No quick fix in space
A space walk veteran will attempt a long, difficult repair today.
By CURTIS KRUEGER, Times Staff Writer
Published November 3, 2007
Astronaut Scott Parazynski, 46, takes part in a space walk Sunday. He is on the fifth space shuttle mission and had spent 20 hours on space walks before this mission began.
Dangling 250 miles above Earth, perched on the end of a robotic arm, astronaut Scott Parazynski will reach out this morning and try to repair solar panels that produce electricity for the international space station.
And hope he doesn't get zapped.
This will be a dramatic moment on the space station, an ungainly orbiting laboratory that ranks among the most complex things humans have ever built -- even though it is largely ignored on this planet.
"It's a challenging space walk, but we have them prepared," said NASA spokesman Bill Jeffs in Houston.
Parazynski, one of NASA's most experienced spacewalkers, will try to fix the power supply to the space station.
And it won't be easy. He will use tools that have been triple-wrapped in special tape so they won't conduct electricity and tethered to him so they won't drift off in the void. As Parazynski works, he and the station will zoom through space at more than 17,000 mph, circling Earth as many as four times, long enough for eight sunrises and sunsets.
A double-whammy of bad news created the need for this space walk.
Space shuttle astronauts blasted off from Florida on Oct. 23, and docked at the space station two days later. Then they found problems in 115-foot solar "wings" on each side of the station.
A schedule to keep
These long sets of solar panels produce electricity for the station. In spite of the recent troubles, there's no immediate danger of a power blackout. But NASA next month hopes to fly up a new European-built space laboratory called Columbus, and attach it to the station. Next year NASA plans to fly up Kibo, a Japanese lab.
Both labs will suck a lot more power out of the system, and that's why NASA hopes to fix one of the solar wings today, Jeffs said. If Parazynski can fix one of the contraptions, it will make the space agencies of the United States, Europe and Japan quite happy, because station construction will stay on schedule.
An astronaut earlier this week peered inside a joint that rotates one of these sets of solar panels, so they point toward the sun and create more electricity. He saw something bad: metal shavings. That means something's not working right, possibly metal scraping against metal. This was the first problem. Station managers stopped rotating the panels to prevent any further damage. This slightly reduces power.
Next, astronauts started to unfurl another set of solar panels, which had previously worked properly on another part of the station. But they noticed tears in the delicate, shimmering gold-colored panels, possibly caused by a snag with a long, thin "guide wire" that normally helps hold the panels in place. This was the second problem. So they stopped unfurling, to prevent more damage. The problem is, the panels also might rip more if nothing is done.
Starting about 6:30 a.m. today, Parazynski will strap his feet onto an extension of the space station's robotic arm, and take a 45-minute ride as the arm carries him out to the damaged panels. Then he will install wire devices nicknamed "cuff links" in an effort to prevent more tearing. He may also cut one of the "guide wires" to prevent any more snagging.
Parazynski, 46, a physician and mountaineer, is on his fifth space shuttle mission, and has spent 20 hours on space walks before this mission began.
"I cannot overstate the significance of his experience and his approach to the job," said Derek Hassman, lead flight director for the space station.
First-time astronaut Douglas Wheelock, an Army colonel and test pilot, also will be spacewalking, staying near the base of the solar wing to assist.
If Parazynski can fix the solar wing today, astronauts hope to unfurl it fully so it produces maximum power again, or close too it.
Although more than 100 volts of electricity course through the panels, NASA managers said it's very unlikely Parazynski will be shocked.
A shock would happen only if a metal portion of his space suit touches a damaged portion of the solar wing containing a charged wire, and the crew has taken precautions to prevent that. Astronauts have taped over metal items on the middle of Parazynski's space suit
The space shuttle crew intends to fly back to Earth on Monday, but three astronauts will remain on the station.
The space station is a cooperative construction project among about 15 nations, with the United States and Russia taking lead roles. Humans have been on board continuously since 2000.
Building the station is a horrendously complex job, where nothing is easy. Imagine living in a house where you can't go outside unless you're in a space suit. And if the power, computers, heating or cooling ever go out, it could kill you.
"Living on the space station is very much, probably, like being on a nuclear submarine down on the floor under the Arctic Ocean and saying, 'Is everything working guys?'" said John Olivero, chairman of the physical sciences department at Embry-Riddle Aeronautical University in Daytona Beach.
Considering that seven American astronauts died on a return trip from the space station aboard the space shuttle Columbia in 2003, some question whether the station is worth the risk. Not to mention the cost of more than $100-billion.
Some scientists say many experiments on board the station could be just as easily be performed on unmanned orbiting laboratories -- a lot more cheaply and safely.
Olivero, who has had science experiments aboard space shuttles, sees the value of the missions. One reason the station is valuable, he believes, is that it shows how humans cope with such problems as the loss of bone density and muscle density in long-duration space flights. That information will be essential if humans return to the moon and eventually go on to Mars - both plans endorsed by NASA and President Bush.
Without a space station, "there's virtually no other way that you're going to be able to conduct microgravity research using human beings," Olivero said.
Times staff writer Curtis Krueger can be reached at firstname.lastname@example.org or 727 893-8232.
See it for yourself
For information on how to see the space station overhead, go to: http://spaceflight.nasa.gov/realdata/sightings/cities/region.cgi?country=United_States®ion=Florida
[Last modified November 2, 2007, 23:35:35]
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