Where does the Kibo RMS Fit?

[Mark Nguyen]

I was led to believe that Kibo's robot arm, launching with the big pressurized module on this flight, was going to be tucked in where the OBSS would normally be kept - thus explaining why they're leaving the OBSS at the station on STS-123. But pictures of Kibo in the processing building show the arm tucked in the back of the module, where it's already installed! Does anyone know where the arm will be in launch position, and if it's not opposite the shuttle RMS, why *are* there clearance problems anyway? Isn't the main Kibo module the same diameter as all the other modules?

Mark

[DaveS]

It has to do with the RMS grapple fixture. Not sure if it is a FRGF or a PDGF but it would cause a potrusion towards the where the OBSS would be and given that there's no space in the payload bay for a sidewall carrier, only option is to leave OBSS at station during STS-123/1JA and pick it up during STS-124/1J.

[Analyst]

Mark Nguyen - 12/3/2008  6:18 PM

1) Does anyone know where the arm will be in launch position,
2) and if it's not opposite the shuttle RMS, why *are* there clearance problems anyway?
3) Isn't the main Kibo module the same diameter as all the other modules?

Mark

1) It will be exactly where it is in the photos: front of Kibo, facing forward in the payload bay.
2) For Columbus and the Kibo logistics module the clearance problems were PDGF or FRGF, e.g. SSRMS, SRMS grapple fixtures. For Columbus they installed it during an EVA, for the Kibo logistics module were are two redundant grapple fixtures and they removed the redundant one. I don't know which structure part causes the clearing problem for Kibo.
3) Yes.

Analyst

[Analyst]

DaveS - 12/3/2008  6:25 PM

... and given that there's no space in the payload bay for a sidewall carrier ...

Really? There is space forward in the payload bay of STS-124.

Analyst

[DaveS]

Analyst - 12/3/2008  5:29 PM

DaveS - 12/3/2008  6:25 PM

... and given that there's no space in the payload bay for a sidewall carrier ...

Really? There is space forward in the payload bay of STS-124.

Analyst

How much? A sidewall carrier uses up one bay of the payload bay which consists of 13 bays.

[Analyst]

Enough. At least 4 bays, which is enough for the ODS and a sidewall carrier. Kibo is about 11m long, maybe 12m with its RMS.

Btw. you could mount a PDGF taken from another module during an EVA or one launched on a different flight. There has to be another clearance issue than a PDGF. I guess I read something about it in the Mini OBSS boom thread.

Analyst

[Gary]

Analyst - 12/3/2008  5:29 PM

DaveS - 12/3/2008  6:25 PM

... and given that there's no space in the payload bay for a sidewall carrier ...

Really? There is space forward in the payload bay of STS-124.

Analyst

Doesn't STS-124 suffer with some weight issues though? It might be that there is enough space but there isn't the weight margin.

[Analyst]

No, not to this degree.

Analyst

[DaveS]

Analyst - 12/3/2008  6:14 PM
There has to be another clearance issue than a PDGF.

Maybe, but's it's a reason. That's why they removed Columbus PDGF during prelaunch processing and stuck it on a sidewall carrier and had to be EVA installed.

[uko]

My guess is that the Kibo PDGF was designed this way that it can not be removed and reinstalled. So that's why it has to stay and OBSS had to go.

[The-Hammer]

uko - 12/3/2008  1:23 PM

My guess is that the Kibo PDGF was designed this way that it can not be removed and reinstalled. So that's why it has to stay and OBSS had to go.

The PDGF is an ORU. In order to replace, one must be able to remove and reinstall.