Author Topic: STS-120 Processing Latest (Read 153105 times)

Chris Bergin · « **Reply #520 on:** 09/17/2007 01:19 pm »

Sorry to say but STS-120's October launch window is now threatened by the strut problem.

Rollover unlikely to be much before the end of the month.

shuttlefan · « **Reply #521 on:** 09/17/2007 01:28 pm »

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Chris Bergin - 17/9/2007 8:19 AM

Sorry to say but STS-120's October launch window is now threatened by the strut problem.

Rollover unlikely to be much before the end of the month.

I know it's been posted earlier but when is the next possible launch date after the October window?

Chris Bergin · « **Reply #522 on:** 09/17/2007 01:32 pm »

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shuttlefan - 17/9/2007 2:28 PM

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Chris Bergin - 17/9/2007 8:19 AM

Sorry to say but STS-120's October launch window is now threatened by the strut problem.

Rollover unlikely to be much before the end of the month.

I know it's been posted earlier but when is the next possible launch date after the October window?

It can still launch in the window. It goes on through half of November.

psloss · « **Reply #523 on:** 09/17/2007 01:36 pm »

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Chris Bergin - 17/9/2007 9:32 AM

It can still launch in the window. It goes on through half of November.

What constrains things after mid-November? The only thing I've heard of is beta angle and that is only mid-December through end of December.

shuttlefan · « **Reply #524 on:** 09/17/2007 01:43 pm »

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psloss - 17/9/2007 8:36 AM

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Chris Bergin - 17/9/2007 9:32 AM

It can still launch in the window. It goes on through half of November.
What constrains things after mid-November? The only thing I've heard of is beta angle and that is only mid-December through end of December.

I can't understand what constrains things, because all the missions have to proceed in sequence now. We're NOT talking about a scenario where they'd fly STS-122 first or anything like that....

psloss · « **Reply #525 on:** 09/17/2007 01:54 pm »

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shuttlefan - 17/9/2007 9:43 AM

I can't understand what constrains things, because all the missions have to proceed in sequence now. We're NOT talking about a scenario where they'd fly STS-122 first or anything like that....

Right, but we're talking about a scenario where 10A/120 is still on the ground in mid-November. This is hypothetically similar to the STS-117 delay -- everything gets pushed back, but when 120 is ready, it flies and it flies first. A delay to 120 doesn't change the prerequisite that 10A/120 fly before 1E/122.

The question is what other temporary showstoppers there are besides beta angle. (And Soyuz / Progress / ATV conflicts, though the next Soyuz crew rotation and I believe the first ATV are currently "deconflicted.")

ChrisGebhardt · « **Reply #526 on:** 09/17/2007 02:12 pm »

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psloss - 17/9/2007 9:36 AM

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Chris Bergin - 17/9/2007 9:32 AM

It can still launch in the window. It goes on through half of November.
What constrains things after mid-November? The only thing I've heard of is beta angle and that is only mid-December through end of December.

There's an Atlas V rocket launch scheduled for November 7 from Cape Canaveral. Right now, in terms of the range, this is the only confliction showing up.

I'm not so much looking at the constraints in this launch window, as I am with the processing time for STS-122. If what I've heard here before is correct, a launch after November 1 wouldn't really provide enough time to turn 39A around in time to support 122 in the December window. This is ironic considering the forward plan to preserve the December window for Atlantis.

Chris Bergin · « **Reply #527 on:** 09/17/2007 02:46 pm »

Bottom line is we won't know the new rollover date until midweek. Depends on when the Vendor arrives (Tuesday night at the moment) and the seals, and the ETA for the repair to be completed.

Lee Jay · « **Reply #528 on:** 09/17/2007 02:56 pm »

So, this seems to be a seal issue. Is there any way to know just how certain they are that the seal is the problem? Did they disassemble the thing already? A leak through a seal doesn't necessarily mean the seal is at fault.

Chris Bergin · « **Reply #529 on:** 09/17/2007 07:15 pm »

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Chris Bergin - 17/9/2007 2:19 PM

Sorry to say but STS-120's October launch window is now threatened by the strut problem.

Rollover unlikely to be much before the end of the month.

And this is now the case following meetings (that they'll do a changeout). Will be a change to the first launch opportunity.

psloss · « **Reply #530 on:** 09/17/2007 09:05 pm »

NASA.gov is now reporting the decision on the repair work:
http://www.nasa.gov/mission_pages/shuttle/main/index.html

Namechange User · « **Reply #531 on:** 09/17/2007 09:12 pm »

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Lee Jay - 17/9/2007 9:56 AM

So, this seems to be a seal issue. Is there any way to know just how certain they are that the seal is the problem? Did they disassemble the thing already? A leak through a seal doesn't necessarily mean the seal is at fault.

In this case it pretty much does. The strut housing is certainly not cracked so that leaves very few other options. There are no reports of large scratches in the piston of the strut either.

Lee Jay · « **Reply #532 on:** 09/17/2007 09:22 pm »

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OV-106 - 17/9/2007 3:12 PM

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Lee Jay - 17/9/2007 9:56 AM

So, this seems to be a seal issue. Is there any way to know just how certain they are that the seal is the problem? Did they disassemble the thing already? A leak through a seal doesn't necessarily mean the seal is at fault.

In this case it pretty much does. The strut housing is certainly not cracked so that leaves very few other options. There are no reports of large scratches in the piston of the strut either.

Okay, good. Ram scoring, out-of-roundness, and out-of-spec dimensions, and the same for the plate that supports the seal are also potential causes. I'm guessing these things see some pretty horrendous thermal cycles so dimensional changes are possible over time, even if they are stress-relieved. I'm glad you all looked into the scoring issue and I do hope the seals solve the problem.

This is the high-pressure seal, is it not?

MKremer · « **Reply #533 on:** 09/17/2007 09:34 pm »

BTW, it may help to visualize the problem area by relating the landing gear assembly to an automobile shock absorber. The bottom part of the strut (the cylinder part with the wheels, tires, and brakes attached to it) is the piston portion. The upper strut contains the hydraulic fluid and seals around the piston.

Chris Bergin · « **Reply #534 on:** 09/17/2007 09:36 pm »

Our update: http://www.nasaspaceflight.com/content/?cid=5231

jarthur · « **Reply #535 on:** 09/17/2007 11:12 pm »

Radio in Oklahoma quotes NASA sources indicating a Jan launch at the earliest. Here's to hoping repairs go smoothly and STS-120 gets off the ground earlier

Chris Bergin · « **Reply #536 on:** 09/17/2007 11:17 pm »

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jarthur - 17/9/2007 12:12 AM

Radio in Oklahoma quotes NASA sources indicating a Jan launch at the earliest. Here's to hoping repairs go smoothly and STS-120 gets off the ground earlier

Inaccurate.

jarthur · « **Reply #537 on:** 09/17/2007 11:31 pm »

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Chris Bergin - 17/9/2007 5:17 PM

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jarthur - 17/9/2007 12:12 AM

Radio in Oklahoma quotes NASA sources indicating a Jan launch at the earliest. Here's to hoping repairs go smoothly and STS-120 gets off the ground earlier

Inaccurate.

I hope so. the rumor originates from abc news.

Chris Bergin · « **Reply #538 on:** 09/17/2007 11:37 pm »

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jarthur - 18/9/2007 12:31 AM

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Chris Bergin - 17/9/2007 5:17 PM

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jarthur - 17/9/2007 12:12 AM

Radio in Oklahoma quotes NASA sources indicating a Jan launch at the earliest. Here's to hoping repairs go smoothly and STS-120 gets off the ground earlier

Inaccurate.

I hope so. the rumor originates from abc news.

Is that who they accredited on the radio?

All I've seen on ABC is the usual syndication of the short AP wire story: http://abcnews.go.com/Technology/wireStory?id=3614457

But regardless, no NASA source is going to be telling anyone that this is Jan at the earliest.

The only threat is to the opening week of the regular window, so they may get about a 14 day window starting end of October (and still they may get to catch some of this back if the repair goes well, Pad flow etc.)

Now if something went badly wrong (and that has to happen) to the point where there's a month delay etc. then they shoot for the December window which 122 was due to launch in.

For them to come up with Jan at the earliest does not appear to be based in facts. Sounds like some radio editor at that radio station got his/hers wires badly crossed.

jarthur · « **Reply #539 on:** 09/17/2007 11:46 pm »

It was one of those abc news breaks that they do at the top of the hour.