The independent task group
responsible for watching over NASA's efforts to launch the STS-114 mission
aboard Discovery, the first space shuttle to fly since the Columbia
disaster, is standing down, with some of its members criticizing the space agency's return to flight work.
With the release today of its
220-page final report to NASA, the Stafford-Covey Task Group will no longer
oversee the space agency's shuttle safety work, the group's leaders, veteran
astronauts Thomas Stafford and Richard Covey, told reporters during a Wednesday
teleconference. [The final report is available at the task group's website here.]
Some personal
observations by task group members - included as an annex to the final report
for NASA chief Michael Griffin - criticized NASA's return to flight efforts as
disappointing.
"It is difficult to be objective
based on hindsight, but it appears to us that lessons that should have
been learned have not been," a group of seven task group members wrote.
"Perhaps we expected or hoped for too much."
NASA still has one more test flight
- STS-121
aboard Atlantis - before achieving its return to flight goals, but shuttle
officials have pledged
not to launch another orbiter until resolving external tank foam debris shedding
issues that cropped up during liftoff of Discovery's STS-114 mission.
"The agency ought to have, and ought
to be able, to go out and solve these problems themselves without a lot of
external oversight," Covey said, adding that the task group has always been an
advisory body only, not an oversight board.
NASA spent more than two years and
$1.4 billion to return its shuttle fleet safely to flight following the loss of
Columbia and its seven STS-107 astronauts in 2003. The Stafford-Covey Task
Group watched over those efforts, ultimately passing NASA on 12 of the 15
recommendations which the Columbia Accident Investigation Board (CAIB) deemed
should be addressed before Discovery's launch. In all, CAIB members made 29
recommendations for NASA's consideration.
The Columbia orbiter broke apart,
its crew killed, as the shuttle reentered the Earth's atmosphere on Feb. 1,
2003. CAIB investigators later pinned the physical cause of the disaster on a
suitcase-sized chunk of foam that fell from Columbia's external tank at launch
and pierced the heat shield lining its left wing leading edge. The resulting damage
left the orbiter and its crew vulnerable to the searing heat of reentry.
After successfully launching
Discovery and its STS-114 astronaut crew into orbit on July 26, shuttle and
mission managers were disappointed to find that a nearly 1-pound piece of foam
had fallen
from the spacecraft's external tank, though it did not strike the orbiter. The
1-pound piece of foam separated from a protective ramp that shields tank
electrical and plumbing lines from air stresses during launch, and was thought
to be safe by engineers and shuttle managers.
Several other debris chunks were
deemed to large to be safe, NASA officials said. Tank engineers had previously anticipated the
largest debris sources to be about the size of a marshmallow
and weigh about one-tenth
of a pound.
"The hard fact of the matter is that
the external tank will always shed debris, perhaps even pieces large enough to
do critical damage to the orbiter," the task group's final report stated.
Eliminating critical foam debris
during launch was one of the three
recommendations NASA failed to accomplish in the eyes of the task group.
The agency did not fully meet recommendations to harden its orbiter fleet
against damage or develop mature repair methods that could be relied upon to
fix shuttle heat shields in orbit, the task group found.
However, Discovery's crew did test
some basic repair methods during their flight - including two methods
to repair damaged heat-resistant tiles and panels as part of a spacewalk. STS-114
mission specialist Stephen Robinson also performed the first in-flight repair
of a shuttle's heat shield when he removed two filler strips jutting from
between the orbiter's belly-mounted tiles.
Those successes are a key example of
NASA's hard work to increase shuttle flight safety, Covey said.
"You only have to look at how much
we were able to determine on what happened on that flight," Covey said of
Discovery's STS-114 mission. "For the first time ever, the thermal protection
system was basically certified on orbit. It took out a lot of the questions
that we had before the Columbia accident."
Personal opinions
In addition to delivering their final
report, some of the 26 members of the Stafford-Covey Task Group included
personal observations - not official task group findings -of NASA's progress
earmarked for the agency's top administrator Michael Griffin.
"We included them in the report
because the [NASA] administrator asked that they be included...in an annex,"
Covey said, adding that neither he nor Stafford would comment on the opinions.
In one observation, seven task group
members took issue with portions of the space agency's return to flight effort,
citing that - among other aspects - NASA constantly set launch targets a few
months out which prevented engineers from taking full advantage of a two-year
stand down period.
Decisions to develop certain tile
repair methods, the orbiter inspection boom and set flight manifests were
affected due to the unrealistic launch targets, the task members stated.
"From our vantage point, the process
for selecting a launch date was flawed, if indeed there was a process," wrote the
group, which consisted of a former director
of the congressional budget office, a veteran aerospace engineer, a former
shuttle astronaut, former under secretary of the U.S. Navy, two professors and
a nuclear engineer.
While Covey said personal
observations cannot be applied to the task group as a whole, he did add that
NASA may have hindered its own return to flight work by lunging headfirst into
all of the CAIB recommendations, rather than prioritizing the items into a
focused structure.
"The fact that the agency spent two
years to completely meet the recommendations of the CAIB was a challenge to
them, and one that may have affected their return to flight differently if they
had prioritized rather than set a blanket 'We're going to do them all,'" Covey
said.
Last week, NASA officials said
it is unlikely that they will be able to launch Atlantis during September,
though another opportunity will open in November. An update on NASA's foam
debris analysis is expected Monday.
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