The Columbia Accident Investigation Board will cite
serious deficiencies in NASA's overall safety program
as a root cause or significant contributing factor to
the loss of the space shuttle Columbia and her crew.
Investigators believe these deficiencies involve a
lack of effectiveness about how NASA has carried out
the government's responsibility
for broader oversight, when it transferred more
specific vehicle quality control duties to the United
Space Alliance (USA) under the Space Flight Operations
Contract (SFOC).
That will be a significant part of the Board's
report," said accident board chairman Adm. (ret)
Harold W. Gehman.
NASA will come in for greater criticism than the
contractor and NASA's role will likely draw sharp
Congressional and Bush administration interest.
The board
has conducted about 60 interviews with line
technicians in United Space Alliance all the way up
through mid-level and senior management at NASA and
USA. "And not a single person has said that the
quality program is at 100% where it ought to be,"
said an investigator familiar with those interviews.
Another major problem is that investigators have
found "there is no automatic program review" required
periodically of NASA's own safety program performance.
"If someone sees something they raise their hand,
but there is no overall 'step back to look at
performance' to address what we are not doing that we
should be doing," an investigator said.
An overemphasis or inappropriate reliance on
International Standards Organization ISO 9000
processes is also a problem.
"Simply said, some things that work great for an
airline industry that has thousands of flights per
week may not be right for a research and development
manned space system with only 113 flights under its
belt," said board member USAF Brig. Gen. Duane Deal,
commander of the 21st Space Wing at Peterson AFB, Col.
He said NASA has "moved toward some things that are
in line with ISO 9000 and some operations where you
are doing 'sampling' versus a continual look at
something that only flies once or twice per year. We
are looking very heavily at that, whether that is the
right answer for a program like this," Deal said in
Houston last week.
Gehman said that rather than safety being
stiffened, safety margins on the shuttle have been
eroding over the last several years. "We are going to
try and restore those safety margins at least back to
where we are comfortable with them."
NASA's own internal post-Columbia-accident reviews
have also begun to reveal details on past
safety-related issues that did not result in
incidents, but could have. Those are being uncovered
as part of a broad initiative begun in mid-March by
former astronaut William Readdy, NASA associate
administrator for space flight (AW&ST Mar. 24, p. 36).
In one case, the program failed to replace a
Criticality-1-related component that had been showing
anomalous behavior. The component in fact did fail
during the launch of STS-112 last October, but a
redundant system prevented a catastrophe.
The assessment involves a large launch pad cable
that carries vital commands for the separation of
solid rocket booster hold-down bolts and the
retraction of the desk-sized "T-zero umbilicals" that
pull out of the orbiter's side at booster ignition.
There are two redundant cables that are both
supposed to carry the commands, but during the Oct. 7,
2002, launch of Atlantis on the STS-112 mission, only
one of those cables carried the critical
command--reducing a Crit-1 function to a single
electronics string (AW&ST Nov. 4, 2002, p. 43).
Had the back-up cable failed at booster ignition,
the aft sections of both boosters would have ripped
off and the T-zero umbilicals would have stayed in the
orbiter, resulting in a catastrophic liftoff accident.
The incident was intensively investigated at the
time. But what the post-Columbia Crit-1 review has
found is that the cable had been
showing anomalous behavior on non-critical
low-voltage functions on more than one occasion,
sources said. Those analyses, however, failed to
adequately address the Crit-1 functions of the higher
voltage portions of the cable--which eventually failed
during a launch. Whether that process was proper is
being re-examined by NASA.
By coincidence, STS-112 was also the same flight
where a large section of external tank bipod foam
separated and struck the aft skirt of the left
booster, but without causing damage. Had managers
stopped flights after STS-112 to fix the bipod foam
problem, the Columbia accident might have been
prevented.
The board last week once again revised the
scorecard on bipod foam separation incidents. The new
data adds an additional sixth bipod separation event
(including Columbia's) and adjusts the total number of
shuttle flights where the condition could not be
verified photographically to 39 of 113 launches. The
board believes that statistically, there were possibly
three unseen bipod separation events.
This means that about nine missions in the program
had the potential for the same impact suspected of
breaching Columbia's wing. The data indicate that,
statistically, there was chance for such bipod
separations about once every 12-13 missions--about 10%
of all shuttle flights.
The board and NASA last week jointly agreed on a
working scenario for the Columbia accident that
centers the breach in the left wing at reinforced
carbon-carbon (RCC) Panels 8-9. But it leaves open for
determination key questions such as whether the
external tank launch debris impact caused the breach,
whether materials deficiencies were involved and
whether the breach itself involved separation or
fracture of a piece of RCC or its adjoining T-seal.
Even this broad working hypothesis will better
focus the complex text and analysis that needs to be
completed, Gehman said.
The Board has not yet cited the foam impact as a
direct factor in the accident because it still does
not have direct physical evidence. "But the board is
certainly suspicious that the foam had something to do
with this," Gehman said.
That
suspicion was again bolstered last week by additional
data on Columbia's OEX
recorder that showed a pressure spike--like that
consistent with a transient shock event--on a pressure
sensor mounted behind RCC
Panel 9 just a moment after launch cameras captured
the debris impact in that area.
"We are very careful that we do not have a
scenario-based investigation," Gehman said. He noted
the Columbia board findings will probe much deeper
than did the presidential commission that investigated
Challenger where the failure of a booster O-ring was
the irrefutable hardware cause. Initial foam impact
tests at the Southwest Research Institute on sections
of belly tile last week created little damage to the
tile. "If we find areas of safety, or risk assessment,
or budgets or oversight or quality control that we
think need to be improved in order to make shuttle
safer to fly, our report will be rich and complete and
cover all these subjects
and not be
dependent upon whether the foam broke the RCC
or not," he said.
To account for the possibility that technical
factors other than the debris hit may be involved and
to capture the decision-process aspects of the
accident, the board will structure its report in four
different levels:
* Direct Cause: If, by foam impact tests or
other means, the board is able to specifically
identify the foam impact or materials or RCC
attachment flaws that caused the accident, these will
be cited as a direct cause.
* Contributing Factors: "Those would be such
things as a weakening of the leading edge. They might
be things such as quality control at the shop floor or
the construction processes in building the bipod ramp
in the first place," Gehman said.
* Root Causes: Gehman said the board is
going to reserve this third category for perhaps
"aging spacecraft" issues or "cultural kinds of
things" like NASA budget impacts, manpower issues, the
management system and the attitude of managers in the
system.
* Significant Observations: This final
category will be reserved for what board members
believe are individual significant items they wish to
highlight.
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