In 1970,
the solution involved duct tape, a flight manual's cover, a plastic bag and a
sock.
Three years
later, it was a nylon and mylar umbrella that was assembled with a sewing
machine. In 1985, although unsuccessful, the answer was two makeshift
flyswatters.
And on
Saturday, should NASA proceed as planned, the success of its current mission will
rely on six cuff links.
But it's
not like the 10 astronauts in space can rent the fasteners from the local
tuxedo shop. To save the space station on which they all currently inhabit,
they needed to assemble
their repair tools from the spare parts launched for just such an
occasion.
A rip in
an array
Earlier
this week, after successfully repositioning a truss and solar array assembly to
its permanent berth on the International Space Station (ISS), the crew of shuttle Discovery
and the outpost's own residents set about deploying the segments' pair of
power-generating wings. The first array extended without issue, but as the
second was almost at its full length, the station's commander halted the deploy
after observing
a tear that was forming mid-way along its 110-foot (33 meter) length.
The damage,
which upon closer inspection was found to be two tears -- a 2.5-foot (0.7-meter)
rip and another about one-third the size -- was a serious concern. The ISS was
already at a power handicap as a faulty joint was preventing one set of its
arrays from rotating to track the Sun. Now, with the second set of arrays
unable to extend completely, it too would be unable to follow the
power-providing rays of our nearest star. Although there was enough electricity
to support its current configuration, without repair, the torn wing was
threatening future expansion, including the long awaited launch of European and
Japanese science labs.
Flights
controllers quickly went to work around the clock to develop a daring plan:
using a 50-foot (15-meter) boom designed to inspect the shuttle for damage and
the station's own 50-foot robotic arm, an astronaut will be positioned at the
site of the tear, where he will attempt to clear a snagged guide wire believed
to be the source of the damage, and then repair the torn hinge by inserting
splints, referred to as cuff links, to stabilize the array such that it can be
fully extended. Were it not enough that the boom has never been used for such a
purpose, or that the astronauts were never trained for such a maneuver, the
array, though torn, will still be running a current such that it poses a low
but real risk of shocking the spacewalker.
MacGyver's
mission
Well before
Discovery launched to space on Oct. 23, STS-120 commander Pam Melroy dubbed one
of her six crewmates as the astronaut version of the resourceful TV character
MacGyver. Speaking of her mission specialist from the European Space Agency,
Melroy recalled telling Paolo Nespoli to take all his tools with him to space.
"I
encouraged him to take one of everything because I am sure he's going to build
something in space with it."
As chance
would have it, Melroy would be partially right. Though Nespoli will support
Scott Parazynski and Doug Wheelock during the spacewalk from his vantage point
inside, it was Discovery's pilot George Zamka along with ISS Expedition 16
commander Peggy Whitson who were called upon on Thursday to exhibit their
inner-MacGyver.
Using
strips of aluminum, a hole punch, a bolt connector and 66 feet (20 meters) of
wire, along with detailed instructions sent by mission control, the duo
assembled half a dozen space station-saving cuff link contraptions. If all
proceeds as planned, Parazynski, suspended at the end of the boom-arm assembly,
will slip the cuff link-like tabs through holes in the array's blanket,
enabling it to support the tension exerted when the solar wing is fully
extended.
Like the
sock/duct tape/plastic bag solution that allowed a square-shaped carbon dioxide
scrubber to fit in a
round hole aboard Apollo 13, the success of the cuff links won't be known
until they are installed, but those who worked to devise the fix are optimistic
that failure is not an option.
"We're
faced with a difficult situation," said experienced spacewalker David
Wolf. "I think we're onto a solution that should work and get us pretty
close to a permanently acceptable situation."
How
exactly does one assemble a space station saving cufflink from spare parts?
Very carefully, as appears to be the case in the seven-part
instructions that were uplinked to the astronauts, complete with illustrations
for key steps.
SPACE.com's
live coverage of
the spacewalk begins Saturday morning at 5:00 a.m. EDT (0900 GMT).
Copyright 2007 collectSPACE.com. All rights reserved.
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