Posted on Sun, Jul. 31, 2005
Ref: http://www.contracostatimes.com/mld/cctimes/news/nation/12269385.htm

Old maxim didn't apply to NASA's foam problem
By John Schwartz
NEW YORK TIMES

"We are ready to fly."

Posted on Sun, Jul. 31, 2005
Ref: http://www.contracostatimes.com/mld/cctimes/news/nation/12269385.htm

Old maxim didn't apply to NASA's foam problem
By John Schwartz
NEW YORK TIMES

"We are ready to fly."

It was June 24, and William Parsons, NASA's shuttle
program manager, was speaking to reporters on a
conference call from the Kennedy Space Center at
Cape Canaveral, Fla.

Two-and-a-half years of study and struggle, he told
them, were over at long last.

The shuttle Discovery could blast off in July.

At a meeting that day, shuttle managers had ruled
that the chances that debris from the external fuel
tank would strike the Discovery at liftoff -- in
the kind of accident that doomed the Columbia and
its crew in 2003 -- had been reduced to "acceptable
levels."

Posted on Sun, Jul. 31, 2005
Ref: http://www.contracostatimes.com/mld/cctimes/news/nation/12269385.htm

Old maxim didn't apply to NASA's foam problem
By John Schwartz
NEW YORK TIMES

"We are ready to fly."

It was June 24, and William Parsons, NASA's shuttle
program manager, was speaking to reporters on a
conference call from the Kennedy Space Center at
Cape Canaveral, Fla.

Two-and-a-half years of study and struggle, he told
them, were over at long last.

The shuttle Discovery could blast off in July.

At a meeting that day, shuttle managers had ruled
that the chances that debris from the external fuel
tank would strike the Discovery at liftoff -- in
the kind of accident that doomed the Columbia and
its crew in 2003 -- had been reduced to "acceptable
levels."

The possibility that a large chunk of insulating
foam might break away from a section of the tank
called the protuberance air load ramp, or PAL,
never came up.

It had been ruled out months earlier, checked off
on a long list of items no longer worthy of concern
or of urgent action.

Last Tuesday, NASA's view that it had produced the
safest fuel tank in shuttle history was shattered
two minutes into the flight of the Discovery. Two
spacewalking astronauts tested repair techniques
Saturday.

The 0.9-pound piece of foam that fell from the PAL
ramp on liftoff, which could have led to another
catastrophe if it had ripped away a minute sooner,
forced the immediate suspension of future shuttle
flights until the problem could be resolved.

How did it happen? An examination of the efforts to
resolve the PAL ramp issues reveals a succession of
missed opportunities and dubious judgments, not
just in the two-and-a-half years since the Columbia
disaster but over the life of the program.

Potentially useful tests were not performed.
Innovative solutions were not seriously pursued.
Tantalizing clues were missed.

In the end, the old engineering maxim "If it ain't
broke, don't fix it" trumped misgivings about a
part that had not shed any foam, as far as anyone
knew, since 1983.

"After two-and-a-half years, they should have been
able to fix the foam," said Paul Czysz, a professor
emeritus of aeronautical engineering at St. Louis
University and a veteran consultant to NASA.

Now, with the future of the International Space
Station in the balance and the shuttle fleet just
five years away from a mandatory retirement imposed
by President Bush, NASA is still trying.

In the dawn of the shuttle program, NASA rules said
no foam at all should be allowed to hit the shuttle
and possibly damage the fragile heat-resistant
tiles that cover its aluminum skin.

But fidelity to those standards was relaxed over
time; in fact, foam fell off of the PAL ramp in two
early missions, including the one in June 1983 on
which Sally Ride became the first U.S. woman in
space.

There may have been many more incidents, but dozens
of shuttle missions have been launched at night
with no visual record of foam, and the tanks
themselves are at the bottom of the ocean.

As the early tank was replaced with two lighter
successors, the PAL ramps remained -- one a 19-foot
baffle along a channel for cables and pressurized
lines along the forward end of the tank and the
other a 37-foot strip along the flank of the
cylindrical midsection of the fuel tank.

And as experience showed NASA that shuttles
returned safely despite more than 100 nicks and
gouges requiring repair on many flights, the
concerns abated over time.

Until Feb. 1, 2003, the day the Columbia
disintegrated on its way home to Cape Canaveral.

After the accident, NASA examined all possible
sources of liftoff debris, eventually identifying
more than 170.

The PAL ramp became a focus of attention: Like the
bipod arm ramp, the part of the tank implicated in
the Columbia disaster, it is covered with foam by
hand.

NASA conducted extensive wind-tunnel tests to
determine whether the ramp could be removed.

The tests of the ramp areas were all focused on
aerodynamics -- helping determine how air would
flow around the craft and tank, or to improve
understanding of where foam or ice or other debris
might fly should it fall free of the tank.

But there were no tests of the PAL foam itself at
speeds, pressures or vibrations experienced during
ascent.

So the only tests of how the material might hold up
under the rigor of launching were the launchings
themselves, with crew aboard.

For many aeronautical engineers, a central rule in
developing an aircraft is taking its components
beyond the breaking point.

Michael Griffin, NASA's new administrator and an
engineer, said Friday, engineers believe, "If it
ain't broke, don't fix it."

"We debated and discussed whether the PAL ramp was
broken" in the months that followed the Columbia
disaster, Griffin continued.

"The conclusion we came to was the wrong one, but
the conclusion we came to after considerable study
was that it was better to fly as is."

NASA engineers had already seen how fixes can break
things.

After they made a minor change in the foam
application process in the late 1990s to comply
with environmental rules, small divots of foam
rained off of the tank during ascent.

The phenomenon, called popcorning, was caused by
trapped bubbles; NASA solved the problem by venting
the foam with tiny holes, but it was a reminder, if
any was needed, that seemingly small changes can
have profound effects.

Ultimately, the accident board recommended that
NASA find ways to prevent any shedding of foam or
other debris. And NASA gained confidence during the
time between flights that it was making progress.

Among other things, it improved the training
processes for applying foam by hand.

At the Michoud tank assembly plant in Louisiana, an
observer monitors every worker spraying foam --
"for every sprayer there's a watcher, a second pair
of eyes," said June Malone, a NASA spokeswoman.

But the tank that flew with the Discovery last week
was made before the new procedures went into
effect, and NASA stopped short of requiring that
the ramps be redone, said a spokesman, Martin
Jensen.

After the Columbia accident board issued its
scathing report on the causes of the disintegration
-- especially a "broken safety culture" at NASA
that had grown complacent about all sorts of risks
-- another independent group was set up to monitor
NASA's progress in fulfilling the accident board's
recommendations.

That group, called the Stafford-Covey task force
after the two former astronauts who led it,
accepted NASA's argument that the PAL ramp did not
urgently require alteration.

At its final meeting in June, however, it also
found that NASA had failed to meet the goal of
eliminating all debris.

The group took issue with the way NASA determined
that the foam chunks that might still fall off the
tank were too small to cause critical damage.

And it criticized NASA's tendency to depend on
computer simulations when physical experiments
might yield more valuable data.

Ultimately, however, the group accepted NASA's
contention that it had raised the level of safety
in general.

A NASA engineer who works on tank safety issues
said other areas of foam shedding from the
Discovery's tank were even more troubling than the
PAL ramp loss -- especially a divot that popped
from the vicinity of the left-hand bipod strut, the
spot that shed the foam that brought down Columbia.

The loss of foam from that spot after so much work
to correct the problem, he went on, proves that the
problem is still far more complex than NASA
understands.

So the space agency is back to the drawing board.

Copyright (c) 2005 New York Times

Posted on Sun, Jul. 31, 2005
Ref: http://www.contracostatimes.com/mld/cctimes/news/nation/12269385.htm

Old maxim didn't apply to NASA's foam problem

Posted on Sun, Jul. 31, 2005
Ref: http://www.contracostatimes.com/mld/cctimes/news/nation/12269385.htm

Old maxim didn't apply to NASA's foam problem
By John Schwartz
NEW YORK TIMES

"We are ready to fly."

At a meeting that day, shuttle managers had ruled
that the chances that debris from the external fuel
tank would strike the Discovery at liftoff -- in
the kind of accident that doomed the Columbia and
its crew in 2003 -- had been reduced to "acceptable
levels."

In the end, the old engineering maxim "If it ain't
broke, don't fix it" trumped misgivings about a
part that had not shed any foam, as far as anyone
knew, since 1983.

"After two-and-a-half years, they should have been
able to fix the foam," said Paul Czysz, a professor
emeritus of aeronautical engineering at St. Louis
University and a veteran consultant to NASA.

Now, with the future of the International Space
Station in the balance

and the shuttle fleet just
five years away from a mandatory retirement imposed
by President Bush, NASA is still trying.

So the space agency is back to the drawing board.

Posted on Sun, Jul. 31, 2005
Ref: http://www.contracostatimes.com/mld/cctimes/news/nation/12269385.htm

Old maxim didn't apply to NASA's foam problem
By John Schwartz
NEW YORK TIMES

"We are ready to fly."

It was June 24, and William Parsons, NASA's shuttle
program manager, was speaking to reporters on a
conference call from the Kennedy Space Center at
Cape Canaveral, Fla.

Two-and-a-half years of study and struggle, he told
them, were over at long last.

The shuttle Discovery could blast off in July.

At a meeting that day, shuttle managers had ruled
that the chances that debris from the external fuel
tank would strike the Discovery at liftoff -- in
the kind of accident that doomed the Columbia and
its crew in 2003 -- had been reduced to "acceptable
levels."

The possibility that a large chunk of insulating
foam might break away from a section of the tank
called the protuberance air load ramp, or PAL,
never came up.

It had been ruled out months earlier, checked off
on a long list of items no longer worthy of concern
or of urgent action.

Last Tuesday, NASA's view that it had produced the
safest fuel tank in shuttle history was shattered
two minutes into the flight of the Discovery. Two
spacewalking astronauts tested repair techniques
Saturday.

The 0.9-pound piece of foam that fell from the PAL
ramp on liftoff, which could have led to another
catastrophe if it had ripped away a minute sooner,
forced the immediate suspension of future shuttle
flights until the problem could be resolved.

How did it happen? An examination of the efforts to
resolve the PAL ramp issues reveals a succession of
missed opportunities and dubious judgments, not
just in the two-and-a-half years since the Columbia
disaster but over the life of the program.

Potentially useful tests were not performed.
Innovative solutions were not seriously pursued.
Tantalizing clues were missed.

In the end, the old engineering maxim "If it ain't
broke, don't fix it" trumped misgivings about a
part that had not shed any foam, as far as anyone
knew, since 1983.

"After two-and-a-half years, they should have been
able to fix the foam," said Paul Czysz, a professor
emeritus of aeronautical engineering at St. Louis
University and a veteran consultant to NASA.

Now, with the future of the International Space
Station in the balance and the shuttle fleet just
five years away from a mandatory retirement imposed
by President Bush, NASA is still trying.

In the dawn of the shuttle program, NASA rules said
no foam at all should be allowed to hit the shuttle
and possibly damage the fragile heat-resistant
tiles that cover its aluminum skin.

But fidelity to those standards was relaxed over
time; in fact, foam fell off of the PAL ramp in two
early missions, including the one in June 1983 on
which Sally Ride became the first U.S. woman in
space.

There may have been many more incidents, but dozens
of shuttle missions have been launched at night
with no visual record of foam, and the tanks
themselves are at the bottom of the ocean.

As the early tank was replaced with two lighter
successors, the PAL ramps remained -- one a 19-foot
baffle along a channel for cables and pressurized
lines along the forward end of the tank and the
other a 37-foot strip along the flank of the
cylindrical midsection of the fuel tank.

And as experience showed NASA that shuttles
returned safely despite more than 100 nicks and
gouges requiring repair on many flights, the
concerns abated over time.

Until Feb. 1, 2003, the day the Columbia
disintegrated on its way home to Cape Canaveral.

After the accident, NASA examined all possible
sources of liftoff debris, eventually identifying
more than 170.

The PAL ramp became a focus of attention: Like the
bipod arm ramp, the part of the tank implicated in
the Columbia disaster, it is covered with foam by
hand.

NASA conducted extensive wind-tunnel tests to
determine whether the ramp could be removed.

The tests of the ramp areas were all focused on
aerodynamics -- helping determine how air would
flow around the craft and tank, or to improve
understanding of where foam or ice or other debris
might fly should it fall free of the tank.

But there were no tests of the PAL foam itself at
speeds, pressures or vibrations experienced during
ascent.

So the only tests of how the material might hold up
under the rigor of launching were the launchings
themselves, with crew aboard.

For many aeronautical engineers, a central rule in
developing an aircraft is taking its components
beyond the breaking point.

Michael Griffin, NASA's new administrator and an
engineer, said Friday, engineers believe, "If it
ain't broke, don't fix it."

"We debated and discussed whether the PAL ramp was
broken" in the months that followed the Columbia
disaster, Griffin continued.

"The conclusion we came to was the wrong one, but
the conclusion we came to after considerable study
was that it was better to fly as is."

NASA engineers had already seen how fixes can break
things.

After they made a minor change in the foam
application process in the late 1990s to comply
with environmental rules, small divots of foam
rained off of the tank during ascent.

The phenomenon, called popcorning, was caused by
trapped bubbles; NASA solved the problem by venting
the foam with tiny holes, but it was a reminder, if
any was needed, that seemingly small changes can
have profound effects.

Ultimately, the accident board recommended that
NASA find ways to prevent any shedding of foam or
other debris. And NASA gained confidence during the
time between flights that it was making progress.

Among other things, it improved the training
processes for applying foam by hand.

At the Michoud tank assembly plant in Louisiana, an
observer monitors every worker spraying foam --
"for every sprayer there's a watcher, a second pair
of eyes," said June Malone, a NASA spokeswoman.

But the tank that flew with the Discovery last week
was made before the new procedures went into
effect, and NASA stopped short of requiring that
the ramps be redone, said a spokesman, Martin
Jensen.

After the Columbia accident board issued its
scathing report on the causes of the disintegration
-- especially a "broken safety culture" at NASA
that had grown complacent about all sorts of risks
-- another independent group was set up to monitor
NASA's progress in fulfilling the accident board's
recommendations.

That group, called the Stafford-Covey task force
after the two former astronauts who led it,
accepted NASA's argument that the PAL ramp did not
urgently require alteration.

At its final meeting in June, however, it also
found that NASA had failed to meet the goal of
eliminating all debris.

The group took issue with the way NASA determined
that the foam chunks that might still fall off the
tank were too small to cause critical damage.

And it criticized NASA's tendency to depend on
computer simulations when physical experiments
might yield more valuable data.

Ultimately, however, the group accepted NASA's
contention that it had raised the level of safety
in general.

A NASA engineer who works on tank safety issues
said other areas of foam shedding from the
Discovery's tank were even more troubling than the
PAL ramp loss -- especially a divot that popped
from the vicinity of the left-hand bipod strut, the
spot that shed the foam that brought down Columbia.

The loss of foam from that spot after so much work
to correct the problem, he went on, proves that the
problem is still far more complex than NASA
understands.

So the space agency is back to the drawing board.

Copyright (c) 2005 New York Times

Posted on Sun, Jul. 31, 2005
Ref: http://www.contracostatimes.com/mld/cctimes/news/nation/12269385.htm

Old maxim didn't apply to NASA's foam problem
By John Schwartz
NEW YORK TIMES

"We are ready to fly."

It was June 24, and William Parsons, NASA's shuttle
program manager, was speaking to reporters on a
conference call from the Kennedy Space Center at
Cape Canaveral, Fla.

Two-and-a-half years of study and struggle, he told
them, were over at long last.

The shuttle Discovery could blast off in July.

At a meeting that day, shuttle managers had ruled
that the chances that debris from the external fuel
tank would strike the Discovery at liftoff -- in
the kind of accident that doomed the Columbia and
its crew in 2003 -- had been reduced to "acceptable
levels."

The possibility that a large chunk of insulating
foam might break away from a section of the tank
called the protuberance air load ramp, or PAL,
never came up.

It had been ruled out months earlier, checked off
on a long list of items no longer worthy of concern
or of urgent action.

Last Tuesday, NASA's view that it had produced the
safest fuel tank in shuttle history was shattered
two minutes into the flight of the Discovery. Two
spacewalking astronauts tested repair techniques
Saturday.

The 0.9-pound piece of foam that fell from the PAL
ramp on liftoff, which could have led to another
catastrophe if it had ripped away a minute sooner,
forced the immediate suspension of future shuttle
flights until the problem could be resolved.

How did it happen? An examination of the efforts to
resolve the PAL ramp issues reveals a succession of
missed opportunities and dubious judgments, not
just in the two-and-a-half years since the Columbia
disaster but over the life of the program.

Potentially useful tests were not performed.
Innovative solutions were not seriously pursued.
Tantalizing clues were missed.

In the end, the old engineering maxim "If it ain't
broke, don't fix it" trumped misgivings about a
part that had not shed any foam, as far as anyone
knew, since 1983.

"After two-and-a-half years, they should have been
able to fix the foam," said Paul Czysz, a professor
emeritus of aeronautical engineering at St. Louis
University and a veteran consultant to NASA.

Now, with the future of the International Space
Station in the balance and the shuttle fleet just
five years away from a mandatory retirement imposed
by President Bush, NASA is still trying.

In the dawn of the shuttle program, NASA rules said
no foam at all should be allowed to hit the shuttle
and possibly damage the fragile heat-resistant
tiles that cover its aluminum skin.

But fidelity to those standards was relaxed over
time; in fact, foam fell off of the PAL ramp in two
early missions, including the one in June 1983 on
which Sally Ride became the first U.S. woman in
space.

There may have been many more incidents, but dozens
of shuttle missions have been launched at night
with no visual record of foam, and the tanks
themselves are at the bottom of the ocean.

As the early tank was replaced with two lighter
successors, the PAL ramps remained -- one a 19-foot
baffle along a channel for cables and pressurized
lines along the forward end of the tank and the
other a 37-foot strip along the flank of the
cylindrical midsection of the fuel tank.

And as experience showed NASA that shuttles
returned safely despite more than 100 nicks and
gouges requiring repair on many flights, the
concerns abated over time.

Until Feb. 1, 2003, the day the Columbia
disintegrated on its way home to Cape Canaveral.

After the accident, NASA examined all possible
sources of liftoff debris, eventually identifying
more than 170.

The PAL ramp became a focus of attention: Like the
bipod arm ramp, the part of the tank implicated in
the Columbia disaster, it is covered with foam by
hand.

NASA conducted extensive wind-tunnel tests to
determine whether the ramp could be removed.

The tests of the ramp areas were all focused on
aerodynamics -- helping determine how air would
flow around the craft and tank, or to improve
understanding of where foam or ice or other debris
might fly should it fall free of the tank.

But there were no tests of the PAL foam itself at
speeds, pressures or vibrations experienced during
ascent.

So the only tests of how the material might hold up
under the rigor of launching were the launchings
themselves, with crew aboard.

For many aeronautical engineers, a central rule in
developing an aircraft is taking its components
beyond the breaking point.

Michael Griffin, NASA's new administrator and an
engineer, said Friday, engineers believe, "If it
ain't broke, don't fix it."

"We debated and discussed whether the PAL ramp was
broken" in the months that followed the Columbia
disaster, Griffin continued.

"The conclusion we came to was the wrong one, but
the conclusion we came to after considerable study
was that it was better to fly as is."

NASA engineers had already seen how fixes can break
things.

After they made a minor change in the foam
application process in the late 1990s to comply
with environmental rules, small divots of foam
rained off of the tank during ascent.

The phenomenon, called popcorning, was caused by
trapped bubbles; NASA solved the problem by venting
the foam with tiny holes, but it was a reminder, if
any was needed, that seemingly small changes can
have profound effects.

Ultimately, the accident board recommended that
NASA find ways to prevent any shedding of foam or
other debris. And NASA gained confidence during the
time between flights that it was making progress.

Among other things, it improved the training
processes for applying foam by hand.

At the Michoud tank assembly plant in Louisiana, an
observer monitors every worker spraying foam --
"for every sprayer there's a watcher, a second pair
of eyes," said June Malone, a NASA spokeswoman.

But the tank that flew with the Discovery last week
was made before the new procedures went into
effect, and NASA stopped short of requiring that
the ramps be redone, said a spokesman, Martin
Jensen.

After the Columbia accident board issued its
scathing report on the causes of the disintegration
-- especially a "broken safety culture" at NASA
that had grown complacent about all sorts of risks
-- another independent group was set up to monitor
NASA's progress in fulfilling the accident board's
recommendations.

That group, called the Stafford-Covey task force
after the two former astronauts who led it,
accepted NASA's argument that the PAL ramp did not
urgently require alteration.

At its final meeting in June, however, it also
found that NASA had failed to meet the goal of
eliminating all debris.

The group took issue with the way NASA determined
that the foam chunks that might still fall off the
tank were too small to cause critical damage.

And it criticized NASA's tendency to depend on
computer simulations when physical experiments
might yield more valuable data.

Ultimately, however, the group accepted NASA's
contention that it had raised the level of safety
in general.

A NASA engineer who works on tank safety issues
said other areas of foam shedding from the
Discovery's tank were even more troubling than the
PAL ramp loss -- especially a divot that popped
from the vicinity of the left-hand bipod strut, the
spot that shed the foam that brought down Columbia.

The loss of foam from that spot after so much work
to correct the problem, he went on, proves that the
problem is still far more complex than NASA
understands.

So the space agency is back to the drawing board.

Copyright (c) 2005 New York Times