Author Topic: General ISS Q&A thread  (Read 659007 times)

Offline Danderman

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Re: General ISS Q&A thread
« Reply #1480 on: 06/28/2010 03:02 PM »
my question is, could the Russians move these panels

That is the issue.  They aren't designed for it.

Although I don't know if the FGB panels are removable, certainly earlier FGB class spacecraft featured removable solar panels. The Kristal module's panels were removed for clearance issues with Shuttle dockings, and were translated to the Kvant module on Mir.

Offline orbiter62995

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Re: General ISS Q&A thread
« Reply #1481 on: 07/17/2010 04:08 PM »
Another question:

Concerning the US solar wings and their truss segments, do the open ends of the (assembled) truss have "hooks" that could allow for an extension on either side for assembly of additional US-supplied panels?

This is just a hypothetical question. Nevermind the fact that these can only be carried up by shuttle and that additional power is not required at this time, but suppose a future COTS contract makes this possible and future (as of now unplanned) expansion modules require additional power.
The S6 and P6 Trusses do not have any attachment mechanisms to add additional Truss segments (nor did the P3/P4 or S3/S4 Trusses – the P5/S5 Trusses had to be added to allow the P6/S6 Trusses to be attached).

Not true.  There isn't anything to  on the end of P6/S6 to attach another  P5/S5 type trusses

It's almost impossible.  The only way I see this being done is if the SSRMS grappled the entire stack of Truss modules (P3-P6 or S3-S6) and moved them somewhere else while another spacer or solar array module was added.  This is virtually impossible though as it takes at least two robotic arms to move Truss components into place, let alone that Canadarm2 can only lift 60 tons at a time.  Also, the P3 and P4 and S3 and S4 are inseparable and therefore you'd have these new modules opposite the SARJ.


Now, a quick question…what's the difference between a PVGF and an FRGF?
« Last Edit: 07/17/2010 11:48 PM by orbiter62995 »
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Re: General ISS Q&A thread
« Reply #1482 on: 07/18/2010 04:00 AM »
A PVGF - Power and Video Grapple Fixture, allows the SSRMS to provide power to the grappled payload, and receive a video signal back from it (for berthing purposes). It can be found on ESP-3, ICC-VLD, ELC-1, ELC-2, Node 3 Zenith (Where the Zenith CBM used to be) and possibly other places I don't recall offhand.

A FRGF - Flight Releasable Grapple Fixture, is just the grapple fixture, no power, no video, no data. It can be found on the PMAs, MPLMs, the mid-point of the OBSS, and possibly other places I don't recall offhand.
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Offline orbiter62995

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Re: General ISS Q&A thread
« Reply #1483 on: 07/18/2010 12:36 PM »
A PVGF - Power and Video Grapple Fixture, allows the SSRMS to provide power to the grappled payload, and receive a video signal back from it (for berthing purposes). It can be found on ESP-3, ICC-VLD, ELC-1, ELC-2, Node 3 Zenith (Where the Zenith CBM used to be) and possibly other places I don't recall offhand.

A FRGF - Flight Releasable Grapple Fixture, is just the grapple fixture, no power, no video, no data. It can be found on the PMAs, MPLMs, the mid-point of the OBSS, and possibly other places I don't recall offhand.

Ah, meaning that the SSRMS can provide thermal control/electrical power need be to the payload via a PVGF?  That means then that modules with a PVGF would have a berthing mechanism built-in, though, correct?

(My 100th post)
« Last Edit: 07/18/2010 12:37 PM by orbiter62995 »
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Offline Space Pete

Re: General ISS Q&A thread
« Reply #1484 on: 07/18/2010 01:49 PM »
A PVGF - Power and Video Grapple Fixture, allows the SSRMS to provide power to the grappled payload, and receive a video signal back from it (for berthing purposes). It can be found on ESP-3, ICC-VLD, ELC-1, ELC-2, Node 3 Zenith (Where the Zenith CBM used to be) and possibly other places I don't recall offhand.

A FRGF - Flight Releasable Grapple Fixture, is just the grapple fixture, no power, no video, no data. It can be found on the PMAs, MPLMs, the mid-point of the OBSS, and possibly other places I don't recall offhand.

Ah, meaning that the SSRMS can provide thermal control/electrical power need be to the payload via a PVGF?  That means then that modules with a PVGF would have a berthing mechanism built-in, though, correct?

(My 100th post)

During STS-132, the SSRMS was able to receive video from and provide power to plus have command & control of MRM-1 via its PVGF.
PDGFs provide command & control capability of the SSRMS, and so are only used on modules where the SSRMS is going to be based.

(Ooh, just noticed, my 1001th post!) :D
« Last Edit: 07/18/2010 01:50 PM by Space Pete »
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Re: General ISS Q&A thread
« Reply #1485 on: 07/28/2010 08:30 AM »
Now that Poisk is at the station, why can't it be used as a backup airlock instead of the Pkoh/Zvesda docking node? 

Offline anik

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Re: General ISS Q&A thread
« Reply #1486 on: 07/28/2010 08:59 PM »
Now that Poisk is at the station, why can't it be used as a backup airlock instead of the Pkoh/Zvesda docking node?

Poisk module has Soyuz spacecraft on its zenith port. So if we will use Poisk as backup airlock, then we should have crew inside Soyuz. What to do if Poisk can not be repressurized? Especially in case one extravehicular cosmonaut belongs to one Soyuz crew, and other extravehicular cosmonaut belongs to another Soyuz crew. Do we need such difficulties with depressurizations of orbital module of Soyuz, which is docked to Poisk, and depressurization of the transfer compartment of Zvezda module? What is the problem with using of the transfer compartment as backup airlock? In my opinion, this variant of providing of safety is less difficult than others.

Offline Zero-G

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Re: General ISS Q&A thread
« Reply #1487 on: 07/28/2010 11:30 PM »
During the most recent station spacewalk (Russian EVA-25), the cosmonauts literally threw away an old video camera, by jettisoning it.
I assume that some certain parameters regarding direction, angle, speed, etc. in relation to the ISS need to be met, when jettisoning trashed equipment from the station, to make sure its orbit degrades and it burns up as soon as possible.
What are these parameters approximately?
Was the camera really thrown by hand, or was some device used?
What was the actual angle, speed, and direction imparted on the camera, in relation to the ISS? (I assume it was jettisoned "backwards", i.e. in the -x direction, with some downward angle)
When is the camera expected to approximately deorbit and burn up with the achieved orbital parameters?
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Offline Space Pete

Re: General ISS Q&A thread
« Reply #1488 on: 07/28/2010 11:37 PM »
During the most recent station spacewalk (Russian EVA-25), the cosmonauts literally threw away an old video camera, by jettisoning it.
I assume that some certain parameters regarding direction, angle, speed, etc. in relation to the ISS need to be met, when jettisoning trashed equipment from the station, to make sure its orbit degrades and it burns up as soon as possible.
What are these parameters approximately?
Was the camera really thrown by hand, or was some device used?
What was the actual angle, speed, and direction imparted on the camera, in relation to the ISS? (I assume it was jettisoned "backwards", i.e. in the -x direction, with some downward angle)
When is the camera expected to approximately deorbit and burn up with the achieved orbital parameters?

Objects are generally always jettisoned negative to the ISS's velocity vector. That way, the object's speed will be reduced and it will drop into a lower orbit. The object will then overtake the ISS due to the fact that it is in a lower orbit, and so it will not pose a debris threat to the ISS. I don't know what Delta-V of the jettison was, but it would be interesting to know.
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Offline Fuji

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Re: General ISS Q&A thread
« Reply #1489 on: 07/28/2010 11:56 PM »
When is the camera expected to approximately deorbit and burn up with the achieved orbital parameters?

NASA TV said approximately 120 days.

Offline erioladastra

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Re: General ISS Q&A thread
« Reply #1490 on: 07/29/2010 08:39 AM »
During the most recent station spacewalk (Russian EVA-25), the cosmonauts literally threw away an old video camera, by jettisoning it.
I assume that some certain parameters regarding direction, angle, speed, etc. in relation to the ISS need to be met, when jettisoning trashed equipment from the station, to make sure its orbit degrades and it burns up as soon as possible.
What are these parameters approximately?
Was the camera really thrown by hand, or was some device used?
What was the actual angle, speed, and direction imparted on the camera, in relation to the ISS? (I assume it was jettisoned "backwards", i.e. in the -x direction, with some downward angle)
When is the camera expected to approximately deorbit and burn up with the achieved orbital parameters?

Objects are generally always jettisoned negative to the ISS's velocity vector. That way, the object's speed will be reduced and it will drop into a lower orbit. The object will then overtake the ISS due to the fact that it is in a lower orbit, and so it will not pose a debris threat to the ISS. I don't know what Delta-V of the jettison was, but it would be interesting to know.

Requirement is min 5 cm/s purely retro.

Online Hungry4info3

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Re: General ISS Q&A thread
« Reply #1491 on: 08/01/2010 07:37 PM »
Just out of curiosity, and purely hypothetically speaking, what happen if ISS loses both A and B cooling systems?

Could they shut everything down and repair on orbit?

Offline rdale

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Re: General ISS Q&A thread
« Reply #1492 on: 08/01/2010 10:21 PM »
Hungry - no.

I am advised that the current failure is one of the "Big Fourteen" -- the most serious contingencies which leave the ISS no-fault-tolerant in other areas. It would imply quick evacuation of at least half the crew.

That was mentioned on L2 this morning... I can't find a list of those "14" anywhere online - any help?

Offline Harlan

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Re: General ISS Q&A thread
« Reply #1493 on: 08/02/2010 01:20 AM »
A little more generally, I get the impression that the cooling system is one of the more temperamental system on the station, and that there have been more problems over the years than anticipated. Presumably because of moving parts and liquids, at various temperatures. Are there alternative technologies that could be used to increase the reliability of the cooling system? What should the next generation of space habitats (e.g., Bigelow) be thinking about with regards to cooling?

Offline psloss

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Re: General ISS Q&A thread
« Reply #1494 on: 08/02/2010 01:39 AM »
A little more generally, I get the impression that the cooling system is one of the more temperamental system on the station, and that there have been more problems over the years than anticipated. Presumably because of moving parts and liquids, at various temperatures. Are there alternative technologies that could be used to increase the reliability of the cooling system? What should the next generation of space habitats (e.g., Bigelow) be thinking about with regards to cooling?
Which other situations are you thinking of?  I believe this unplanned loop 'shutdown' is a first.

Offline IVANW

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Re: General ISS Q&A thread
« Reply #1495 on: 08/02/2010 02:35 PM »
HI

Could anyone help with the following:

I have read that de & re pressurisation takes place in the crew airlock rather than the equipment airlock on the ISS.

I was wondering if the pressure of the crew airlock was controlled from within the crew airlock or by someone else within the equipment airlock or another part of the ISS?

If it is controlled in the crew airlock are the pressure controls part of the EVA panel or on the hatch door?     

Many thanks 

Offline billshap

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Re: General ISS Q&A thread
« Reply #1496 on: 08/05/2010 12:02 AM »
Not quite sure where this question belongs. . .NASA TV showed video today from the NBL of a run-through of Friday's ISS EVA to deal with the coolant pump failure.  Today's EVA rehearsal crew was identified multiple times as Bobby Satcher and Rick Sturckow.  Satcher makes sense, but how did Rick Sturckow get this assignment?  He's a Shuttle CDR.  No CDR or PLT has ever made an EVA (not counting PLTs who made the switch to MS).  To my knowledge no CDR or PLT has even trained for EVA since the earliest days of the program.  There is nothing in Sturckow's background to indicate he's trained for EVA, or ISS ops.  There should be an abundance of experienced EVAers around JSC who seem better suited to this work.  Can anyone enlighten me?

Offline psloss

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Re: General ISS Q&A thread
« Reply #1497 on: 08/05/2010 12:41 AM »
No CDR or PLT has ever made an EVA (not counting PLTs who made the switch to MS).  To my knowledge no CDR or PLT has even trained for EVA since the earliest days of the program.
You're forgetting Ken Bowersox.
« Last Edit: 08/05/2010 12:44 AM by psloss »

Online DaveS

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Re: General ISS Q&A thread
« Reply #1498 on: 08/05/2010 01:25 AM »
No CDR or PLT has ever made an EVA (not counting PLTs who made the switch to MS).  To my knowledge no CDR or PLT has even trained for EVA since the earliest days of the program.
You're forgetting Ken Bowersox.

Well, that's slightly different, he was a ISS Expedition CDR and they along with the rest the Expedition crew members receive EVA training.

But in this case we have STS CDR with no specific ISS Expedition training performing an NBL EVA run. I guess that places him out-of-standard as there is plenty of other EVA qualified STS MS's and other astronauts than an STS CDR who most likely only has IV training.

The practice of training STS CDRs/PLTs ended with the completion of the OFTs and the crew expanded to more than two. The first two flown MS's with EVA training was Lenoir and Allen on STS-5.
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Offline MBK004

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Re: General ISS Q&A thread
« Reply #1499 on: 08/05/2010 01:41 AM »
No CDR or PLT has ever made an EVA (not counting PLTs who made the switch to MS).  To my knowledge no CDR or PLT has even trained for EVA since the earliest days of the program.
The entire STS-125 crew was EVA qualified in case of LON and STS-400. Scooter and Ray Jay were EVA qualified.