HOUSTON - There's trouble brewing in space,
but NASA officials said today that they are confident astronaut crews aboard
the International Space Station (ISS) will work through the difficulties ahead
with mission control's help.
A worrisome
joint on the space station first complicated space shuttle Discovery's STS-120 mission,
which launched a week ago, but today a torn solar array has added to the
headaches of NASA mission managers.
Although
ISS program manager Mike Suffredini said the problems will be challenging to
tackle, he thinks together they are not as serious as now-fixed computer
failures that plagued space station this year.
"I
have in my mind a path through the wilderness on both of these problems. It will
take time, but I have a path through the wilderness," Suffredini said of
the double trouble. "We'll prioritize the work and decide which is the
right thing to work on first."
Ripped
wing
Suffredini said
engineers and mission managers are still heavily discussing a plan of action,
but thinks repairing the solar wing will become priority number-one in the following
days. He said the 2.5-foot (0.76-meter) rip in the 115-foot (35-meter) wing has
not stopped the array's energy-gathering ability, as it is generating 97
percent of its fully deployed power.
"We're
in a very good configuration in terms of being able to sort this problem
out," Suffredini said of the situation. "It doesn't have to look
good, it just have to give us power. We need it out, and need about as much
power as it provides today."
He noted
that mission managers' concerns regard the solar array's fragile state, which dockings
and undockings of space shuttle and Soyuz spacecraft might aggravate.
"Everything
we do has an effect on every other part of the space station," Suffredini
said, noting that only a fully-deployed array is known to be stable. Because
the array fabric is electrically sensitive and difficult to reach with either
the space shuttle or space station robotic arms, a fix would be extremely
challenging, Suffredini noted.
Astronauts
aboard the orbital laboratory monitored the unfurling process following a
seven-hour spacewalk today. The first pair of solar wings, known as 2B,
deployed without incident from the freshly reattached Port 6 (P6) solar array
truss. One of the 4B solar wings opposite of the 2B pair, however, ripped after
unfurling 80 percent of the way along a mast-like post.
Worrisome
joint
The ripped array
came after spacewalker Dan Tani discovered metallic grit in starboard-side joint
early Sunday morning. The mechanism, called the solar alpha rotary joint
(SARJ), is used to gently orient the space station's solar panels toward the
Sun.
Astronauts
aboard the space station determined the metallic grit was iron-containing,
which Suffredini thinks is coming from steel in the mechanism—a likely sign of
damage.
"The
steel components are the bearings ... and gears," Suffredini said of devices
in the SARJ, a motor-driven gear that looks similar to a Ferris wheel. He said
twelve sliding clamps used to hold the 10-foot (3-meter) diameter wheel into
place, called trundle bearing assemblies (TBAs), are suspect and would like to see
astronauts inspect them during Thursday's 6.5-hour spacewalk.
But Suffredini
said the solar array rip will probably divert attention from such a focused
inspection during the fourth of five STS-120 spacewalks.
"I
don't want to do any more damage to the array than has already been done,"
Suffredini said, and preventing it might mean delaying the launch of space
shuttle Atlantis in early December, known as the STS-122 or 1E assembly mission.
"Right this instant ... I wouldn't want to plan a 1E flight until I know
what's better going on."
NASA
launched Discovery and its crew, commanded by Pamela Melroy, on Oct. 23. Astronauts
delivered a new room to the space station and relocated a massive solar array
truss during the now-extended mission, and expect to land at Kennedy Space Center in Cape Canaveral, Fla. on Nov. 7.
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