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GAO: NASA Recycling Effort Flawed
Another report from Gannett News Service's Eun Kyung Kim:

WASHINGTON - Inconsistent descriptions and wrong information are hampering a $29 million equipment recycling program being used by NASA as it prepares to retire the space shuttle program, according to a federal audit released today.

NASA started the program to help it decide what to do with more than 1.2 million types of equipment resulting from the shuttles' retirement next year.

Auditors from the Government Accountability Office, which reviewed the program at five NASA centers, said the agency lacked "adequate oversight and detailed guidance on what type of information should be included" in identifying equipment. That resulted in widely varying descriptions.

"For example, the same type of computer server equipment was described as a 'disk array,' 'disk drive unit,' and 'storage array unit.' These differences in descriptions may lead to reutilization opportunities being overlooked," the GAO said in its report.

Rep. Bart Gordon (shown at left), chairman of the House Science and Technology Committee, requested the report.

"NASA clearly is on the right track in trying to develop a tool for users to assess whether they needed to purchase new equipment or could avail themselves of existing resources," Gordon said. "But if the system contains unreliable and incomplete descriptions and if subsequent lengthy searches still need to be conducted, then users will lack confidence in the system and avoid using it."

The GAO made five recommendations in its report; NASA agreed with four of them.

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Next-Gen Weather Satellite Arrives at KSC
The latest in a series of unmanned spacecraft preparing to launch from Cape Canaveral has arrived on the Space Coast for final testing.

A next-generation National Oceanic and Atmospheric Administration weather satellite, named GOES-O, arrived Tuesday at Kennedy Space Center in a C-17 cargo plane.

It was trucked to Astrotech in Titusville for processing.

The spacecraft, the second of three advanced Geostationary Operational Environmental Satellites (GOES), is targeted to launch April 28 on a United Launch Alliance Delta IV rocket.

When activated in orbit more than 22,000 miles above Earth, the Boeing Co.-built satellite will observe 60 percent of the planet, an area including the United States.

Better imaging systems will improve the forecasting and tracking of severe weather events and provide data for climate studies.

GOES-O - to be renamed GOES-14 on orbit - follows GOES-13, which launched from Cape Canaveral on May 24, 2006. The third satellite, GOES-P, is tentatively scheduled to be the Cape's last launch this year - on New Year's Eve.

GOES-14 will join GOES-13 as on-orbit back-ups for satellites that are nearing the end of their lives.

Here's a fact sheet providing more information about GOES-O.

Last month, NASA's Lunar Reconnaissance Orbiter (LRO) and the Lunar CRater Observation and Sensing Satellite (LCROSS) were shipped to KSC and Astrotech. Their launch has been pushed back from April 24 to May 20.

NASA's Kepler telescope now sits atop a United Launch Alliance Delta II rocket ready for launch at 10:49 p.m. Friday. It was delivered from Astrotech to Launch Complex 17-B on Feb. 19.

An Air Force communications satellite is also near mating with a ULA Atlas V rocket tentatively scheduled to launch March 14.

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It's Space Day in Tallahassee
Bill Cotterell of Gannett's Florida Capital Bureau offers this report:

TALLAHASSEE - Scores of aerospace executives and a pair of astronauts are working the Florida Capitol today to promote awareness of how important space exploration is to the state's economic health and scientific future.

This year's Space Day is clouded by economic uncertainties, with the Space Shuttle program slated to end next year and the state facing extremely hard financial times.

Thousands of Brevard-based engineers and missile technicians could be looking for new jobs soon, and the Missile Defense Agency in Alabama is likely to pick up many of them.

Astronauts Al Worden and Peggy Whitson joined the 80 company executives and local officials celebrating Space Day at the Legislature.

The event's 22 sponsors ranged from Boeing and Lockheed Martin to Space Florida, the state public-private consortium that promotes commercial exploration opportunities.

"It's a difficult row to hoe," said Sen. Mike Haridopolos, R-Merritt Island. "We know the vital nature of it, not only from NASA but also commercial space. We want to make sure people understand the importance of Florida being the worldwide address for space."

The annual observance began Tuesday with the showing of an IMAX film, "Space Station," at the Challenger Center in the Capitol's shadow. On Wednesday, participants worked hallways of the House and Senate office buildings to meet with lawmakers about education and economic-development activities relating to space.

The group also set up an information display on the Capitol's second floor, with a space suit-clad volunteer posing for pictures with state officials and tourists and the real astronauts signing autographs.

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NASA Targets March 11 For Discovery Launch
NASA is pressing ahead with plans to launch shuttle Discovery next week and is moving its target launch date up a day to Wednesday. The date is expected to be firmed up at a flight readiness review on Friday.

The decision followed an all-day review of extensive testing and engineering analyses prompted by the failure of a critical main propulsion system valve during Endeavour's successful launch last November.

Managers "feel confident enough that they can press ahead with a Flight Readiness Review based upon all of the testing and analysis," said Kennedy Space Center spokesman Allard Beutel.

At the end of the meeting, NASA shuttle program manager John Shannon polled all members of a board responsible for making key program decisions, one that includes independent safety offices.

"It was a unanimous decision by all parties to press ahead," added Kyle Herring, a spokesman at NASA's Johnson Space Center in Houston.

Liftoff time on Wednesday would be 9:20 p.m.

NASA must launch Discovery by March 13 to complete its planned 10-day stay at the International Space Station and then depart before the March 26 launch from Kazakhstan of an already planned station crew rotation mission. Otherwise, the shuttle launch would have to be postponed until around April 7.

Seven astronauts aim to fly Discovery on a mission to haul up a fourth and final set of American solar wings to the International Space Station.

Discovery mission commander Lee Archambault and his crew will go into quarantine tonight at Johnson Space Center in Houston to protect the option to fly on March 11. The crew includes pilot Tony Antonelli and mission specialists Joseph Acaba, Steve Swanson, Richard Arnold and Koichi Wakata of the Japanese Aerospace Exploration Agency.

Wakata will repplace current station engineer Sandra Magnus, who will return to Earth on Discovery. He will be the first Japanese astronauts to serve a long-duration tour on the outpost.

The crew will arrive at Kennedy Space Center about 3 p.m. Sunday. A three-day launch countdown will begin about 7:30 p.m. that night.

One of three gaseous hydrogen flow control valves failed during Endeavour's successful launch last November.

About the size and shape of pop-up lawn sprinklers, the poppet valves regulate the flow of gaseous hydrogen into the shuttle's external tank during the nine-minute flight into orbit. The gaseous hydrogen keeps pressures within the tank at proper levels as propellant within it is exhausted by the ship's three main engines.

Too little pressure could cause an engine shutdown in flight. Too much pressure in the tank could force open a separate relief valve that would dump combustible gaseous hydrogen overboard - a potentially explosive fire hazard.

Post-flight inspections on the failed Endeavour valve showed a piece of its lip cracked off. Engineers had feared debris could rupture gaseous hydrogen pressurization lines that run between the shuttle's main engines and the external tank.

Of particular concern are 90-degree bends in the lines about five inches from the engines. High-velocity impact tests have shown that debris could puncture the lines in that area in a worst-case scenario.

Some engineers thought the area should be reinforced as a result, but managers decided that work would not be required to press ahead with Discovery's launch. Tests have shown three valves installed on Discovery earlier this week have no discernable flaws, so no debris large enough to cause critical damage could be created, the analyses show.

"We've installed the best crack-free poppets -- at least to the limit of detection capability that we have," Herring said.

NASA also has been running tests designed to determine the effectiveness of inspection techniques the agency uses to detect microscopic cracks in the valves.

The agency traditionally has used electron microscopy and dye penetration tests to detect cracks. But extensive analyses of valves in inventory have shown that cracks have gone undetected after those tests.

NASA in the last several weeks has been using a non-destructive technique known as an eddy current test to detect cracks. The process uses electromagnetic induction to detect subtle changes in current that are indicative of cracks. Cracks as small as 1/20,000th-of-an-inch can be detected.

A growing confidence in the effectiveness of eddy current testing led to the decision to press ahead with a formal, executive-level flight readiness review on Friday. The flight rationale that will be presented will note that any cracks on the valves on Discovery would be so small that they could not possibly liberate any debris that would puncture a pressurization line.

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NASA dealing with bogus spacecraft parts
Gannett News Service's Eun Kyung Kim reports from Washington:

NASA officials are dealing with a growing problem of unknowingly buying falsely certified or outright bogus spacecraft parts, the agency's chief said today.

"We find out about it while sitting atop a rocket, or worse, find out about it in space," NASA's acting administrator, Christopher Scolese, told members of the House Science and Technology Subcommittee on Space and Aeronautics.

Scolese said after the subcommittee hearing that the issue is "becoming a bigger problem for us." He cited the Kepler, an unmanned probe that will launch tomorrow from the Cape Canaveral Air Force Station.

NASA learned in December that a supplier had falsely certified that titanium for defense aircraft and space vehicles -- including the Kepler -- met government standards, said J.D. Harrington, a NASA spokesman. NASA investigated and determined the titanium did meet its requirements, he said.

"The piece we were specifically concerned with was Kepler's spider hub assembly," Harrington said. "If defective, the mission would be a total loss. After several weeks of material analysis, we found the titanium to be well within the required performance parameters needed for mission success."

Harrington said officials also reviewed the titanium used in the Delta II rocket that will carry the Kepler.

"It, too, received a clean bill of health. This is a closed issue for us," he said.

Scolese said the increasing number of fraudulently tested parts is a problem for the entire aerospace industry. Last November, NASA's Office of Safety and Mission Assurance issued a policy directive to deal with counterfeit parts and potential sources of fraud, along with other issues.

"If it affects the industry, it affects the agency ....(and) all of our missions," Scolese said.

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Live at the Cape: Delta Darts Through Night Sky
A Delta II rocket is hauling a robotic NASA planet-hunter toward orbit tonight after a dazzling nighttime liftoff from Cape Canaveral Air Force Station.

The 12-story United Launch Alliance rocket and its payload -- NASA's Kepler spacecraft -- blasted off from Launch Complex 17-B at Cape Canaveral Air Force Station at 10:49 p.m. The ontime liftoff followed a flawless countdown.

The Delta II looked like a ball of white-hot fire as it rose into the night sky. A minute into flight, six of its nine solid rocket motors were jettisoned and could be seen dropping back toward the Atlantic Ocean like sparling red-orange embers.

Its three air-lit boosters ignited and burned without problem.

The first stage main engine cut off on time, and the second stage ignited and is propelling the Kepler spacecraft toward orbit.

The third stage of the Delta II is scheduled to deploy the spacecraft about 11:51 p.m. Check back to see if NASA can declare mission success.

kl90

Live at the Cape: Kepler Launch a Success
NASA's Kepler spacecraft separated from the Delta II rocket's third stage just over an hour after blasting off from Cape Canaveral Air Force Station, marking a successful conclusion to Friday night's launch.

Mission managers received more good news after midnight.

Kepler communicated with a tracking station in California at 12:11 a.m. EST Saturday, and a short time later confirmed that its solar panels were producing power.

All systems appear to be operating properly as the spacecraft coasts toward an orbit trailing Earth around the sun.

It took several minutes to confirm separation from the United Launch Alliance vehicle through a tracking station in Australia, adding some suspense to the outcome.

Launch managers said they were trying to figure out what caused the delay, but the desired result was achieved.

"It was a very smooth countdown," said Omar Baez, launch director for NASA's Launch Services Program, which is based at Kennedy Space Center.

The program rebounded from a setback last month, when a NASA climate satellite failed to reach orbit after launching from California.

Friday marked the 139th successful launch by a Delta II in the program's 20-year history.

Kepler now begins a 60-day commissioning phase before it officially begins hunting for planets.

Once it is up and running, around May, Kepler will begin to stare at more than 100,000 stars in the Milky Way, recording minute changes in light caused by crossing, or transiting, planets.

For at least 3.5 years, the $600 million mission will monitor changes in the stars' brightness.

Kepler hopes to determine if rocky planets the size of Earth are common or not, and to estimate how many orbit in habitable zones around their stars - places where liquid water and life could exist.

It takes about a year for Earth-size planets to circle the habitable zone of stars like our sun, and scientists want to see three transits before confirming a planet's existence.

So mission findings that are expected to rewrite textbooks will likely take about four years to announce.

Mission scientists expect to find dozens of Earths in habitable regions, but say the results will be just as profound if they find none.

"Kepler is, frankly, a mission for the ages," said Geoff Marsy, a science co-investigator for the mission from the University of California at Berkeley, before the launch. "It is the first telescope capable of detecting Earth-like planets around other stars. And of course since the time of the Greeks - Aristotle, Democritus - they pondered whether the Earth was unique."

Ground-based telescopes have found more than 300 planets over the last 15 years, mostly gas giants that could not support life.

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Crew at KSC: "Ready to Get Going"
Space shuttle Discovery's crew today flew into Kennedy Space Center in preparation for Wednesday's launch to the International Space Station on a two-week construction mission.

The seven astronauts arrived from Houston by 3 p.m., touching down on the shuttle's three-mile landing strip after steering five T-38 training jets up the coast for a view of Discovery resting on Launch Pad 39A.

In brief remarks, mission commander Lee Archambault thanked NASA workers around the country who spent more than a month studying a problem with valves in the shuttle's main propulsion system.

Shuttle managers concluded by last week that Discovery was safe to fly. The problem delayed the STS-119 mission from its original Feb. 12 launch date to a planned 9:20 p.m. liftoff on Wednesday.

"We've very happy it's been resolved successfully," Archambault said. "We're ready to get going."

Archambault was flanked by pilot Tony Antonelli and mission specialists Joe Acaba, Ricky Arnold, John Phillips, Steve Swanson and Koichi Wakata, all wearing blue flight suits.

Around 6 p.m., Archambault and Antonelli were scheduled to practice landings in a modified Gulfstram jet that mimics an orbiter's handling on descent.

The rest of the crew will participate in briefings at their quarters at KSC's Operations and Checkout Building.

About a dozen representatives from the Japan Aerospace Exploration Agency (JAXA) and Japanese media organizations were on hand for Wakata's arrival. At left, JAXA's Yushiya Fukuda made the event's best fashion statement, with an orange T-shirt and light blue jacket that featured images of a smiling Wakata.

Wakata is set to become the first Japanese astronaut to conduct a long-duration spaceflight when he replaces NASA astronaut Sandy Magnus as a space station flight engineer.

"I'm excited to stay on board the station for a little while," Wakata said today, who is scheduled to return to Earth with the STS-127 shuttle crew expected to fly in mid-June.

Discovery's three-day countdown to launch is scheduled to begin at 7 p.m.

After reaching the space station about two days into the flight, the crew plans to install the last segment of the space station's football field-length central truss.

The truss, called S6, will be installed on the station's starboard side. It holds the last pair of massive power-generating solar wings, which are needed to boost the station's capacity to support science experiments and larger crews.

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Crew Arrives, Countdown Begins
Mon, 09 Mar 2009 07:18:09 AM GMT+0800

Space shuttle Discovery’s seven astronauts arrived at Kennedy's Shuttle Landing Facility in their T-38 aircraft Sunday at about 2:45 p.m. EDT in preparation of Wednesday’s launch. The official countdown clock for STS-119 began counting down from the T-43 hour mark at 7 p.m Sunday evening leading to a planned launch at 9:20 p.m. on March 11.

kl90

STS-119 Astronauts Arrive for Launch

Commander Lee Archambault will lead Discovery's crew of seven, along with Pilot Tony Antonelli, and Mission Specialists Joseph Acaba, John Phillips, Steve Swanson, Richard Arnold and Japan Aerospace Exploration Agency astronaut Koichi Wakata on mission STS-119 to the International Space Station.

The Discovery crew members are set to fly the S6 truss segment and install the final set of power-generating solar arrays to the International Space Station. The S6 truss will complete the backbone of the station and provide one-fourth of the total power needed to support a crew of six.

kl90

NASA cooperating with Congressional probe
Eun Kim reports from our Washington bureau ...

NASA said it will cooperate with a congressional probe into charges that a University of Florida professor funneled millions of NASA grant dollars into the personal bank accounts of his family members.

The chairman of the Senate Commerce, Science and Transportation Committee, which has oversight of NASA policy, requested the investigation after reports surfaced last week about the alleged scam.

Federal agents recently raided the university office of Samim Anghaie, who, along with his wife and two grown sons, set up a company called New Era Technology, or NETECH. The company along with another set up by Anghaie are recipients of NASA grants.

Sen. Jay Rockefeller, in a letter to NASA Acting Administrator Christoper Scolese, asked the agency to turn over all grants, contracts and other awards it made to NETECH, Anghaie or his family members. The agency has until March 29, according to the letter, which was released today.

kl90

Discovery on track for launch
The forecast remains excellent for Wednesday's planned 9:20 p.m. launch of space shuttle Discovery, and NASA is not working any serious technical issues, officials said in a briefing this morning at Kennedy Space Center.

"At this point, we have no real concerns," said Steve Payne, NASA test director. "Our systems are in good shape. The countdown is proceeding on schedule like it should be, and we are ready for the exciting mission that lies ahead of us on Wednesday night.

There is only a 10 percent chance of local weather that would spoil a liftoff, said Air Force meteorologist Kathy Winters. The forecast also looks good at U.S. and international sites where the shuttle could attempt landings during an aborted launch.

Engineers were troubleshooting what Payne called a minor issue involving an electrical connection during tests of valves prior to loading of the shuttle's external tank.

The issue is not related to the hydrogen gas flow control valves that delayed Discovery's launch for a month, and Payne said they it would not interfere with Wednesday's scheduled launch.

"We have a contingency plan even if we, for some reason, couldn't get it fixed," he said. "It's something that that we use post-launch and we have a work-around for it."

Discovery is to set sail on a 14-day mission to the International Space Station.

A crew of seven astronauts led by mission commander Lee Archambault will attempt to install the last piece of a the station's 11-segment central truss.

The $298-million, 45-foot-long girder includes a final pair of American solar array wings, which will span 240 feet from end to end once they are deployed.

If the mission stays on schedule, the shuttle would return to KSC at 3:27 p.m. March 25.

Today, Archambault and pilot Tony Antonelli were expected to continue practicing landings in the Shuttle Training Aircraft, and Payne said the crew was "in very good spirits and really eager to get flying."

Shuttle processing milestones today include:

- Preparations for the loading of super-cold liquid hydrogen and liquid oxygen into the shuttle's 15-story external tank. Loading is scheduled to start at 11:55 a.m. Wednesday.
- Crew equipment stowage.
- A built-in hold at 3 p.m. at the T minus 11-hour mark.
- Checks of the ground communications network and orbiter communications system.

The Rotating Service Structure wrapped around Discovery at Launch Pad 39A is scheduled to be retracted at 1 a.m.

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An American astronaut and a Russian cosmonaut will venture outside the International Space Station today to set up a European experiment and conduct an extensive photographic survey of the exterior of the Russian side of the outpost.

Station skipper Mike Fincke and flight engineer Yury Lonchakov are slated to head outside the Russian Pirs airlock at noon for an excursion that is expected to last five-and-a-half to six hours.

Fincke and Lonchakov aim to install an experiment they were unable to activate during a spacewalk in December. The experiment since has been fixed and the two spacewalkers are going to make a second attempt to get it running. The experiment is a suitcase-sized container that is filled with samples of biological and organic samples that will be exposed to the space environment for several months.

The spacewalkers also will photograph the exterior of the Russian Zvezda Service Module, the Zarya module, the Pirs airlock and the rest of the Russian side of the station to document micrometeorite and space debris hits and see generally how the hardware has fared during up to a decade in orbit.

Fincke will be wearing a Russian Orlan spacesuit with red stripes. Lonchakov will be wearing an Orlan suit with blue stripes. It will the second career spacewalk for Lonchakov and the sixth for Fincke.

kl90

SPACE SHUTTLE DISCOVERY (STS-119)
Space shuttle Discovery's STS-119 flight will deliver the International Space Station's
fourth and final set of solar array wings, completing the station's truss, or backbone.
The arrays will provide the electricity to fully power science experiments and support
the station's expanded crew of six in May. The 14-day flight will feature four spacewalks
to help install the S6 truss segment to the starboard, or right, side of the station
and the deployment of its solar arrays. The shuttle also will deliver the first Japan Aerospace
Exploration Agency’s resident station crew member and bring back a U.S. astronaut
after more than three months aboard the orbiting laboratory.


Lee Archambault (ARSH-um-boe)
Commander (Colonel, U.S. Air Force)
● Veteran of one spaceflight, pilot on STS-117
● Age: 48, Hometown: Bellwood, Ill.
● Married with three children
● Logged 4,250+ hours in 30+ different aircraft
● Enjoys bicycling, weightlifting and ice hockey


Tony Antonelli (an-tuh-NEL-lee)
Pilot (Commander, U.S. Navy)
● First spaceflight
● Age: 41, Born: Detroit
● Married with two children
● Logged 3,200+ hours in 41 different aircraft
● Interests include snow boarding and NASCAR


Joseph Acaba (ah-CAH-bah)
Mission Specialist-1
● First spaceflight
● Former middle and high school science teacher
● Age: 41, Hometown: Anaheim, Calif.
● Served two years in U.S. Peace Corps
● Enjoys camping, kayaking and scuba diving


Steve Swanson
Mission Specialist-2
● Veteran of one spaceflight, STS-117
● Accumulated over 13 hours in two spacewalks
● Age: 48, Hometown: Steamboat Springs, Colo.
● Ph.D. computer science, Texas A&M, 1998
● Married with three children


Richard Arnold
Mission Specialist-3
● First spaceflight
● Former middle and high school science teacher
● Age: 45, Hometown: Bowie, Md.
● Married with two daughters
● Enjoys guitar, running, camping


John Phillips
Mission Specialist-4
● Veteran of two flights and one spacewalk
● Expedition 11 flight engineer
● Age: 57, Hometown: Scottsdale, Ariz.
● Ph.D. geophysics & space physics 1987, UCLA
● Married with two children


Koichi Wakata (ko-EE-chee) (wah-KAH-tah)
Mission Specialist-5/Expedition 18 Flight engineer
● Veteran of two spaceflights, STS-72 & STS-92
● Age: 45, Born: Saitama, Japan
● Ph.D. aerospace engineering, Kyushu-U, 2004
● Married with son
● Returns on STS-127, targeted May 2009


Sandra Magnus
Expedition 18 Flight Engineer & Science Officer
Mission Specialist-5
● Flew on STS-112 & 126 in November to station
● Ph.D. material science & engineering, GIT 1996
● Age: 44, Born: Belleville, Ill.
● Returns to Earth on STS-119

[ 本帖最后由 kl90 于 11-3-2009 12:55 AM 编辑 ]

kl90

Smile, Zvezda
Astronaut Mike Fincke and cosmonaut Yury Lonchakov have nearly completed a photographic survey of the International Space Station's Zvezda service module, the second major goal of a spacewalk that is running well ahead of schedule today.

The two spacewalkers stepped out of the Pirs docking compartment's airlock at 12:22 p.m. EST.

After accomplishing several tasks, including installation of a European materials experiment, they took hundreds of pictures of 28 targets to document the service module's condition after nearly nine years in space.

Targets included thrusters, radiator panels, insulation, hand rails, docking mechanisms and navigational antennas, including one that helps dock approaching Russian spacecraft.

Lonchakov had to manually dock a Progress cargo vehicle last fall after the automated system failed.

The pictures are part of a project called "Panorama" to give Russian flight controllers an updated picture of the Zvezda module's condition, including whether it has suffered any damage from micrometeorite debris or needs any immediate maintenance.

Fincke and Lonchakov are expected to head back inside after finishing their camera work.

Russian mission controllers feathered a set of solar arrays attached to the service module to ensure a clear path back to the hatch.

They believe Fincke - visible in the pictures in the spacesuit with red stripes - might have inadvertently touched one early in the spacewalk, but if so, it caused no harm to Fincke or the array.

The spacewalk, which was expected to last five hours and 45 minutes, is said to be running over an hour ahead of schedule.

kl90

ISS Spacewalk Complete
Astronaut Mike Fincke and cosmonaut Yury Lonchakov have returned safely inside an International Space Station airlock and closed the hatch, ending a nearly five-hour spacewalk.

The Expedition 18 duo, assisted by Sandra Magnus from inside the station, completed all their scheduled tasks.

Chief among those were the installation of a European biological materials science experiment outside the Zvezda service module, and photographing the module to assess its condition after nearly nine years in orbit.

Other jobs included trimming a set of six straps positioned near the Pirs docking compartment, to ensure that they don't interfere with incoming Russian vehicles as they dock.

They also rotated a container holding another materials science experiment.

The spacewalk was the second by Fincke and Lonchakov as a team, and the second ever for Lonchakov, totaling 10 hours and 27 minutes.

It was the sixth for Fincke, who now has 26 hours and 12 minutes of spacewalking time, all in Russuian spacesuits.

Overall, it was 120th spacewalk in support of station assembly and maintenance since construction began in 1998, totaling 755 hours and 56 minutes.

The spacewalk was an attempt to get ahead of some work before space shuttle Discovery's expected arrival on Friday - assuming it launches on schedule at 9:20 p.m. Wednesday.

The shuttle is approaching a "cutout" in advance of the March 26 launch of a Soyuz spacecraft.

If technical or weather delays Wednesday's shuttle launch several days, the mission could be shortened and the number of spacewalks reduced (four are planned) to make sure the mission is finished before the Soyuz arrives on station.

"If we have to shorten the mission, then by getting this (spacewalk) out of the way, it would give us more flexibility for accommodating any planned work that we didn't get done by having to shorten the mission," said Robbie Ashley, the payload manager for the STS-119 mission.

That work could then be done after Discovery completes its 10-day stay at the station and returns home.

However, the weather forecast for Wednesday is excellent, and mission managers today reported no serious technical issues that threaten the launch.

kl90

Tank-related leak postpones shuttle launch
Editor's Note: New details, briefing times, etc. added at 4:19 p.m.

Tonight's space shuttle launch is postponed because of a leak of hydrogen gas during the fueling this afternoon.

NASA launch crews and managers are scrambling to identify repair options and the earliest they could try to launch is tomorrow night. Liftoff would be 8:54 p.m. Managers are to convene at 5 p.m. and NASA plans a news briefing to explain its options no earlier than 7 p.m. We'll carry it here live.

However, engineers are still gathering data and it's unclear whether the problem could be repaired in time to try again tomorrow or even later this week.

NASA must launch by Monday or wait until April 7. The reason: a Russian Soyuz mission to swap out the crew of the International Space Station. A shuttle orbiter and two Soyuz craft cannot be docked at the outpost at the same time. The crew swap mission must fly on time because of the limited service life of the Soyuz already docked at the station, which serves as the current crew's escape craft. Among other considerations complicating the rescheduling is the planned launch Saturday of an Atlas V rocket carrying a military communications satellite, which may or may not take precedence over the space shuttle mission.

The shuttle fuel loading operation at KSC began at 11:56 a.m., and everything appeared on track with no technical problems and near-perfect weather.

Then, the launch had to be called off about 20 minutes before the tank was full. NASA spokesmen characterized the leak as "slight" and immediately looked into repair options.

The suspect location is in a pipe that routes gaseous hydrogen out of the liquid hydrogen portion of the external tank, helping to keep pressure inside the tank at proper levels. The excess hydrogen is vented through a line to a flare stack at the launch complex that is designed to burn it off.

The leak was detected near a plate that basically serves as a connecting point between pipes from ground equipment on the pad and the external tank. See the photos at right, which show closeups of the connection point about two-thirds of the way up the 15-story fuel tank.

NASA says the leak is not related to one of the gaseous hydrogen flow control valves that prompted a previous one month delay in Discovery's launch.

The astronauts were just over a couple hours from suiting up for flight and heading out to the pad when the launch was called off.

"I imagine they are not too happy about not launching tonight, but they have to have a safe shuttle to fly on so they understand," said Allard Beutel, KSC spokesman.

kl90

NASA plans to repair a leaking hydrogen valve at the launch pad and tryagain Sunday to send up space shuttle Discovery and seven astronauts.

The delay is forcing NASA to shorten the mission and eliminate some planned spacewalks.

If Discovery launches Sunday, at 7:43 p.m., the mission would last 11 days and include three spacewalks instead of four.If the launch comes Monday or Tuesday, which is the last possible day,the flight would last 10 days and feature only one or two spacewalks.

Some work would be passed off to the permanent station crew to do later.

"We'rereally trying hard to make the 15th if we can. The 16th might just bethe day that's out there. The date will be what it is and we'll adjustto it," shuttle launch integration manager Mike Moses said.

AfterTuesday, the shuttle launch must wait until after an already-plannedRussian Soyuz mission to deliver a fresh crew to the space station.

Ashuttle orbiter can't be docked at the ISS while a second Soyuz isthere for a variety of reasons, including the structural strain on thespace station and the inability of life support systems to support 13astronauts and cosmonauts for an extended period of time.

That would mean waiting until April 7. NASA says it can still completeits station construction objectives during a shortened shuttle mission.The space station program prefers the earlier, shorter flight because adelay to April could postpone plans to double the stationâ

[ 本帖最后由 kl90 于 12-3-2009 10:09 PM 编辑 ]

kl90

Teams wait for access to leak location
Teams at the Kennedy Space Center are waiting this morning for the last remnants of liquid hydrogen propellant to evaporate from the shuttle external tank so they can get an up close look at the problem that caused Wednesday's launch scrub.

The area remains dangerous as long as there is fuel in the tank and officials expect to be able to start detailed inspection and troubleshooting work by this afternoon.

What they find will be key to whether or not NASA can try to launch Discovery and seven astronauts on Sunday or on Monday. As of right now, the plan is for NASA managers to meet late today to go over initial findings at the pad.

We'll update as we learn new information. A decision on launching Sunday probably won't be made until Friday.