WASHINGTON (AFP) — Two astronauts returned from the void Friday after a spacewalk to test new repair techniques for the space shuttle's heat shield, crucial for a new mission to the orbiting Hubble Space Telescope.
Astronauts Robert Behnken and Mike Foreman, who arrived at the International Space Station (ISS) aboard the shuttle Endeavour last week, spent six hours and 24 minutes outside the ISS working on a to-do list that also included replacing a failed circuit breaker-like unit and other maintenance work, NASA officials said.
In testing the heat-shield repair method, the US National Aeronautics and Space Administration sought to make sure astronauts can fix any potential damage during the Hubble mission on August 28, when the shuttle will be moored too far from the ISS, its only habitable shelter in orbit.
Dana Weigel, lead ISS flight director, called the spacewalk and the repair material tests a "huge success" after it concluded.
"I'm thrilled with what we saw today" after the astronauts practiced mixing and injecting the two epoxy-like compounds onto test heat shield materials with an apparatus resembling a caulk gun.
While the materials had been tested on Earth and in the absence of gravity for short periods, NASA wanted to see how it flowed, swelled and set in the gravity-less vacuum of space.
"Working with a fluid in microgravity is certainly no small feat," Weigel said.
"All the tools and techniques that the ground crew developed were excellent."
Officials said that the technique appeared fully workable, but that they will test the materials fully after they are brought back from space to confirm they can survive the extreme temperatures the shuttle endures on its super-heated return into Earth's atmosphere.
Astronauts have been testing different in-space repair techniques on the shuttle's protective layer since a crack in Columbia's heat shield caused it to explode while re-entering Earth in 2003, killing its seven-member crew.
NASA now uses special cameras to scan the shuttle's thermal tiles during flights to see if they have been damaged by debris during liftoff or by micrometeorites while orbiting the Earth. Columbia's heat shield was hit by debris during takeoff.
Getting a workable repair technique is crucial for the Hubble mission, when the astronauts will not have the option of staying aboard the ISS if something goes wrong with the shuttle.
However, NASA officials pointed out, there will be a second shuttle on backup in case of problems in the Hubble mission.
Before testing the new repair methods Thursday, Behnken and Foreman replaced a remote power control module -- the failed circuit breaker -- on the space station's truss, with vivid images of the home-repair-in-space job shown live on NASA television.
The astronauts, however, were unable to remove a power connector from the truss, NASA said.
Meanwhile, Japan's Aerospace Exploration Agency reported that Japanese astronaut Takao Doi experimented with a boomerang's performance in the absence of gravity and confirmed that it flies back much like on Earth.
Doi "threw a boomerang and saw it come back" in the ISS on Tuesday, an agency spokeswoman said.
Doi was asked to test the boomerang by Yasuhiro Togai, a world boomerang champion.
"I was very surprised and moved to see that it flew the same way it does on Earth," the Mainichi Shimbun daily quoted the 53-year-old astronaut as telling his wife in a chat from space.
Thursday's spacewalk was the fourth of five for the Endeavour mission, a record 16-day trip with the primary tasks of installing the first part of Japan's Kibo laboratory and assembling Canada's Dextre robot.
Future missions will deliver Kibo's two other parts, which will give Japan a foothold in the ISS alongside the United States, Russia and Europe, whose Columbus lab was delivered last month.
The microgravity research aboard the ISS is considered a crucial step toward long human missions on the moon and eventually Mars.
Endeavour's crew will conduct a fifth and final spacewalk Saturday before the shuttle undocks from the ISS Monday for its March 26 return to Earth.
NASA wants to complete construction of the ISS by 2010, when its three-shuttle fleet is scheduled to be retired.
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Saturday, March 22, 2008
S.J. woman's water-saving techniques could help you save money
While most of us save for a rainy day, it's the dry kind that Rhondda Nunes worries about.
During the gutter-swelling rainstorms of January and February, she carefully positioned a 30-gallon garbage bin to catch water pouring off the roof of her central Stockton home.
Now, with barely a cloud in the sky in weeks, her cache of rainwater is still nourishing her wild and verdant gardens.
What's more, pots and pans all over the piano instructor's home collect water from dripping faucets, as well as rinse water from the kitchen sink that can safely be used on some plants.
"My friends think I'm nuts," Nunes said.
Her shrinking water bill suggests she is not.
She may, in fact, be an example for the rest of us. Gov. Arnold Schwarzenegger recently urged water conservation as part of his plan to stretch the state's tight water supplies; the governor's goal of a 20 percent reduction in per capita water use by 2020 is at the very least ambitious, some water providers say.
"I kind of had to take a deep breath and say, 'Wow,' " said Bob Granberg, deputy director of Stockton's Municipal Utilities Department. "That's pretty aggressive. I suppose it could be done. We're going to have to get pretty creative."
The state is just beginning to think of ways to achieve Schwarzenegger's goal. Mark Cowin, deputy director of the state Department of Water Resources, said last week that a detailed plan is expected later this year.
He said officials believe the reduction can be accomplished largely through voluntary strategies. For example, many cities already offer rebates to encourage replacement of water-guzzling appliances with new, higher-efficiency models.
"I wouldn't rule out legislation that would require additional mandates or more regulation," Cowin said. "But we're going to work with local agencies to implement plans that are on the books right now."
Reports show that the average Stockton home uses about 22 percent less water during the summertime today than it did in 1987.
Much of that decline reflects advances in low-flush toilets and landscape irrigation in the 1990s, Granberg said. The region's large number of newer homes has also improved conservation since newer homes tend to be more efficient.
Conservation will only get tougher from here, Granberg said. The city's new water plan calls for a 3.4 percent increase in water conservation over the next five years, less than the gains made in the past 20 years.
One of the problems, experts say, is that water is so cheap that there is little financial incentive to conserve. Nunes, for example, pays $1.40 per 100 cubic feet of water. That's about 750 gallons of water, enough for about 75 showers of five minutes.
At that rate, each shower costs less than 2 cents.
The Pacific Institute, a nonprofit think tank that supports increased water conservation methods, has suggested changing water rates to discourage waste.
"The potential for increasing efficiency is enormous," said Peter Gleick, who heads the Oakland-based institute. "Why should we spend billions to try to find new, expensive sources of supply to fill a leaky bucket? Shouldn't we try to plug the leaks first? That's what efficiency improvements do."
Many cities already have detailed conservation programs and laws on the books to back them up. In Lodi, for example, it's illegal to wash down a sidewalk or driveway.
A bucket must be used when washing a car. Hoses are only for rinsing, and no longer than three minutes at a time.
In Manteca, officials have focused on replacing old toilets that swallow five gallons or more in a single flush. Toilets account for most indoor water use. Finding new ways to conserve gets harder as time goes by, said city associate engineer Keith Conarroe.
Not for Nunes. She has an elaborate system: Water is collected in the first bin - which is covered during dry weather to keep mosquitoes out - and then is transferred to four other bins at the side of the house, where it's stored for future use. Neighbors see her lugging pots of water back and forth, from the storage bins to her fish tank, from her kitchen sink to her backyard blooms.
"You get some biceps out of it," she said. "You're also saving money - that's the most practical concern."
http://www.recordnet.com/
During the gutter-swelling rainstorms of January and February, she carefully positioned a 30-gallon garbage bin to catch water pouring off the roof of her central Stockton home.
Now, with barely a cloud in the sky in weeks, her cache of rainwater is still nourishing her wild and verdant gardens.
What's more, pots and pans all over the piano instructor's home collect water from dripping faucets, as well as rinse water from the kitchen sink that can safely be used on some plants.
"My friends think I'm nuts," Nunes said.
Her shrinking water bill suggests she is not.
She may, in fact, be an example for the rest of us. Gov. Arnold Schwarzenegger recently urged water conservation as part of his plan to stretch the state's tight water supplies; the governor's goal of a 20 percent reduction in per capita water use by 2020 is at the very least ambitious, some water providers say.
"I kind of had to take a deep breath and say, 'Wow,' " said Bob Granberg, deputy director of Stockton's Municipal Utilities Department. "That's pretty aggressive. I suppose it could be done. We're going to have to get pretty creative."
The state is just beginning to think of ways to achieve Schwarzenegger's goal. Mark Cowin, deputy director of the state Department of Water Resources, said last week that a detailed plan is expected later this year.
He said officials believe the reduction can be accomplished largely through voluntary strategies. For example, many cities already offer rebates to encourage replacement of water-guzzling appliances with new, higher-efficiency models.
"I wouldn't rule out legislation that would require additional mandates or more regulation," Cowin said. "But we're going to work with local agencies to implement plans that are on the books right now."
Reports show that the average Stockton home uses about 22 percent less water during the summertime today than it did in 1987.
Much of that decline reflects advances in low-flush toilets and landscape irrigation in the 1990s, Granberg said. The region's large number of newer homes has also improved conservation since newer homes tend to be more efficient.
Conservation will only get tougher from here, Granberg said. The city's new water plan calls for a 3.4 percent increase in water conservation over the next five years, less than the gains made in the past 20 years.
One of the problems, experts say, is that water is so cheap that there is little financial incentive to conserve. Nunes, for example, pays $1.40 per 100 cubic feet of water. That's about 750 gallons of water, enough for about 75 showers of five minutes.
At that rate, each shower costs less than 2 cents.
The Pacific Institute, a nonprofit think tank that supports increased water conservation methods, has suggested changing water rates to discourage waste.
"The potential for increasing efficiency is enormous," said Peter Gleick, who heads the Oakland-based institute. "Why should we spend billions to try to find new, expensive sources of supply to fill a leaky bucket? Shouldn't we try to plug the leaks first? That's what efficiency improvements do."
Many cities already have detailed conservation programs and laws on the books to back them up. In Lodi, for example, it's illegal to wash down a sidewalk or driveway.
A bucket must be used when washing a car. Hoses are only for rinsing, and no longer than three minutes at a time.
In Manteca, officials have focused on replacing old toilets that swallow five gallons or more in a single flush. Toilets account for most indoor water use. Finding new ways to conserve gets harder as time goes by, said city associate engineer Keith Conarroe.
Not for Nunes. She has an elaborate system: Water is collected in the first bin - which is covered during dry weather to keep mosquitoes out - and then is transferred to four other bins at the side of the house, where it's stored for future use. Neighbors see her lugging pots of water back and forth, from the storage bins to her fish tank, from her kitchen sink to her backyard blooms.
"You get some biceps out of it," she said. "You're also saving money - that's the most practical concern."
http://www.recordnet.com/
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