NASA goes ahead with Tuesday launch
Foam crack examined as agency prepares for Discovery mission
Monday, July 3, 2006; Posted: 10:03 p.m. EDT (02:03 GMT)
KENNEDY SPACE CENTER, Florida (CNN) -- NASA will go ahead with
Tuesday's scheduled launch of the space shuttle Discovery after
examining a pencil-sized crack in the foam insulation around the
shuttle's fuel tank, the space agency announced.
"It all looks fine, and the structure is in good shape," Associate
Administrator William Gerstenmaier told reporters.
Discovery is scheduled to lift off from Cape Canaveral at 2:37 p.m.
Tuesday. That would mark the first time a shuttle has taken off on the
Fourth of July.
The launch, already scrubbed twice due to bad weather, was threatened a
third time Monday after an inspection found a four- to five-inch crack
in the external fuel tank's foam insulation.
The cracked insulation covered a bracket that connects the liquid
oxygen feed line to shuttle Discovery's external fuel tank.
Engineers believe the problem stemmed from a buildup of frozen
condensation that crushed a small piece of foam, Deputy Program Manager
John Shannon told reporters earlier Monday.
When engineers went to inspect it, they found a .0057-pound, 3- inch
piece of foam had "pinched off."
Even so, Shannon said, had that piece fallen off during launch, it
wouldn't have damaged the orbiter.
"It turns out there is more foam on this strut than is really needed
for its intended purposes," Gerstenmaier said.
Investigators blamed a 1.6-pound piece of foam insulation falling off
the external fuel tank for the damage that caused the loss of
Discovery's sister ship Columbia. All seven astronauts aboard the
shuttle died when it broke up on re-entry over Texas in February 2003.
NASA managers huddled well into Monday evening after discovering the
problem.
"I think it would not have gotten as much attention prior to Columbia
as it is getting now," Shannon said. "I think it's a very good thing
that we have this sensitivity and that we're looking this closely at
the vehicle."
Tuesday's planned launch would be the second shuttle flight since the
Columbia disaster.
Narrow crack
The crack was discovered during an inspection Sunday evening, and is an
eighth- to a quarter-inch wide, NASA said. (Watch CNN's space expert
explain when and why the crack could have appeared -- 1:27)
The Mission Management Team met Monday morning and again in the evening
to go over possible scenarios -- including a possible fix.
For a repair, NASA would have to build a platform that would reach out
to the bracket, which would allow engineers to make the fix, according
to NASA spokesman Bruce Buckingham.
That would have taken more than a day and delayed Tuesday's launch.
But Buckingham said that still wouldn't have pushed the launch beyond a
window of time that closes July 19.
There are two concerns with the cracked foam. First, it could fall off
during launch, and the piece is close to the belly of the orbiter. The
second concern is that ice could form in the crack, causing it to
expand or the ice chunk to fall.
Weather worries
NASA postponed the launch of the shuttle Discovery on Saturday and
Sunday because of bad weather. (Full story)
Weather conditions for Tuesday give NASA a 60 percent chance of
launching. Those odds drop to 40 percent on Wednesday, according to
U.S. Air Force 1st Lt. Kaleb Nordgren.
No launch attempt was scheduled for Monday because the weather forecast
was even worse, and because NASA needed time to top off the fuel cells
that provide power while the shuttle is in orbit.
If the launch hasn't happened by July 19, the next window for the
mission will open in late August.
Those windows of opportunity are determined by the path of the orbiting
international space station, the shuttle's destination.
With each passing day, the time for a launch gets earlier by 22-1/2
minutes. That could be good news for NASA because summer thunderstorms
are less likely to be a problem earlier in the day.
Plans call for a 12-day mission to deliver supplies to the space
station and drop off European Space Agency astronaut Thomas Reiter, who
will join the Expedition 13 crew members already there.
Two astronauts, Piers Sellers and Mike Fossum, will conduct two
spacewalks, to test a new shuttle robotic arm and to repair a damaged
piece of equipment outside the space station.
They might also do a third spacewalk to test repair techniques on the
shuttle's thermal protection system. (Watch as the seven astronauts
head to the shuttle -- 5:22)
Safety concerns
NASA's decision to resume shuttle flights this summer is not without
controversy.
In the weeks leading up to the launch, two NASA officials, chief
engineer Chris Scolese and chief safety officer Bryan O'Connor, gave a
"no go" for the launch.
Program manager Wayne Hale said NASA engineers have learned a lot about
foam dynamics in the past year, but there is no way to stop the foam
from flying off the tank. (Watch as O'Connor and Scolese explain why
they are "no go" for launch -- 2:31)
Disagreements good
NASA Administrator Michael Griffin called the disagreements with the
repairs a good sign that the culture at NASA has changed. The agency
was faulted by the Columbia investigation board with having a
conformity of opinion. (Watch as astronaut Scott Kelly explains why
risk is a part of spaceflight -- 5:05)
"I personally want every engineer to express the best opinion that they
can give us," Griffin said.
He and top senior officials took into consideration O'Connor and
Scolese's concerns but concluded that if falling foam damages
Discovery, engineers will know about it, and the crew can take refuge
on the space station and wait for a rescue mission.
Griffin said he wants to fly now because the shuttle program is slated
to end in 2010 and NASA is committed to flying at least 16 missions to
complete the space station. He said he worries that delays now will
lead to dangerous schedule pressure later.
CNN's Miles O'Brien, Kate Tobin, Marcia Walton and Jason Meucci
contributed to this report.
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