Author Topic: ISS Solar Array Tear - What Next? (Read 49439 times)

ApolloLee · « **on:** 10/30/2007 04:21 pm »

NYC777 - 30/10/2007 10:18 AM

In my opinion the only way to fix this is to retract and have an EVA to cut the guide wire that hanging the array up. Either that or retract and then redeploy hoping that the wire will free itself.

Any one disagree?

Just remember how much a pain retraction with this array was on STS-116.... I think if we can avoid a full retraction, we should.

ApolloLee · « **Reply #1 on:** 10/30/2007 04:23 pm »

ApolloLee - 30/10/2007 1:18 PM

Some interesting foreboding in this very thread before this.... what did I say a few days ago about jinxing things?

"Rollout will be much easier - and it makes sense since the tension required to pull it out is much more painless than reeling it in and worrying about snags."

"Its deploying better than it did retracting. Looks great and hope 4B array does the same!"

"Outstanding. The 116 crew is probably sitting around, scratching their heads wondering 'Why didn't it work that well for us?'"

PSLoss: Wow -- so it's our fault, then, right?

No ... I blame Britney Spears.... Just cause...

Chris Bergin · « **Reply #2 on:** 10/30/2007 04:25 pm »

Thanks David, I was starting to lose hair I don't have with the live thread.

psloss · « **Reply #3 on:** 10/30/2007 04:25 pm »

First us, then Britney...

ApolloLee · « **Reply #4 on:** 10/30/2007 04:25 pm »

So throw off your wild speculation... How is this fixed?

Not acceptable is saying "Have some Starfleet officers in suits beam to the position, fix it with dylithium crystals, then beam out."

Michael Z Freeman · « **Reply #5 on:** 10/30/2007 04:28 pm »

So, is the array foldable "blanket" replaceable ?

DJ Barney

stockman · « **Reply #6 on:** 10/30/2007 04:31 pm »

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ApolloLee - 30/10/2007 1:25 PM

So throw off your wild speculation... How is this fixed?

Not acceptable is saying "Have some Starfleet officers in suits beam to the position, fix it with dylithium crystals, then beam out."

don't be ridiculous... everyone knows you can't use Dylithium to fix solar panels... geesh!!

semi-seriously however, the main question right now is can they leave the array in a half deployed position for any great length of time (ie after shuttle leaves). If not then I see only three possible options.

1) retract and hope/try to get it folded up into a safe config
2) somehow magically figure out how to free it and deploy nominally.
3) remove and eject that side of the solar blanket assembly (I am assuming here you can do that one side at a time without have to throw out the other side that is fully and correctly deployed).

ckiki lwai · « **Reply #7 on:** 10/30/2007 04:33 pm »

I think we will have a very interesting Mission Status Briefing over an hour.

Would they extend the mission even further, will they drop the SARJ inspection or will they leave the solar array alone.
Or do they have to do repairs to the shuttle because there was a MMOD hit?

DaveS · « **Reply #8 on:** 10/30/2007 04:37 pm »

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ckiki lwai - 30/10/2007 6:33 PM
Or do they have to do repairs to the shuttle because there was a MMOD hit?

It hasn't been confirmed that if it was a MMOD hit. Could be a thermal settling of the aluminium brackets on which the impact sensors are mounted on. They're not mounted directly onto the RCC panels but behind them.

Jorge · « **Reply #9 on:** 10/30/2007 04:42 pm »

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ApolloLee - 30/10/2007 12:21 PM

NYC777 - 30/10/2007 10:18 AM

In my opinion the only way to fix this is to retract and have an EVA to cut the guide wire that hanging the array up. Either that or retract and then redeploy hoping that the wire will free itself.

Any one disagree?

Cutting the guide wire would be a big mistake.

punkboi · « **Reply #10 on:** 10/30/2007 04:42 pm »

*Sigh* Good luck and anything solar power-related just hasn't been going hand-in-hand with the ISS...

rdale · « **Reply #11 on:** 10/30/2007 04:53 pm »

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ckiki lwai - 30/10/2007 1:33 PM

Or do they have to do repairs to the shuttle because there was a MMOD hit?

Stop the presses! When / where was a MMOD hit? What sort of damage did it cause?

Lee Jay · « **Reply #12 on:** 10/30/2007 04:56 pm »

Sorry, should have asked this here, I guess.

Could this location be reached using an EVA on the end of the OBSS on either of the arms?

stockman · « **Reply #13 on:** 10/30/2007 04:56 pm »

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rdale - 30/10/2007 1:53 PM

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ckiki lwai - 30/10/2007 1:33 PM

Or do they have to do repairs to the shuttle because there was a MMOD hit?

Stop the presses! When / where was a MMOD hit? What sort of damage did it cause?

Relax.. this was reported on L2 but they are not sure if it was a real MMOD hit or thermal issues that caused a reading. No panic here.

Lee Jay · « **Reply #14 on:** 10/30/2007 04:57 pm »

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rdale - 30/10/2007 11:53 AM

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ckiki lwai - 30/10/2007 1:33 PM

Or do they have to do repairs to the shuttle because there was a MMOD hit?

Stop the presses! When / where was a MMOD hit? What sort of damage did it cause?

The press already ran, and the article is on the front page.

ApolloLee · « **Reply #15 on:** 10/30/2007 05:00 pm »

Official logo for today's proceedings... Should be posted behind Shannon during MSB...

http://www.badastronomy.com/pix/bablog/2006/DontPanic.jpg">

ckiki lwai · « **Reply #16 on:** 10/30/2007 05:29 pm »

Could the P6 en P4 rotate with the P6 arrays not fully extracted?

bobthemonkey · « **Reply #17 on:** 10/30/2007 05:44 pm »

Don't believe so.

On the Solar blankets used on the SAW's, it the material resistant to rips. I.e. once a tear starts (as now) is it contained or will it continue across the panel. (Material science was a distant memory - I can't imagine EVA's needed to put a hole in the tear to stop the stress concentration.

ApolloLee · « **Reply #18 on:** 10/30/2007 05:46 pm »

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ckiki lwai - 30/10/2007 11:29 AM

Could the P6 en P4 rotate with the P6 arrays not fully extracted?

Think so... We've already seen them rotate a bit in the last hour or so...

wannamoonbase · « **Reply #19 on:** 10/30/2007 05:53 pm »

Q: Asked early but no answer yet, can the one side be jettisoned or replaced? Is there any kind of flight spare (understanding that this has huge implications for manifest etc?)

(Perhaps this should be the first question.) Does anyone with ISS experience have a gut feel for whether this is repairable or is it FUBAR?

rdale · « **Reply #20 on:** 10/30/2007 05:58 pm »

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Lee Jay - 30/10/2007 1:57 PM

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rdale - 30/10/2007 11:53 AM

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ckiki lwai - 30/10/2007 1:33 PM

Or do they have to do repairs to the shuttle because there was a MMOD hit?

Stop the presses! When / where was a MMOD hit? What sort of damage did it cause?

The press already ran, and the article is on the front page.

Help me out here -- all I see is that they had indications of a possible MMOD strike... Nothing about any damage that needs repair, let alone even confirming it was MMOD. "Likely" does not mean "100%" -- anyone watching the weather forecasts should know that :cool:

Mike_1179 · « **Reply #21 on:** 10/30/2007 05:59 pm »

Transferred from the FD 8 thread:

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NYC777 - 30/10/2007 2:43 PM

Here's a what if...and I know that it's very hypothetical. Can they extend the remaining 6 bays knowing full well that there could be some more damage and utilize the arrays in that configuration?

They can do whatever they want, that's the beauty of allowing smart people to analyze the situation and determine what's best when problems arise.

However, every decision has risks and benefits. I'm reasonably sure this is one plan they are looking at, but they need to determine what happened and how bad the damage is. That way, they can make a more accurate assessment of the likelyhood of further damage happening.

The worst thing they can do is make a situation worse by guessing. Instead, they'll work the problem and find the right solution. The right solution might very well involve redeploying this damaged SAW, but only if they've got some confidence - based on real data, not just gut feelings - that it will work and not make the situation worse.

bobthemonkey · « **Reply #22 on:** 10/30/2007 06:03 pm »

wannamoonbase, the array is designed for on-orbit replacement. The problem is that a flight spare does not exist and would be a major task to complete the replacement. Even if it did, it would not be light, and would need some work on the manifest.

Jorge · « **Reply #23 on:** 10/30/2007 06:05 pm »

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rdale - 30/10/2007 1:58 PM

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Lee Jay - 30/10/2007 1:57 PM

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rdale - 30/10/2007 11:53 AM

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ckiki lwai - 30/10/2007 1:33 PM

Or do they have to do repairs to the shuttle because there was a MMOD hit?

Stop the presses! When / where was a MMOD hit? What sort of damage did it cause?

The press already ran, and the article is on the front page.

Help me out here -- all I see is that they had indications of a possible MMOD strike... Nothing about any damage that needs repair, let alone even confirming it was MMOD. "Likely" does not mean "100%" -- anyone watching the weather forecasts should know that :cool:

No confirmation possible at this time. All they have is a 2.7 g indication on one WLES sensor, could be an impact, could be something else. No one knows, and no one will know until Late Inspection. Speculation is pointless.

rdale · « **Reply #24 on:** 10/30/2007 06:11 pm »

Thanks - I'm at work so not getting as much NASATV time as desired, so I'm not sure if reports of MMOD damage requiring repair would be coming from a WAG or someone in the know. Might need to start using the "ignore" feature...

NYC777 · « **Reply #25 on:** 10/30/2007 07:42 pm »

My gues for the Solar Array repair...extend the mission by another day or tw to support a 6th EVA specifically to repair the Array. I thnik that they'll do a partial retract so that EVs can get up to to the problem area to cut the guide wire or to release the hang up. That's my opinion but let's see what these guys come up with in the next day or so.

rdale · « **Reply #26 on:** 10/30/2007 07:54 pm »

Did you watch the press conference?

kraisee · « **Reply #27 on:** 10/30/2007 08:38 pm »

I have to say, these array problems and SARJ issues are actually very valuable in some ways. These events, and many others, are all helping build an astonishing library of do's and don'ts which NASA will be able to call upon for decades to come.

These incidents will help refine the design of similar systems on future hardware and serve as an incredibly dynamic test-bed for the space engineering community.

I am always impressed with the vast amount of pure data and knowledge which NASA seems to be able to extract from such events, and am always further impressed by the understanding these guys and gals have to be able to work around such issues and typically continue truckin' unhindered after such events.

As an engineer myself, this work is just fascinating to watch.

Ross.

Jorge · « **Reply #28 on:** 10/30/2007 08:49 pm »

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NYC777 - 30/10/2007 3:42 PM

My gues for the Solar Array repair...extend the mission by another day or tw to support a 6th EVA specifically to repair the Array. I thnik that they'll do a partial retract so that EVs can get up to to the problem area to cut the guide wire or to release the hang up. That's my opinion but let's see what these guys come up with in the next day or so.

Cutting the guide wire would be a big mistake.

JimO · « **Reply #29 on:** 10/30/2007 08:51 pm »

SA access and repair?

Sounds also like a good opportunity for a third crewmember out on EVA.

Remember, we've done it once already.

HIPAR · « **Reply #30 on:** 10/30/2007 08:51 pm »

Will the array still generate power with the tear being there? If so can they just use it as is?

--- CHAS

nathan.moeller · « **Reply #31 on:** 10/30/2007 08:53 pm »

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HIPAR - 30/10/2007 4:51 PM

Will the array still generate power with the tear being there? If so can they just use it as is?

--- CHAS

The array is operating at 97% of full power since the electrical wires are intact. Some of the solar cells are shot but it's okay. Like Suffredini said...it's there for power...not to look pretty.

psloss · « **Reply #32 on:** 10/30/2007 08:59 pm »

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HIPAR - 30/10/2007 5:51 PM

Will the array still generate power with the tear being there? If so can they just use it as is?

As Nathan wrote, it is generating power; as was noted in the status briefing, one of the problems with leaving it "as-is" is structural. The system can't be operated normally in the current configuration for things like SARJ rotation, which reduces the amount of power the port-side arrays would be able to generate.

Edit -- JimO's recent post also notes other issues touched on in the briefing:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=10531&posts=655#M205344

nathan.moeller · « **Reply #33 on:** 10/31/2007 12:15 am »

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psloss - 30/10/2007 4:59 PM

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HIPAR - 30/10/2007 5:51 PM

Will the array still generate power with the tear being there? If so can they just use it as is?

As Nathan wrote, it is generating power; as was noted in the status briefing, one of the problems with leaving it "as-is" is structural. The system can't be operated normally in the current configuration for things like SARJ rotation, which reduces the amount of power the port-side arrays would be able to generate.

Edit -- JimO's recent post also notes other issues touched on in the briefing:
http://forum.nasaspaceflight.com/forums/thread-view.asp?tid=10531&posts=655#M205344

Correct. The mast can only retain about 10% of its structural integrity when not fully deployed (depending on how far out it is). But you certainly can't rotate the SARJ if that sucker isn't fully extended. That's the big problem right now. They can rotate the BGAs (beta-gimbal assemblies) to track the sun but that's still a severe power shortfall. It's an issue that needs to be worked out and soon. Columbus and Kibo need that power, even if they're just sitting there.

ehartwell · « **Reply #34 on:** 10/31/2007 12:22 am »

[big]Tear on dotted line?[/big]

Medium-high resolution photos have been posted: http://spaceflight.nasa.gov/gallery/images/shuttle/sts-120/flightday08/ndxpage1.html

Here's a closeup of the tear. This looks like the kind of thing duct tape was invented for.

It's hard to tell for sure, but what looks like a small box at the top is probably just the strap material folded back.

nathan.moeller · « **Reply #35 on:** 10/31/2007 12:24 am »

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ehartwell - 30/10/2007 8:22 PM

[big]Tear on dotted line?[/big]

Medium-high resolution photos have been posted: http://spaceflight.nasa.gov/gallery/images/shuttle/sts-120/flightday08/ndxpage1.html

Here's a closeup of the tear. This looks like the kind of thing duct tape was invented for.

It's hard to tell for sure, but what looks like a small box at the top is probably just the strap material folded back.

Wow thanks! Great shot. It looks almost as if it came 'unzipped,' if you will. Now, probably a stupid question, but assuming an EVA crewmember could access the site, could the tear actually be fixed? Or will it have to be left as-is or replaced to deploy the array?

Jim · « **Reply #36 on:** 10/31/2007 12:33 am »

duct tape

Andrewwski · « **Reply #37 on:** 10/31/2007 12:35 am »

You know, I didn't want to mention it when I first saw the tear, but I have to say duct tape was the first thing that popped into my mind...

shuttle_buff · « **Reply #38 on:** 10/31/2007 12:41 am »

I really think Boeing has some responsiblity here. They built the solar array and they know how it should work. If you asked me (with 25 years in the military business) who needs to address this it's Boeing. It's not NASA.

Avron · « **Reply #39 on:** 10/31/2007 12:46 am »

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shuttle_buff - 30/10/2007 9:41 PM

I really think Boeing has some responsiblity here. They built the solar array and they know how it should work. If you asked me (with 25 years in the military business) who needs to address this it's Boeing. It's not NASA.

Good thing Raytheon or LMT was in involved...

Jim · « **Reply #40 on:** 10/31/2007 12:48 am »

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shuttle_buff - 30/10/2007 9:41 PM

I really think Boeing has some responsiblity here. They built the solar array and they know how it should work. If you asked me (with 25 years in the military business) who needs to address this it's Boeing. It's not NASA.

Lockheed built the array

Lee Jay · « **Reply #41 on:** 10/31/2007 12:48 am »

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Andrewwski - 30/10/2007 7:35 PM

You know, I didn't want to mention it when I first saw the tear, but I have to say duct tape was the first thing that popped into my mind...

Kapton, if anything.

The hinge itself appears to have broken.

Jim · « **Reply #42 on:** 10/31/2007 12:49 am »

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Lee Jay - 30/10/2007 9:48 PM

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Andrewwski - 30/10/2007 7:35 PM

You know, I didn't want to mention it when I first saw the tear, but I have to say duct tape was the first thing that popped into my mind...

Kapton, if anything.

which is space duct tape

Avron · « **Reply #43 on:** 10/31/2007 12:51 am »

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Lee Jay - 30/10/2007 9:48 PM

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Andrewwski - 30/10/2007 7:35 PM

You know, I didn't want to mention it when I first saw the tear, but I have to say duct tape was the first thing that popped into my mind...

Kapton, if anything.

The hinge itself appears to have broken.

or ripped???

shuttle_buff · « **Reply #44 on:** 10/31/2007 12:52 am »

No,

Boeing was the MAJOR contributor to the array.

How that works out to Prime Contractor, Sub Prime and so forth I don't know and don't care.

Boeing built the array part the IS the problem.

Regards,

Lee Jay · « **Reply #45 on:** 10/31/2007 12:56 am »

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Avron - 30/10/2007 7:51 PM

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Lee Jay - 30/10/2007 9:48 PM

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Andrewwski - 30/10/2007 7:35 PM

You know, I didn't want to mention it when I first saw the tear, but I have to say duct tape was the first thing that popped into my mind...

Kapton, if anything.

The hinge itself appears to have broken.

or ripped???

Yeah...that piece appears to have separated from the substrate.

shuttle_buff · « **Reply #46 on:** 10/31/2007 12:56 am »

What company built the hinge?

Avron · « **Reply #47 on:** 10/31/2007 01:01 am »

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shuttle_buff - 30/10/2007 9:56 PM

What company built the hinge?

The hunt is on...

Jim · « **Reply #48 on:** 10/31/2007 01:08 am »

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shuttle_buff - 30/10/2007 9:52 PM

No,

Boeing was the MAJOR contributor to the array.

How that works out to Prime Contractor, Sub Prime and so forth I don't know and don't care.

Boeing built the array part the IS the problem.

Regards,

No, Lockheed built the array and supplied it to Rocketdyne which is now part of P&W

http://www.lockheedmartin.com/news/press_releases/2006/MassiveLockheedMartinSolarArraysBeg.html

Lee Jay · « **Reply #49 on:** 10/31/2007 01:08 am »

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Jim - 30/10/2007 7:49 PM

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Lee Jay - 30/10/2007 9:48 PM

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Andrewwski - 30/10/2007 7:35 PM

You know, I didn't want to mention it when I first saw the tear, but I have to say duct tape was the first thing that popped into my mind...

Kapton, if anything.

which is space duct tape

It's super-duper high-temperature electrical tape down here. I guess the cost of the material is not relevant when your transportation costs exceed $10,000/kg, but down here it's so expensive that I don't use if if I don't need to. It is terrific stuff, but it's also not that easy to work with. I can't imagine trying to apply a lot of it, using EVA gloves, on a flexible array, with nothing to push against. It wouldn't be easy.

I'll definitely be interested to see what they come up with to eventually tension this array.

Jim · « **Reply #50 on:** 10/31/2007 01:12 am »

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shuttle_buff - 30/10/2007 9:56 PM

What company built the hinge?

There is no hinge, the material is folded. The "hinge" is the array which LM built.

Jim · « **Reply #51 on:** 10/31/2007 01:13 am »

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Lee Jay - 30/10/2007 10:08 PM

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Jim - 30/10/2007 7:49 PM

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Lee Jay - 30/10/2007 9:48 PM

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Andrewwski - 30/10/2007 7:35 PM

You know, I didn't want to mention it when I first saw the tear, but I have to say duct tape was the first thing that popped into my mind...

Kapton, if anything.

which is space duct tape

It's super-duper high-temperature electrical tape down here. I guess the cost of the material is not relevant when your transportation costs exceed $10,000/kg, but down here it's so expensive that I don't use if if I don't need to. It is terrific stuff, but it's also not that easy to work with. I can't imagine trying to apply a lot of it, using EVA gloves, on a flexible array, with nothing to push against. It wouldn't be easy.

I'll definitely be interested to see what they come up with to eventually tension this array.

It is the same tape used to capture the bearing filings

shuttle_buff · « **Reply #52 on:** 10/31/2007 01:16 am »

I've been in this business too long. I know too much! One day soon I could die due to old age.

Is 48 old?

Jim · « **Reply #53 on:** 10/31/2007 01:20 am »

just one year older than me and I am not old. Been the space business 24 years, USAF, NASA and commercial.

CessnaDriver · « **Reply #54 on:** 10/31/2007 01:24 am »

If a stable way to work on it is possible...

Sewn maybe??
Staples?

rdale · « **Reply #55 on:** 10/31/2007 01:27 am »

THe press conference already mentioned sewing, or folding them up and using one less array on each side, etc.

Lee Jay · « **Reply #56 on:** 10/31/2007 01:28 am »

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Jim - 30/10/2007 8:12 PM

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shuttle_buff - 30/10/2007 9:56 PM

What company built the hinge?

There is no hinge, the material is folded. The "hinge" is the array which LM built.

It sure looks like the hinge is of a different material, fastened (adhesively?) to the Kapton substrate.

http://spaceflight1.nasa.gov/gallery/images/station/crew-14/hires/iss014e10084.jpg

davcbow · « **Reply #57 on:** 10/31/2007 01:45 am »

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shuttle_buff - 30/10/2007 10:16 PM

I've been in this business too long. I know too much! One day soon I could die due to old age.

Is 48 old?

Better not be, I'm 48 too...

yoda · « **Reply #58 on:** 10/31/2007 01:45 am »

If the two sides of the hinge could be aligned, maybe a wire or thin rod could be inserted to reattach the ripped or separated segment, like a long door pin. Could an EVA accomplish this?

Is it possible the solar array panels were misaligned when stowed for movement, then as the panels were pulled out accordian style, the hinge was caught on part of its stowage box, causing the rip?

shuttlelegs · « **Reply #59 on:** 10/31/2007 01:55 am »

Is this the end of line of such a solar array ? More rigid ones such as the ones which replaced the Hubbles solar arrays more likely to be used in the future if the need appears

rdale · « **Reply #60 on:** 10/31/2007 02:05 am »

I can't imagine any other satellites with the need to furl and unfurl the arrays repeatedly...

nathan.moeller · « **Reply #61 on:** 10/31/2007 05:26 am »

Let's not point fingers guys. Sometimes things don't go as planned and pieces can fall apart. We also have to remember that these arrays are almost four years older than they were when STS-119 had this task and was slated to fly in early 2004. It makes a big difference. Let's sit back and watch NASA and their friends work their magic. They've done an amazing job getting this complex assembled and working. I'm actually excited to see how they work this out. All the best to them all...

ckiki lwai · « **Reply #62 on:** 10/31/2007 09:32 am »

Could the P6 have been installed right after P5 was installed, without retracting the P6 solar arrays?
Or are the P6 solar arrays not strong enough to be moved or are there clearance problems?
If possible it would have saved us a lot of trouble.

Jim · « **Reply #63 on:** 10/31/2007 10:34 am »

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shuttlelegs - 30/10/2007 10:55 PM

Is this the end of line of such a solar array ? More rigid ones such as the ones which replaced the Hubbles solar arrays more likely to be used in the future if the need appears

No. this array is an advancement. Let's not throw the baby out with the bath water

Jim · « **Reply #64 on:** 10/31/2007 10:35 am »

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yoda - 30/10/2007 10:45 PM

If the two sides of the hinge could be aligned, maybe a wire or thin rod could be inserted to reattach the ripped or separated segment, like a long door pin. Could an EVA accomplish this?

Is it possible the solar array panels were misaligned when stowed for movement, then as the panels were pulled out accordian style, the hinge was caught on part of its stowage box, causing the rip?

There is no "hinge" it is a fold

Jim · « **Reply #65 on:** 10/31/2007 10:35 am »

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rdale - 30/10/2007 11:05 PM

I can't imagine any other satellites with the need to furl and unfurl the arrays repeatedly...

there are some

Jim · « **Reply #66 on:** 10/31/2007 10:37 am »

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ckiki lwai - 31/10/2007 6:32 AM

Could the P6 have been installed right after P5 was installed, without retracting the P6 solar arrays?
Or are the P6 solar arrays not strong enough to be moved or are there clearance problems?
If possible it would have saved us a lot of trouble.

they needed to be retracted for the move. Too unwieldy

jaredgalen · « **Reply #67 on:** 10/31/2007 11:26 am »

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Jim - 31/10/2007 12:35 PM
There is no "hinge" it is a fold

If it is just a fold then the eyelets for the guidewires, are they attached adhesively and not part of a hinge mechanism?

My first thought was that it was a fold and not a 'hinge' and that the wire had snagged, tugged and ripped along the fold like perforated paper.

But looking closer I keep wanting to call it a hinge!

brihath · « **Reply #68 on:** 10/31/2007 12:05 pm »

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rdale - 30/10/2007 11:05 PM

I can't imagine any other satellites with the need to furl and unfurl the arrays repeatedly...

I would imagine Keyhole satellites. They make significant orbital adjustments.

Jim · « **Reply #69 on:** 10/31/2007 01:57 pm »

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brihath - 31/10/2007 9:05 AM

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rdale - 30/10/2007 11:05 PM

I can't imagine any other satellites with the need to furl and unfurl the arrays repeatedly...

I would imagine Keyhole satellites. They make significant orbital adjustments.

Orbital adjustment is not a reason to retract an array. The ISS doesn't

brihath · « **Reply #70 on:** 10/31/2007 02:11 pm »

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Jim - 31/10/2007 10:57 AM

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brihath - 31/10/2007 9:05 AM

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rdale - 30/10/2007 11:05 PM

I can't imagine any other satellites with the need to furl and unfurl the arrays repeatedly...

I would imagine Keyhole satellites. They make significant orbital adjustments.

Orbital adjustment is not a reason to retract an array. The ISS doesn't

What are the reasons for retracting an array? You stated other satellites do.

Analyst · « **Reply #71 on:** 10/31/2007 03:37 pm »

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brihath - 31/10/2007 5:11 PM

What are the reasons for retracting an array? You stated other satellites do.

HST servicing: Solar array replacement.
Satellite retrieval by shuttle: Eureca and Japanese satellite in the mid 1990ies.

Analyst

rdale · « **Reply #72 on:** 10/31/2007 03:50 pm »

HST is already up there and there won't be any more satellite retrievements by the shuttle... So back to the original post - what future satellites will be affected by the array problems on ISS? My list remains pretty short :>

brihath · « **Reply #73 on:** 10/31/2007 03:57 pm »

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rdale - 31/10/2007 12:50 PM

HST is already up there and there won't be any more satellite retrievements by the shuttle... So back to the original post - what future satellites will be affected by the array problems on ISS? My list remains pretty short :>

My thoughts too. I was thinking in terms of operational systems, and treated Hubble as a special case, as it was designed for on orbit servicing. Forgot about Eureca...it was a while ago.

Jim · « **Reply #74 on:** 10/31/2007 04:28 pm »

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rdale - 31/10/2007 12:50 PM

HST is already up there and there won't be any more satellite retrievements by the shuttle... So back to the original post - what future satellites will be affected by the array problems on ISS? My list remains pretty short :>

No "NASA" spacecraft.

MILSTAR was a spacecraft that used these type arrays

Speedracer · « **Reply #75 on:** 10/31/2007 07:15 pm »

[[Someone moved this from the FD9 thread]]]

Also, if you want gloom & doom journalism, go pick up a copy of USA Today, and look at page 3.

spacedreams · « **Reply #76 on:** 10/31/2007 07:05 pm »

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ckiki lwai - 31/10/2007 3:32 AM Could the P6 have been installed right after P5 was installed, without retracting the P6 solar arrays? Or are the P6 solar arrays not strong enough to be moved or are there clearance problems? If possible it would have saved us a lot of trouble.

P6 installation could have and should have been done on 13A.1. It was originally planned that way

And to answer your other question, the retraction was required due to translational loads during relocation

Speedracer · « **Reply #77 on:** 10/31/2007 07:11 pm »

What if.... They could use the Station's Canadarm-2 to latch on to the shuttle, then maneuver it to the location via the CETA (sp?) cart, then the shuttle's arm might reach the affected area? I know there's space, room, maneuverability, etc. but still its a thought.

MKremer · « **Reply #78 on:** 10/31/2007 07:14 pm »

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Speedracer - 31/10/2007 3:11 PM

What if.... They could use the Station's Canadarm-2 to latch on to the shuttle, then maneuver it to the location via the CETA (sp?) cart, then the shuttle's arm might reach the affected area? I know there's space, room, maneuverability, etc. but still its a thought.

If they've already determined they couldn't translate with P6 on the SSRMS and had to do handoffs while moving the MT, there's no way anyone is going to suggest not only undocking the Shuttle (a non-starter to begin with without all the Shuttle crew onboard and the way the APAS docking system works), but then trying to move its 110 tons using the SSRMS and MT.

Speedracer · « **Reply #79 on:** 10/31/2007 07:19 pm »

There's always this stuff...

psloss · « **Reply #80 on:** 10/31/2007 07:19 pm »

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Speedracer - 31/10/2007 4:15 PM

What if....

They could use the Station's Canadarm-2 to latch on to the shuttle, then maneuver it to the location via the CETA (sp?) cart, then the shuttle's arm might reach the affected area? I know there's space, room, maneuverability, etc. but still its a thought.

In addition to MKremer's answer, if you could somehow get the orbiter out there, you now have that 110+ tons way out on the end of the truss -- has it been analyzed for putting that much mass out on that kind of moment-arm (work site

? What kind of loads would that put on all those parts (SSRMS, MT, SARJ)?

Ronsmytheiii · « **Reply #81 on:** 10/31/2007 08:05 pm »

With the OBSS being used for the station repair, my thoughts are why not leave a SBSS (Station Boom Sensor system) on the last flight to the ISS? By the last flight, one of the shuttles will be retired with another as a backup besides the primary, so on of the OBSS can be rebuilt. The only problems I see are the sensors being damaged (I am sure that we could have a removable version with some modifications) and also a storage placement. however, I think that STS-120 has proved that it is a valid option to have.

Edit: Whoo hoo, number 100! Put the serious face back on...

nathan.moeller · « **Reply #82 on:** 10/31/2007 08:14 pm »

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Ronsmytheiii - 31/10/2007 4:05 PM

With the OBSS being used for the station repair, my thoughts are why not leave a SBSS (Station Boom Sensor system) on the last flight to the ISS? By the last flight, one of the shuttles will be retired with another as a backup besides the primary, so on of the OBSS can be rebuilt. The only problems I see are the sensors being damaged (I am sure that we could have a removable version with some modifications) and also a storage placement. however, I think that STS-120 has proved that it is a valid option to have.

Edit: Whoo hoo, number 100! Put the serious face back on...

No need for an actual sensor system boom for the station. A boom by itself maybe. But the 'sensor system' in OBSS means just that. It's for sensing the RCC panels. Station doesn't need to 'sense' anything. It could be practical as a repair platform, though.

kevwalsh · « **Reply #83 on:** 10/31/2007 09:55 pm »

One of the fun parts of keeping something in space for long duration is coming to grips with fixing the inevitable problems in situ... viz Skylab, Salyut 7, Mir... and much better to learn how to cope with these kinds of problems in LEO than in LMO ;-)

MKremer · « **Reply #84 on:** 10/31/2007 10:11 pm »

I sure will be interested to hear or read some details about where the parts and pieces used for constructing the new load straps will be coming from.

Norm Hartnett · « **Reply #85 on:** 10/31/2007 10:30 pm »

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MKremer - 31/10/2007 4:11 PM

I sure will be interested to hear or read some details about where the parts and pieces used for constructing the new load straps will be coming from.

Wait for the movie, they will show it in gory engineering detail, A'la Apollo 13.

Ronsmytheiii · « **Reply #86 on:** 10/31/2007 10:34 pm »

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nathan.moeller - 31/10/2007 5:14 PM

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Ronsmytheiii - 31/10/2007 4:05 PM

With the OBSS being used for the station repair, my thoughts are why not leave a SBSS (Station Boom Sensor system) on the last flight to the ISS? By the last flight, one of the shuttles will be retired with another as a backup besides the primary, so on of the OBSS can be rebuilt. The only problems I see are the sensors being damaged (I am sure that we could have a removable version with some modifications) and also a storage placement. however, I think that STS-120 has proved that it is a valid option to have.

Edit: Whoo hoo, number 100! Put the serious face back on...

No need for an actual sensor system boom for the station. A boom by itself maybe. But the 'sensor system' in OBSS means just that. It's for sensing the RCC panels. Station doesn't need to 'sense' anything. It could be practical as a repair platform, though.

The Sensor system would be fantastic for a spektyr scenario, with a hole that cannot be found. If anything happened to a module, they could just scan it to locate the hole and then plug it up. Also, having a lidar and laser camera in space is never a bad idea.

MKremer · « **Reply #87 on:** 10/31/2007 10:59 pm »

A "hole that can't be found" is rather farfetched, especially as a pressure vessel leak needs to be patched from the inside, and wouldn't necessarily correspond to an outer MMOD shield impact location (that is, once you manage to find one).

In other words, if a leak of any type occurs, you don't immediately jump on the SSRMS controls to start looking for outside holes - you find and stop the internal leak ASAP, or close off the affected module, or abandon the station as a last resort, depending on severity.

After a leak is stopped (and assuming it's due to a MMOD hit) it doesn't mean diddly about where an outer hole might be unless you're making the time and resources available to find it strictly for scientific and engineering research data purposes.

ckiki lwai · « **Reply #88 on:** 11/01/2007 10:33 am »

While talking about combining arms, could they combine the European robotic arm with the SSRMS?
It would be an extension of 10m (33 feet), and even if doesn't fit with the SSRMS, they could build a small coupling system.
It could be very useful if they need to reach some of these far spots again.

Jim · « **Reply #89 on:** 11/01/2007 10:41 am »

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ckiki lwai - 1/11/2007 7:33 AM

While talking about combining arms, could they combine the European robotic arm with the SSRMS?
It would be an extension of 10m (33 feet), and even if doesn't fit with the SSRMS, they could build a small coupling system.
It could be very useful if they need to reach some of these far spots again.

The OBSS has no joints and therefore no control is needed. The ERA wouldn't work, it needs power and data

ckiki lwai · « **Reply #90 on:** 11/01/2007 10:59 am »

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Jim - 1/11/2007 12:41 PM

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ckiki lwai - 1/11/2007 7:33 AM

While talking about combining arms, could they combine the European robotic arm with the SSRMS?
It would be an extension of 10m (33 feet), and even if doesn't fit with the SSRMS, they could build a small coupling system.
It could be very useful if they need to reach some of these far spots again.

The OBSS has no joints and therefore no control is needed. The ERA wouldn't work, it needs power and data

And would it be possible to fix the joints of the ERA so they can't turn and then place it on the SSRMS, and free the joints when it is placed back on the Russian part?

Jim · « **Reply #91 on:** 11/01/2007 11:25 am »

just leave it. It is not viable. The ERA is only on the russian segment. How would the SSRMS grab it while it is straight and still attached at the base. They were never meant to work together.

Power is needed to couple. How would the ERA couple the "adapter"?

Ronsmytheiii · « **Reply #92 on:** 11/01/2007 01:33 pm »

Sorry to stay off topic, promise to get back after this. However, will the European arm replace or supplement the STRELA crane already on the Russian segment?

Lee Jay · « **Reply #93 on:** 11/01/2007 01:42 pm »

Would DEXTRE have alleviated this problem, or is it (he?) just too short?

Jim · « **Reply #94 on:** 11/01/2007 01:44 pm »

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Lee Jay - 1/11/2007 10:42 AM

Would DEXTRE have alleviated this problem, or is it (he?) just too short?

too short

bobthemonkey · « **Reply #95 on:** 11/01/2007 01:44 pm »

Dextre would only work with compatible couplings. Think of it as a very large EVA PGT. It doesn't add much length at all to the SSRMS.

Iren · « **Reply #96 on:** 11/01/2007 08:00 pm »

Hello there, first post

I've been asking me something about the so-called power shortage for Columbus and Kibo... ISS was going to have 2 now-cancelled modules (Hab module and Centrifuge module), powering the whole station with the 4 solar array pairs, so why is there a power shortage if the ISS isnt going to have those modules?

Hope someone understands my question. Sorry for spelling, english is not my mother lang

Jim · « **Reply #97 on:** 11/01/2007 08:04 pm »

The Russian SPP was canceled so the US has to provide the Russian segment with some power. Most of the HAB systems are now distributed through out the ISS.

Iren · « **Reply #98 on:** 11/01/2007 08:08 pm »

Thanks, I though that the russian segment, in the current configuration, could get the power they needed by itself... Then why Zarya's solar panels are retracted?

swhitt · « **Reply #99 on:** 11/01/2007 08:09 pm »

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Iren - 1/11/2007 2:00 PM

Hello there, first post

I've been asking me something about the so-called power shortage for Columbus and Kibo... ISS was going to have 2 now-cancelled modules (Hab module and Centrifuge module), powering the whole station with the 4 solar array pairs, so why is there a power shortage if the ISS isnt going to have those modules?

Hope someone understands my question. Sorry for spelling, english is not my mother lang

Iren, welcome to the forum.

The reason for the power shortage is that the Russian Segment was originally designed to have a large solar array as well. But due to reconfigurations, they are now going to use the main array. So the trade was to not consume electricity for the two modules you mention and allow the Russian Segment to consume more.

This equalled out. So if the main array is not a full strength, there is a shortage.

JesseD · « **Reply #100 on:** 11/01/2007 08:25 pm »

The array is still running at 97% nominal production. (as per MMT conference yesterday) The problem is that with the tear, they can't put the normal 75 lbs tension on the array to stabilize and lock it. hopefully the 'cufflink' fix will work!!

Jorge · « **Reply #101 on:** 11/01/2007 08:25 pm »

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Iren - 1/11/2007 4:08 PM

Thanks, I though that the russian segment, in the current configuration, could get the power they needed by itself... Then why Zarya's solar panels are retracted?

To provide clearance for the rotation of the S1 and P1 radiators.

rocketguy101 · « **Reply #102 on:** 11/02/2007 12:53 pm »

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Chandonn - 2/11/2007 7:53 AM I would like to interject one observation about ISS from this flight. As some of you know, I'm one of those crazy people who updates his ISS model as the real ISS updates on orbit. On this flight, when P6 moved, it became VERY apparent how much ISS now dwarfs the shuttle. When Discovery undocks and does the fly-around, the shear size of ISS should be much more impressive than on previous flights.

Would it be appropriate for you to post a photo of your model in this thread? It might help some of us to visualize where everything is in relation to the shuttle, etc. I know this is for FD activities and updates, but it is hard for alot of us not intimately familar w/ ISS to grasp the size and location of everything, and we won't see the big picture until undock!!

dmgaba · « **Reply #103 on:** 11/02/2007 12:59 pm »

I'm curious about the expected life-time of the SAW repair. What analysis has been done about thermal cycling, sun exposure, etc. of the "cuff link" & wire fix? That is, will it someday be necessary to install more per permanent load-carrying devices in place of the parts to be installed tomorrow?

Mike_1179 · « **Reply #104 on:** 11/02/2007 02:52 pm »

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dmgaba - 2/11/2007 9:59 AM

I'm curious about the expected life-time of the SAW repair. What analysis has been done about thermal cycling, sun exposure, etc. of the "cuff link" & wire fix? That is, will it someday be necessary to install more per permanent load-carrying devices in place of the parts to be installed tomorrow?

The SAWs are designed for orbital replacement. From what I understand, spare blanket boxes can be sent up on a later shuttle flight and stowed on one of the ESPs for installation after the shuttle is retired. There's still the matter of jettisoning the current array, but that's another problem...

One problem is there are no spare blankets built yet. The only "replacement" could be the 4A array packed up and ready to go on the S6 truss later next year. The vendor would have to make up a new one and it would need a ride uphill somewhere in the future.

ehartwell · « **Reply #105 on:** 11/02/2007 02:56 pm »

MacGyver challenge: Fix a space station using Sharpie, Ziplock bag, camera, vacuum cleaner, scraps (duct tape allowed).

The winning entry is covered in exquisite detail at collectSPACE,
http://www.collectspace.com/news/news-110207a.html

http://www.collectspace.com/images/news-110207a.jpg" align="right">"How exactly does one assemble a space station saving cufflink from spare parts? Very carefully, as appears to be the case in this, the seven-part instructions that were uplinked to the astronauts, complete with illustrations for key steps. Warning: it's acronym laden (e.g. FOD=foreign object debris, MCC-H=Mission Control Center-Houston) and with the possible exception of the ink marker and two ziplock bags, calls for items not usually found around the house, so it's probably best kids, not to try this at home."

Zero-G · « **Reply #106 on:** 11/02/2007 04:20 pm »

There seem to be big concerns about the risk of an electric shock to the astronaut who will work on the SAW in order to fix it. The electrical tension in the SAW is 110 volts, is this right? How many amps does the SAW produce normally? I understand that the electrical power in the SAW cannot be switched off, because, by design, the array starts to generate electricity as soon as it is deployed (that's what it's there for, after all). So, here is my question: Would it not be possible to significantly reduce electrical power generation, maybe even below a safe level, by turning the SAW into a position where either the "backside" of the photovoltaic cells or the small edge of the SAW faces the sun, in order to avoid sunlight hitting the photovoltaic cells? If not, why?

(I am new to this forum and I hope this question has not been answered elsewhere.)

rdale · « **Reply #107 on:** 11/02/2007 04:27 pm »

It's not really a concern - everything they've done in planning and toolmaking will insure that won't happen.

But even if it was a real risk, remember the ISS is orbiting. It's always moving with respect to the sun, so the SAW would be swinging around a lot. That makes the repair VERY difficult, because the SSRMS can't swing around in tandem.

So with electrocution not a concern, and no way to stop the sun :>, there's no need to turn the SAW.

jeklund · « **Reply #108 on:** 11/02/2007 04:30 pm »

It sounds to me from what I have heard that they think they have the elecricity risk mitigated or understood pretty well, and don't think they need to do anything else. They do, however need to keep the array in a position that will allow access, and provideplenty of sun for the OBSS sensors. Dave Wolf sounds like it's not a big worry for him.

Speedracer · « **Reply #109 on:** 11/02/2007 05:48 pm »

Not sure about this, but if they are concerned with Scott getting zapped by juice from the array, then would it not be feasible for him to do the close-contact work during a night pass? While I'm sure lighting is an issue, the lighting from his helmet should supply enough to work in the area, and the low emission of light from his helmet should be negligible regarding shock potential.

rdale · « **Reply #110 on:** 11/02/2007 05:52 pm »

Once again - they aren't concerned about him getting zapped.

In any case, lightning is an issue.

1) He needs to see what he's working on, and what impact(s) it might have downstream.
2) EV2 needs to see him
3) ROBO & EV2 need to see clearances of the arm.

Once again - everything they are doing negates the risk of shock. There's no need to wait for night, and waiting for night is not helpful due to other reasons.

Mike_1179 · « **Reply #111 on:** 11/02/2007 05:57 pm »

I think everyone is so bent by the "electrocution hazard" because this is something that we can all understand and deal with here on the ground. The risks for MMOD on their suits are always there when you step outside the hatch, but no one really talks about those because at home you never have to think about your clothes being pierced by something traveling at 12,500 mph.

It's not that much larger of a risk than much of the other risky things here, it just seems that way because we have a risk of electrocution in our homes

Speedracer · « **Reply #112 on:** 11/02/2007 06:05 pm »

Zero-G · « **Reply #113 on:** 11/02/2007 06:06 pm »

Thanks for the replies. I do understand the SAW cannot swing around a lot during the repair and needs to be stable in an accessible position, but what I meant was a position which points the small edges of the SAW to the sun (instead of the full breadth) for most of the time during orbit, thus reducing power generation significantly. Or the array could be turned in a way that the cells face to earth most of the time. But, if electric shock is not a concern anymore this may not be necessary anyway.
I know the crew would need as much light as possible to see what they are doing, but why would "plenty of sun for the OBSS sensors" be needed for the SAW repair? I thought they would use the OBSS boom just as a working platform with a foothold, to expand the SSRMS' reach in order to get access to the damaged area. The sensors themselves would not be needed for this task, would they? Besides, the work area (and the sensors) would be in the dark every 45 minutes anyway.

Mike_1179 · « **Reply #114 on:** 11/02/2007 06:15 pm »

If the sensors get too cold, they may break. If they break, they can't be used to inspect the orbiter during the late inspection for MMOD after undocking.

Also, the beta angle is still pretty high, so they will be in sunlight for much more than half an orbit

chksix · « **Reply #115 on:** 11/03/2007 07:53 am »

I hope they are developing an extension for the SSRMS that can be housed on ISS permanently. The need to reach further with the station arm may occur in the future also.

Avron · « **Reply #116 on:** 11/03/2007 07:23 pm »

who said - "And Houston, just so you know, it was only one strand that was popped"..

I think we have a very high res pic of that "popped" strand coming down soon.. followed a few days by the actual strand..

(no idea what this is about. All is in the live flight day 13 thread. This thread is defunct now, so locking - James).