Question about Node 3

[PJay_A]

Looking at the latest Wikipedia illustriation of the ISS configuration, it appears that not all of Node 3's ports would be usuable. It looks like the truss structure gives very little clearence for one of the ports and the port on the opposite side may have clearence issues as a result of the location of the Kibo modules. Clearance on the Kibo side may not be an issue if whatever may attach there is short in size, but I see no space (or little space) on the truss side for anything.

With President Obama's new NASA mandate calling for ISS' life extension beyond 2020, station expansion beyond the 2011 "Construction Complete" configuration is not "out of the question" any more. As such, all the station's ports need to be clear and ready for any future prospects for expansion. One such proposal, made by British scientists last year, would add two small habition modules built and paid for by the UK. These modules were proposed as atachments to Node 3, but under a previous configuration plan for Node 3 (with no clearance issues). Now that ISS is getting a life extension, the UK government would get their money's worth in years of utilization of these two proposed modules if the project gets funding and parlimentary approval.

As a side note, last year Russia announced expansion on their side of the station will continue after next year's launch of the last module (officially on the ISS manifest) Nauka (Multipurpose Laboratory Module). The plan includes 3 additional modules: a Russian Node ("Nodal") Module and two science modules. The science modules will also provide additional solar arrays to power the Russian side of the station for when NASA's power obligations to Russia expires.

Here's links to the proposed expansion projects:

British Hab Modules

Russian Side After Expansion

Russian Node Module Details
http://www.russianspaceweb.com/iss_node.html

Official Russian-Side Expansion Proposal to NASA
http://www.nasa.gov/pdf/361832main_05 - Presentation_Engl.pdf

British Hab Modules Details
http://en.wikipedia.org/wiki/Habitation_Extension_Module

 

[Zipi]

If Trainquility is placed to earth facing port of Unity there will be clearance issue with MRM-1 module. So current configuration is probably as good as the earlier. I also speculate that current configuration is better for atmospheric drag wise and offers less surface for micrometeoroids to hit the station.

With current configuration there is Harmony's eath facing port and space facing port available as well as Unity's earth facing port. Tranquility's forward and backward ports with current configuration are also available to some purposes if needed. Permanent logistics module will probably be installed to Unity's earth facing port. Even if there are HTV and Dragon docked at the same time to the space station there still is Tranquility's forward and backward ports available. So I'm pretty sure this is enough if somebody wants to expand the spacestation.

And I somebody wants to expand the station then those new modules should already be in production in a year or two... Otherways it will take too long until the new modules are delivered to the station, which basically mean that there will not be any new modules. Russians might do new modules if they got money since they have said they want to keep their part of ISS flying even "the international" part is being deorbited. But it will be a some sort of miracle if they got the money...



ISS @ Wikipedia: http://en.wikipedia.org/wiki/Internatio ... ce_Station

 

[Zipi]

Actually it might be possible that Tranquility's space facing port is available with current configuration... Scroll this video to 4min 18sec:

[youtube]http://www.youtube.com/watch?v=1nk3QB3g7dk[/youtube]

If its top port is available then this current configuration is better than originally planned at Unity's earth facing port. If somebody knows this for sure, please give the facts!

Above video also shows also that there is plenty of room for modules to berth Tranquility's forward and backward ports.

EDIT: Also look this picture how the Z1 is attached Unity's top port and the struss it attached to the front side of Z1:

So at least it should be possible to make a custom module which can be attached to the top port of Tranquility if "normal" modules won't fit. Meaning the CBM mechanism would be on the outer edge of the special module instead of center like all "normal" modules have. Or the special module could have smaller diameter or some sort of dent to avoid the struss... For me it now seems that there are at least possibility to use the top port of Tranquility.

 

[Zipi]

I just heard and got "proof" that the struss is not attached to Z1, but on the top of Destiny:



So perhaps there is even more clearance available for Tranquility's space facing port usage... But let's see, since I really want to dig this information out from somewhere.

EDIT: I got more information about this and it seems that there is robotic arm PDGF (Power Data Grapple Fixture) hardware blocking the usage of that port. Also it don't have the latching mechanism installed since it was not intended to be used in the original configuration. So basicly the zenith port of Tranquility is only CBM look-a-like, but not a real docking port.

 

[CalliArcale]

EDIT: I got more information about this and it seems that there is robotic arm PDGF (Power Data Grapple Fixture) hardware blocking the usage of that port. Also it don't have the latching mechanism installed since it was not intended to be used in the original configuration. So basicly the zenith port of Tranquility is only CBM look-a-like, but not a real docking port.

Correct. The hull is identical to the other Nodes, but they didn't put in all of the hardware for making all of the ports into fully functioning CBMs. Basically, once it was decided to stop at this "core complete" configuration, they saw those ports as a way to save a little bit of money. Can't say I blame them, but it does limit the options for using Tranquility in the future. At least they did put it up there, so it's good for something instead of just being shoved into a museum on Earth. That was the fate of the CRV, after all. (And Skylab 2. Congress has a bit of a habit of canceling things which are fairly close to completion.)

 

[Gravity_Ray]

I think at this point Node 3 is done. I doubt very much any of its open ports can be used even if they were fully functioning CBM's. From all the pictures that Zipi posted I don’t see anything that can be attached to it. Even the end port is not really useful, although the truss is not directly above it, the rotating solar panels, and the radiators are going to be in the way of anything coming in to dock to it.

It’s a room with a view now.

 

[tadpoletriker]

It seems that after the Permanent Logistics Module is installed there will be two functional CBMs, and perhaps two more when the Shuttles are retires, and the PMAs are no longer of use and could be discarded?

JohnB

 

[PJay_A]

It seems that after the Permanent Logistics Module is installed there will be two functional CBMs, and perhaps two more when the Shuttles are retires, and the PMAs are no longer of use and could be discarded?

JohnB

Are the PMAs attached to active or passive CBMs? If those CBMs are passive, then they're as good as useless, unless some nation is willing to front the expensive of constructing an ACBM port onto a new module (like was donw with Destiny and the Kibo lab module).

 

[Zipi]

PMA-2 will be at the front port of Harmony as long as there is some other docking adapter to berth in that port. Axial ports of Node-2 and Node-3 don't have possibility to attach thermal and MMOD covers like the ports around them. If there is open axial port at Node-2 or Node-3 it will need a spacewalk to attach some shielding and the same thing to remove it if that port is needed. That is why they will keep PMA-2 at Node-2 front port until some other docking adapter is available and needed.

Tranquility's (node-3) forward and backward ports are available and usable. They can for example locate PMA-2 to backward port of Node-3 for stowage space when it has to be removed from Node-2. The forward port of Node-3 can host a normal space station module as far as I can see and I think there is enough space for norman module at Node-3 backward port even the radiators are near.

 

[PJay_A]

Could they just relocate Node 3 (if they need to) in the future to the forward port of Node 2?

 

[Zipi]

Could they just relocate Node 3 (if they need to) in the future to the forward port of Node 2?

I quess they could do that if needed. However I don't have 100% sure information about this. If they do such move I think they keep Node-3's current orientation as it currently is, meaning the non-functioning CBM at the top.

Only thing which I can imagine to prevent this are the cooling lines, but those can probably be adjusted by launching needed parts up.

 

[Zipi]

I had to copy & paste erioladastra's comment from NASA Spaceflight's forums conserning re-enabling Tranquility's top CBM:

Actually, we have looked at it and every component could be installed on orbit. Not easy is not the same as not possible. Three years ago moving Node 3 to port (and last year moving it back to nadir after activation on port) was 'not possible'. All the changes we have made have had the rule that it has to be "reversable".

True in the sense of that is the current state and plans. However, if the program really wanted to do it, the PDGF can be removed and the CBM mechanisms installed. Would be a pain but could be done.

Original post: http://forum.nasaspaceflight.com/index. ... #msg549055

 

[Zipi]

Nice view directly under ISS: