STS-133 Pre Launch Discussion ( NET Mid Dec)

[EarthlingX]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

http://www.nasaspaceflight.com : STS-133: Structural defect/cracks found under foam damage on ET-137

November 10th, 2010

by Chris Bergin

While troubleshooting on the Ground Umbilical Carrier Plate (GUCP) saw the flight seal removed on Wednesday, engineers have been removing the cracked foam from Discovery’s damaged Thermal Protection System (TPS) area on the flange between the intertank and LOX tank. Two cracks has been found on the structural stringer, which is undergoing an immediate investigation.

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[EarthlingX]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

SDC : New Cracks Found on Shuttle Discovery's External Fuel Tank

By Denise Chow
SPACE.com Staff Writer
posted: 10 November 2010
04:12 pm ET

This story has been updated at 4:56 p.m. EST.

Two cracks have been discovered on the space shuttle Discovery's external fuel tank, presenting further issues for the orbiter's planned final launch.

Technicians began repair work on Discovery this morning (Nov. 10), and identified the cracks on the aluminum body of the tank. An earlier crack had been discovered in the insulating foam layer that coats the tank.

After a series of delays and glitches prevented the orbiter from launching last week, NASA is aiming to lift off Discovery on a mission to the International Space Station no earlier than Nov. 30.

NASA officials are evaluating images of the cracks to determine how to repair them as the orbiter sits on its launch pad at NASA's Kennedy Space Center in Florida.

"This is still really early on, so the exact repair method and schedule is still being figured out," NASA spokesman Allard Beutel told SPACE.com. "It's just a matter of the repair method and how best to go about it. Right now, we're looking at repair options that can be done at the pad."

Shuttle technicians have repaired similar cracks on external tanks by removing the fractured aluminum and replacing it with a twice-as-thick stringer section, before replacing the foam. But, these repairs have previously only been executed during the external tank production phase.

"We've seen these kinds of things before at the tops of stringers," Beutel said. "They've done repairs to them before, but we've never done them here at Kennedy. They were always done at Michoud."

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www.nasa.gov : Detail of Crack in External Tank Stringer

 

[EarthlingX]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

[youtube]http://www.youtube.com/watch?v=Xy2iKji29H8[/youtube]

NASAtelevision | November 10, 2010

Technicians at Launch Pad 39A at NASA's Kennedy Space Center began the process of repairing a hydrogen gas leak that scrubbed space shuttle Discovery's Nov. 5 launch attempt. STS-133 is now targeted to launch to the International Space Station no earlier than Nov. 30 at 4:02 a.m. Eastern.

[youtube]http://www.youtube.com/watch?v=900J_ODhap4[/youtube]

NASAtelevision | November 10, 2010

He's the guy who, figuratively, pushes "the big red button" to send the shuttle into space. Astronaut Mike Massimino takes you inside the firing room at the Kennedy Space Center to meet Shuttle Launch Director Mike Leinbach in this episode of NASA "Behind the Scenes

[youtube]http://www.youtube.com/watch?v=d5DvW1caEgs[/youtube]

NASAtelevision | November 10, 2010

In this episode of NASA "Behind the Scenes," astronaut Mike Massimino visits the Johnson Space Center's Neutral Buoyancy Laboratory. The world's largest indoor pool is where Al Drew, Tim Kopra, Mike Barratt and Nicole Stott of the STS-133 crew are practicing the mission's planned spacewalks.

 

[EarthlingX]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

www.spaceflightnow.com : Apparent seal problem found in leaking shuttle vent line

BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: November 11, 2010

A leaking hydrogen vent line attachment fitting on the side of the shuttle Discovery's external tank was removed and disassembled overnight, revealing an unevenly compressed internal seal. The quick-disconnect hardware also may have a less concentric fit than pre-fueling measurements indicated. An analysis is underway to determine if the defects are responsible for the gaseous hydrogen leak that grounded Discovery last Friday.

At pad 39A, a worker begins to remove the ground umbilical carrier plate's 7-inch quick disconnect. Credit: NASA

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The ground umbilical carrier plate's 7-inch quick disconnect is removed from the external fuel tank. Credit: NASA

 

[EarthlingX]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

www.nasa.gov : Status of GUCP Work, ET Foam and Stringer Cracks

Thu, 11 Nov 2010 16:30:36 GMT

Overnight, crews removed space shuttle Discovery’s ground umbilical carrier assembly, or GUCA, which includes the flight seal, the 7-inch quick disconnect, or QD and the carrier plate, known as the GUCP, as they continue working to investigate the leak.

Teams performed an initial inspection of the flight seal and quick disconnect prior to sending them to labs for a thorough inspection. Data collected from the initial inspections will be evaluated today by the investigation team. Engineering saw some areas of interest that are being further evaluated. Based on this evaluation, crews could be ready to install a new GUCA on Friday.

Also, technicians have removed external tank foam insulation that cracked during initial loading operations for space shuttle Discovery’s launch attempt on Nov. 5. After foam removal, two cracks were found on a section of the tank’s metal exterior. The cracks were found on the stringer, which is the aluminum strip that forms the section between the Liquid Oxygen tank and the Liquid Hydrogen tank. Stringers provide structural integrity to the intertank. The cracks are approximately nine inches long and were found at the top of one of the stringers beneath the area of foam that cracked during tanking. The cracks in the stringer moved the metal outward sufficiently to dislocate the foam. Engineers are reviewing images of the cracks to determine the best possible repair method, which would be done at Launch Pad 39A.

The stringers are manufactured using a lighter weight, stronger material of Aluminum Lithium, which was initially incorporated with the Super Light Weight Tank on ET-96 and first flown on STS-91. While the material is stronger and lighter in weight, it is more brittle and has resulted in increased cases of cracked stringers in the areas noted.

The cracked stringer section matches well with the area of foam that cracked, which indicates the stringer crack was the root cause of the foam crack. Analysis shows the intertank has sufficient structural capability for the launch and ascent environments with the cracks in a single stringer. Although the foam was firmly attached to the damaged structure, it is undesirable to launch in this configuration. This area is clearly visible during the pre-launch inspections and would have been detected by the final inspection team.

Crews have repaired similar cracks during external tank production by installing a second piece of aluminum for reinforcement on top of the cracked area before replacing the foam insulation. This piece frequently is referred to as a "doubler." The repair plan being put into effect is a known one consisting of cutting out the cracked section and replacing it with an available piece that matches its size. A doubler will be inserted before the mounting rivets to complete the repair.

BX foam then will be formed over the newly repaired stringer and will require about four days to cure.

Exact schedules and repair options still are being evaluated. Engineers will meet Friday to discuss the status of the three repair activities underway, the external tank stringer and foam repair, the ground umbilical carrier plate and the cockpit panel L4 removal and replacement.

Intertank Facts:

· The intertank is composed of eight mechanically fastened panels (not welded). Six of these panels have external stringers. Each of these six panels has 18 stringers for a total of 108. These stringers provide buckling resistance and load distribution, providing structural integrity for the intertank

· Each stringer is about 21.5 feet long

· The ends of each stringer are flush with the foam on the LH2 and LO2 tank sections

 

[EarthlingX]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

http://www.nasaspaceflight.com : STS-133: Closing in on GUCP root cause – ET repair at pad still positive

November 11th, 2010 by Chris Bergin

Concentricity measurements on the removed flight seal on the Ground Umbilical Carrier Plate (GUCP) have found at least one of the potential root causes for last Friday’s leak, with a forward plan to install a replacement carrier plate and seal ahead of a potential Tanking Test. Plans are also being worked to install a doubler to the cracked intertank stringer, whilst at the pad.

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The plan to repair the area still concentrates around in-situ work at the pad, allowing engineers to install a second piece of aluminum known as a doubler to the damaged area – as was previously conducted on ET-138 during its production at the Michoud Assembly Facility (MAF).

BX foam then will be sprayed over the newly repaired stringer, requiring approximately four days to cure. However, Friday’s key meeting will decide on the viability of the plan, with previous notes stressing the need for an environment tent/hood to be placed over the worksite, as a condition of spraying foam on to the tank.

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[Gravity_Ray]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

Got a bad feeling this is going back to the VAB.

 

[3488]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

I think at the moment, this still looks like a repair that can be done on the pad, but I agree, the likelihood of Discovery returning to the VAB is looking more likely, with a launch a little later in December.

The engineers working on this though are pretty smart, so on pad repair still cannot be ruled out (hopefully).

Andrew Brown.

 

[EarthlingX]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

http://www.nasa.gov : More Discovery External Tank GUCP Measurements and Stringer Crack Analysis

Fri, 12 Nov 2010 22:54:38 GMT


Image above: On Launch Pad 39A at NASA's Kennedy Space Center in Florida, workers begin to install a new ground umbilical carrier plate, or GUCP, on space shuttle Discovery's external fuel tank.
Photo Credit: NASA/Troy Cryder

Over the weekend at Launch Pad 39A at NASA’s Kennedy Space Center in Florida, technicians will take additional measurements to ensure the best possible alignment of the newly installed ground umbilical carrier plate (GUCP) on space shuttle Discovery’s external fuel tank. Teams will evaluate data and now expect to begin installing the flight seal and quick disconnects on Monday, Nov. 15.

Engineers met today to discuss upcoming work to repair cracks in Discovery’s external tank intertank section. During foam removal and inspection of adjacent stringers to the one with two 9-inch cracks, technicians today identified an approximately 3-inch crack on the left-hand adjacent stringer. This was not an unexpected result since the load was most likely transferred to the adjacent stringer when both sides of the original stringer cracked during tanking operations for Discovery’s scrubbed launch attempt on Nov. 5. Teams will build and use existing structural math models to understand the loading at the interface. Stringers are aluminum support strips on the outside of the external tank that form the section between the inside liquid oxygen tank and the liquid hydrogen tanks.

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http://www.spaceflightnow.com : Second cracked stringer found in Discovery's tank

BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: November 12, 2010;
Updated @ 8:40 p.m. to add NASA statement and more details

Engineers removed additional foam insulation near a cracked structural support strip, or stringer, in the shuttle Discovery's external tank and found yet another crack in an adjacent stringer, NASA officials confirmed late Friday.

A closeup view of a newly discovered crack in the shuttle's external tank.
Credit: NASA

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http://www.nasaspaceflight.com : STS-133: Third crack found on ET-137 as managers debate forward plan

November 12th, 2010 by Chris Bergin

A third crack has been found on a stringer adjacent to the two original cracks on Discovery’s External Tank (ET-137). The latest crack was found on the far left of removed Thermal Protection System (TPS) foam on the flange area between the Intertank and the LOX tank, but appears to have suffered less stress than its two neighbors.

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Posted on November 12, 2010
by NASAKennedy

Workers began to install a new ground umbilical carrier plate on Discovery's external tank this morning.

STS-133: Techs prepare to work inside the intertank to further analyze the 2 cracks found on the metal exterior.

 

[SpaceKiwi]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

A great run-down of the current issues, Guys.

No more parts coming off the line, so they have little choice but to get this one repaired. If it were me I think I'd haul the Stack back to the VAB, remove the ET and start again. I know these are relatively routine running repairs but I'd hate to see a catastrophic failure when we are so close to an incident-free end to the Shuttle Program.



SK

 

[spacenerd101]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

What do you guys think is the probability that it'll launch the morning of the 30th? The more I read the more I think it's less and less likely.

 

[EarthlingX]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

www.spaceflightnow.com : Fourth crack found on shuttle Discovery's external tank

BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: November 15, 2010;
Updated @ 4:30 p.m. with approval to install replacement GUCP quick-disconnect

KENNEDY SPACE CENTER, FL--Engineers inspecting the shuttle Discovery's external tank have found a fourth crack in the structural ribs, or stringers, making up the outer skin of the compartment between the liquid oxygen and hydrogen sections.

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A replacement ground umbilical carrier plate, or GUCP, already has been installed on the tank and measurements show its alignment is near perfect. The replacement quick-disconnect fitting will be oriented, or "clocked," to ensure the best possible circular alignment, or concentricity, and the tightest possible seal.

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Over the weekend, a fourth crack was found in the left-side stringer, known as S-6-2, sources said. No cracks were found in stringers on the right side.

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While crack repairs are not unusual, the cracks in Discovery's tank are the first to be found at the launch pad, where access is more difficult. An environmental enclosure has been erected around the known damage site to facilitate repairs and the eventual application of fresh foam insulation.

It's not yet known whether more defects remain to be discovered, but engineers are optimistic high-tech instruments capable of detecting damage beneath the foam can be used to find any additional problems.

 

[EarthlingX]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

www.nasaspaceflight.com : STS-133: Preliminary plan for six day countdown and Tanking Test discussed

November 16th, 2010

by Chris Bergin

Providing Discovery’s External Tank (ET-137) can be repaired and cleared for flight in time for the upcoming launch window, managers have created a preliminary plan for a Tanking Test, built into a six day countdown. In order to avoid a slip to next February, managers are focusing on gaining confidence in the intertank’s condition, which may only come via additional inspections.

Discovery continues to track a preliminary NET (No Earlier Than) launch date of November 30 – based on the opening of the next available window – although an actual launch date is likely to remain unset until at least November 22, when a full managerial meeting on the status of Discovery’s tank is held.

Resolving the two main issues with STS-133 – both on the External Tank – will continue to drive the ability for NASA to either push forward towards the short window that runs through the first week of December, or standdown until the next window late in February, in turn delaying STS-134.

The actual repairs of the tank – as it stands – have a fair chance of being resolved in time. However, the required confidence, or Flight Rationale, on the cracks in the tank’s stringers, remains the main question which currently lacks a root cause.

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[trailrider]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

Well, at least they'll have procedures down pat for a whole bunch of future flights. Wait a minute! Hold it! There are only going to be [two][one] future flight. (Congress, please select one...) :?

Better they should get things checked and fixed for sure, even if it means slipping until February 2011.

 

[Gravity_Ray]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

VAB for sure.

 

[mr_mark]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

They need to figure this out. Spacex's flight is scheduled for December 7th and must use the same recovery boats.

 

[MeteorWayne]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

HOUSTON -- NASA managers will hold a news conference no earlier than 5 p.m. CST on Monday, Nov. 22, at the agency's Johnson Space Center in Houston to discuss the next space shuttle mission, STS-133, which was delayed on Nov. 5.

NASA officials will announce the status of repairs to a leaking hydrogen system that caused the initial delay. They also will discuss the cracks on the tops of two, 21-foot-long support beams, called stringers, on the exterior of the shuttle's external fuel tank in an area known as the intertank. The next launch window for space shuttle Discovery and six NASA astronauts begins Nov. 30.

The briefing participants are:

-- Bill Gerstenmaier, associate administrator for Space Operations

-- John Shannon, Space Shuttle Program manager

The news conference will air live on NASA Television and the agency's website.

Live status updates will be provided during the meeting via the NASA News Twitter feed. To access the feed, go to the nasa.gov homepage or visit:

http://www.twitter.com/nasa

For NASA TV streaming video, downlink and scheduling information, visit:

http://www.nasa.gov/ntv

For STS-133 crew and mission information, visit:

http://www.nasa.gov/shuttle

 

[MeteorWayne]

Re: STS-133 Pre Launch Discussion ( NET Nov 30, ~4AM EST)

MEDIA ADVISORY : M10-165 NASA Reschedules Shuttle Launch Status Meeting, Discovery's Launch No Earlier Than Dec. 3 HOUSTON -- NASA managers have postponed a launch status meeting and news conference planned for Monday, Nov. 22. The events were rescheduled after a Space Shuttle Program meeting Thursday determined more analysis is needed before proceeding toward the launch of space shuttle Discovery on its STS-133 mission.

The Program Requirements Control Board (PRCB) identified the analysis and repairs required to safely launch Discovery. This analysis will be done during the next five days and reviewed at a special PRCB on Wednesday, Nov. 24. Pending a successful review of the flight rationale at that meeting, a launch status briefing will be held with senior NASA managers on Monday, Nov. 29.

Work has been under way to fix a leaking hydrogen system that caused the initial delay, and to repair cracks atop two 21-foot-long support beams, called stringers, on the exterior of the shuttle's external fuel tank.

The Kennedy Space Center will begin the launch countdown no earlier than Nov. 30. That would support a launch attempt for Discovery no earlier than Dec. 3 at approximately 2:52 a.m. EST.

For STS-133 crew and mission information, visit:

http://www.nasa.gov/shuttle

 

[EarthlingX]

Re: STS-133 Pre Launch Discussion ( NET Dec 3)

[youtube]http://www.youtube.com/watch?v=NWupQkE8WW8[/youtube]

NASAtelevision | November 19, 2010

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[EarthlingX]

Re: STS-133 Pre Launch Discussion ( NET Dec 3)

www.nasaspaceflight.com : ET-137 ahead on repairs as Cain dismisses schedule pressure claims

November 21st, 2010

by Chris Bergin

With the focus firmly placed on the repairs, inspections and required flight rationale for the LOX/Intertank flange stringers, hopes have being raised of positive outcome by the end of the coming week. However, deputy Space Shuttle Program (SSP) LeRoy Cain dismissed internal rumors of schedule pressure to avoid a slip to next year, by noting the Program is adamant they won’t fly until they are ready.

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[MeteorWayne]

Re: STS-133 Pre Launch Discussion ( NET Dec 3)

NASA has delayed the final launch of the space shuttle Discovery to no earlier than mid-December, and could potentially postpone the flight to February pending a final review, agency officials have confirmed.

Top shuttle program managers met today (Nov. 24) to review recent repairs to Discovery's massive external fuel tank. Based on the discussion, NASA officials decided to push the launch attempt to at least Dec. 17, if not into the next launch window in February.

http://www.space.com/missionlaunches/sp ... 01124.html

NASA Release:

NASA managers have targeted space shuttle Discovery's launch for no earlier than Dec. 17. Shuttle managers determined more tests and analysis are needed before proceeding with the STS-133 mission. The launch status meeting planned for Monday, Nov. 29, has been postponed and will be rescheduled.

The Program Requirements Control Board reviewed on Wednesday repairs and engineering evaluations associated with cracks on two 21-foot-long, U-shaped aluminum brackets, called stringers, on the shuttle's external tank. Managers decided the analysis and tests required to launch Discovery safely are not complete. The work will continue through next week.

The next status review by the PRCB will be Thursday, Dec. 2. If managers clear Discovery for launch on Dec. 17, the preferred time is about 8:51 p.m. EST.

 

[vulture4]

Re: STS-133 Pre Launch Discussion ( NET Dec 3)

This is not a fatigue failure where stociastic processes can occur. The failure was deterministic. The strigers exceeded ultimate strength. They need to do a tanking test. If they roll back, they need a tanking test first. Since the failure is deterministic, if there are any other overstressed stringers, they will fail. Then they can inspect them. One way would be ultrasound from inside the intertank. If any are cracked or improperly installed, they can be replaced. Then they are good to go.

 

[job1207]

Re: STS-133 Pre Launch Discussion ( NET Dec 3)

??? could you translate that to regular english?

 

[montmein69]

Re: STS-133 Pre Launch Discussion ( NET Dec 17)

Currently the Dec 3 option is no more valide.

A new launch window is evaluated : NET Dec 17.

Although STS-133 is threatening to move into next year, NASA managers will continue to evaluate the opportunity to make a late December window.

http://www.nasaspaceflight.com/2010/11/ ... rationale/

 

[MeteorWayne]

Re: STS-133 Pre Launch Discussion ( NET Dec 3)

As stated 4 posts and 6 days ago...