A five-day
delay in the arrival of a newly designed external tank is not expected to delay
Discovery's May 25 launch.
However, the loss of time
virtually eliminates days off for technicians, Discovery flow director
Stephanie Stilson said.
External Tank 128,
scheduled to arrive from the New Orleans factory on Thursday, was delayed by
bad weather and is now scheduled to arrive Tuesday.
The tank has titanium
brackets on the liquid oxygen feed line, soldered
ECO-sensor connectors, a redesigned ice-frost ramp and minor changes to the
metal structure.
Discovery is scheduled to
be attached to the tank and a pair of solid rocket boosters on April 27 and
then to roll out to the launch pad on May 5. That schedule leaves enough time
to load the 37-foot
Kibo science laboratory and perform last-minute checks on the spaceship and
related systems.
"We feel
confident," Stilson said.
To make room for Kibo in
the payload bay, Discovery must fly without the 540-pound orbital sensing boom
used to photograph the thermal tile to check for damage.
Endeavour, however,
borrowed Discovery's boom for its current mission and will
leave it at the International Space Station. After arriving at the space
station, Discovery will pick up the boom and use it for inspections of the
thermal tiles.
NASA's three shuttles share
two inspection booms, and Discovery is rigged so the boom it picks up in space
will work properly, Stilson said.
Discovery also has been
equipped with new radiator hoses to prevent kinks that worried managers during
Atlantis' last mission.
"We did a few cycles
of the payload door," said Stilson. "It worked exactly how we hoped
it would."
Also, Discovery's UHF radio
is working fine. NASA managers considered borrowing Discovery's radio when
Endeavour's radio would not function on its high-power mode. However, they
decided that the radio's two low-power modes would suffice.
"We don't ever like to
pull anything out of the ship," Stilson said. "If they had needed it,
by all means, we would have taken it out of Discovery."
Tuesday's arrival of the
updated external tank marks the incorporation of all the changes recommended
since the Return to Flight in 2005.
The tank, which is 153.8
feet long and 27.6 feet in diameter, carries nearly 5,000 pounds of foam, which
keeps ice from building up on the outside.
The tank modifications
include less foam on the titanium brackets that hold the liquid oxygen feed
line and modifications to foam on other parts of the tank. A piece of foam
broke loose and smashed a hole in Columbia's wing during launch on the 2003
mission that ended in disaster.
Changes to the tank will
not slow processing toward launch, Stilson said.
"I'm getting a very
clean tank when it gets here," she said.
NASA is
broadcasting Endeavour's STS-123 mission live on NASA TV. Click here for SPACE.com's
shuttle mission coverage and NASA TV feed.
Published under license
from FLORIDA TODAY. Copyright: 2008 FLORIDA TODAY. No portion of this material
may be reproduced in any way without the written consent of FLORIDA TODAY.
advertisement
