This story is
Chapter 6 in an
11-part series by
Florida Today.
Michael Brieden bore
bad news. Sixteen
months after the
Columbia accident,
Brieden stood in a
conference center
meeting room, a
corporate
amphitheater of
sorts, in Ogden,
Utah.
Surrounding him that
day: Heavy hitters
from NASA
headquarters, the
American aerospace
industry, agency
field centers, an
independent
oversight group and
the Astronaut
Office.
Brieden, then lead
engineer on a
project to develop
wing panel repairs,
was center stage. He
got right to the
point.
There was no chance
NASA, by return to
flight, could
develop a way to
repair the type of
severe damage that
doomed Columbia and
its crew.
"I just laid the
dirt on the table,
and that boiled up a
conversation really
quick," said Brieden,
42. "So we had a
big, energetic
discussion on how
come Brieden
couldn't provide a
good wrap in time
for STS-114. And
that just led me
through my charts."
His PowerPoint
presentation covered
all the facts.
Engineers had worked
overtime on a
promising concept:
rigid composite
carbon over-wraps
that could be bolted
onto wing panels.
They performed as
protective skins
that could cover
holes as big as a
large pizza. But the
earliest delivery
date was late 2005,
maybe 2006. That
would stall NASA's
first post-Columbia
flight and
completion of
International Space
Station
construction.
The estimated cost
was significant:
More than $100
million to design
and manufacture a
full set for the
wing. There were
operational
challenge, too.
Forty-four wraps --
one for each unique
wing panel -- would
have to be built and
hauled to the
station to be stowed
for emergencies.
The killer was they
might not even work.
The U-shaped wraps
would fit over
damaged panels like
one taco shell over
another. But they
would jut up ever so
slightly from the
wing. Even a
minuscule rise, what
engineers call a
"step" from the
outer mold line,
would generate
excessive heat
during re-entry.
The bolts holding a
wrap in place would
melt. And the wrap
itself would melt or
fall off, exposing
the damaged panel
beneath to
temperatures up to
3,000 degrees. Hot
gas would blowtorch
through the wing.
The shuttle would be
ripped apart.
Columbia all over
again.
That day, June 9,
2004, Brieden
recommended NASA put
the concept on the
back-burner and
focus on techniques
for repairing small
holes or cracks.
Columbia had been
downed by a
1.7-pound chunk of
foam insulation that
broke free from the
shuttle's external
tank, blasting a 6-
to 10-inch hole in a
wing panel. But an
extensive effort to
redesign the tank
would preclude foam
that big from
shedding in the
future. Even in a
worst case, only
small wing panel
cracks -- or holes
less than 4 inches
in diameter -- might
have to be fixed.
And other techniques
would be used to
handle lesser
damage.
Reaction varied.
At the end of the
day, NASA leaders
decided to make
over-wraps a
long-term research
project. At least
for now, the agency
acknowledged defeat:
NASA could not fix
Columbia-like damage
any time soon.
"Nobody threw their
badge down, and I
don't think there
was even a
dissenting
position," Brieden
said.
"I think there was a
realization that we
had worked
extremely, extremely
hard on trying to
give the best answer
to the program that
we could. And there
was no doubt that we
had tapped every
talent we could.
"We didn't give it
up without a little
sorrow ourselves."
HOUSTON: Management
pushes to find
repair method
Shuttle Program
Deputy Manager Wayne
Hale tried not to
worry about the
roller coaster of
breakthroughs and
setbacks.
At the start of the
shuttle program, the
best engineers in
the world failed to
figure out a way to
have astronauts
repair heat shields
in orbit.
"They actually gave
up," Hale said.
"They didn't think
it could be solved.
Now we think we're
very close."
Even after the
Columbia accident,
some folks at NASA
were skeptical it
could be done in the
short term.
Technology might be
better, but the
shuttle and
spacesuits were
basically the same.
All told, not much
had changed.
Except one thing.
Resolve.
"You have to have
the laboratories;
you have to do the
tests," Hale said.
"All that stuff
costs money, and at
some point people
say: 'We've done
enough. We're not
going to spend any
more money. We're
just not getting
there.' "
The message from the
bosses: "Keep at
it."
CAPE CANAVERAL:
Astronauts ready to
test repair options
in space
Discovery commander
Eileen Collins was
getting anxious.
Three months before
launch, senior
managers were still
debating what repair
techniques to test
on the first
post-Columbia
mission -- the kind
of decision normally
made a year or more
earlier.
NASA had abandoned a
method for patching
wing-panel holes as
large as the one
that doomed Columbia
because ground tests
showed it probably
wouldn't work. A
complex "goo gun"
for thermal tile
repairs wasn't ready
to try on the
flight.
Time for crew
training was running
out.
"It is late,"
Collins said on a
February trip to
Kennedy Space
Center.
The crew opposed
testing the "goo
gun," which was
designed to fill
dents or gouges in
thermal tiles with
heat-resistant
material that would
harden in place.
Already clad in
cumbersome
spacesuits,
spacewalkers would
have to strap on a
bulky holding tank.
A heat-resistant red
goo would mix inside
the tank, then flow
through a 5-foot
hose before it was
squirted out of a
rifle-like metal
wand. Plus, the goo
was difficult to
apply. It didn't
stick well to tiles.
And it bubbled when
mixed, creating
voids that could
weaken a repair
patch.
"We are not going to
fly it if it's not
ready," astronaut
Steve Robinson said
at the time.
Managers decided to
keep things simple.
Side-by-side with
Robinson in the
shuttle's cargo bay,
Soichi Noguchi will
coat damaged tiles,
mounted on a sort of
workbench, with a
primer-like,
heat-resistant
material.
Dabbed on with a
device like a liquid
shoe polish
dispenser, the
"emittance wash"
will increase the
amount of heat that
damaged tiles could
reject. Robinson
will be working with
a caulk-gun and
putty knife similar
to those that can be
bought at the corner
hardware store.
He'll fill small
wing-panel cracks
with repair
material, then
smooth the damaged
area.
Inside Discovery,
the two also will
try a method for
fixing wing holes up
to 6 inches wide.
They'll paint a
sealant around
punctured panel
samples and cover
the holes with
composite carbon
patches held in
place by expanding
bolts.
All of the samples
will be brought back
to a Houston lab and
run through a
simulator to see if
they can withstand
the intense heat of
re-entry -- up to
3,000 degrees.
The goo guns won't
be tested in orbit.
But two will be
aboard Discovery
just in case.
"It's like having an
ejection seat in a
jet aircraft,"
Robinson said. "You
don't plan to use
it, but it is
there."
HOUSTON: Hardware
store provides
simple tools for
tile fix
James Reilly went to
work in a
dome-shaped vacuum
chamber at Johnson
Space Center,
testing a new wing
panel repair
technique that one
day might save a
shuttle crew.
Wearing a
full-pressure
spacesuit, the
veteran astronaut
squeezed a bead of
heat-resistant
adhesive out of a
9-inch caulk gun
onto a palette. Then
he took a standard
putty knife and
worked the substance
into a small crack,
making the surface
as smooth as
possible.
Sounds simple, like
repairing cracked
fiberglass on a
boat. And the tools
are not
sophisticated.
"It's pretty much
the same things you
would go down to
Home Depot and buy
and use in the house
to put spackling
up," Reilly said.
"That's what we
started with.
"We just went down
to the local
hardware store and
bought a bunch of
tools. And then we
started working with
them to see what we
liked and what
worked and what
didn't work."
Doing repairs in
space poses unique
problems.
First, the adhesive
bubbles up in a
vacuum, weakening
the material and
making it less
likely to survive
the intense heat of
re-entry. The repair
has to fill the
entire crack
smoothly. The
substance hardens
fast and turns into
a ceramic. Within a
few minutes, it's
too hard and stiff
to work with. The
repair "is a little
bit of an art," he
said. But it works.
Wing panel samples
that Reilly repaired
survived tests in a
NASA re-entry
simulator.
Astronauts one day
might actually have
to use the
technique. That's
because tests since
the accident have
shown that cracks as
small as
one-15,000th of an
inch -- about the
width of four
stacked pieces of
paper -- could allow
hot gas to tear into
the orbiter on the
way to the landing
strip.
"Hopefully, we never
have to use it,"
Reilly said. "But
everything that
we've done up to
this point indicates
that we can do it.
"And if I had to
ride home on it,
there's not much
choice. Give me a
ride home."
