The four in the back were within the guideline."
Torres said the four boosters cleared to travel
on to Florida were back in transit May 9 and were expected to reach Kennedy
Space Center May 14.
"Once we get them there we will do
additional extensive analysis, including X-ray and anything we can do to be
absolutely sure they are OK," Torres said.
Four booster segments comprise a
single 149-foot (45-meter) tall booster, two of which are needed to help the
space shuttle lift off. Approximately two minutes into flight, the boosters are
jettisoned, recovered from the ocean and sent back to ATK to be flushed and
filled with new solid propellant, a hard rubber-like material called ammonium
perchlorate.
Torres said the eight boosters ATK
loaded on to the train April 27 for what was supposed to be no longer than a
two-week trip were designated for shuttle missions slated for
October and December.
Malone and Torres both said the
derailment would not delay upcoming shuttle flights. The shuttle's next liftoff
is slated for June 8.
"We have two full sets that are
completed for missions next spring and next summer that we could move up and
basically swap them out," Torres said. "We don't see an impact to flight rate
since we have these already completed."
Torres said the four boosters being
sent back to ATK's manufacturing facility in Promontory, Utah, could be used in
ground tests pending the outcome of planned inspections.
ATK conducts horizontal ground tests
of shuttle boosters twice a year, usually once in the spring and once in the
fall. The next such static fire is scheduled for May 24, according to Torres.
If ATK decides against firing the
boosters involved in the accident, Torres said they would be flushed and
refilled just like a spent booster recovered after a shuttle launch.
"The cases themselves are reusable
regardless," Torres said.
