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Space Pete
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« Reply #1875 on: 04/07/2012 03:32 PM » |
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Some ISS power/solar array questions!
•Do the U.S. segment arrays now provide all the power, or are the Russian module ones still used?
•How much power in watts does each U.S. and Russian solar array/wing generate?
Although the SM arrays provide some power to the RS, it isn't enough, so the USOS does provide additional power to the RS via the ARCU (American-Russian Conversion Unit) on PMA-1, which converts standard USOS secondary power (124.5 VDC) to standard RS power (28 VDC). US SAWs produce between 31kW and 26kW of power, depending on their age. SM array power output is unknown to me.
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erioladastra
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« Reply #1876 on: 04/10/2012 06:29 PM » |
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Some ISS power/solar array questions!
•Do the U.S. segment arrays now provide all the power, or are the Russian module ones still used?
•How much power in watts does each U.S. and Russian solar array/wing generate?
Although the SM arrays provide some power to the RS, it isn't enough, so the USOS does provide additional power to the RS via the ARCU (American-Russian Conversion Unit) on PMA-1, which converts standard USOS secondary power (124.5 VDC) to standard RS power (28 VDC).
US SAWs produce between 31kW and 26kW of power, depending on their age. SM array power output is unknown to me.
As part of the agreement over not having the SPP, NASA agreed to provide most of the RS power.
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Nicolas PILLET
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« Reply #1877 on: 04/14/2012 04:27 PM » |
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I would like to clarify the capabilities of the different grapple fixtures used on USOS... | Name | Power | Data | Video | | PDGF | Yes | Yes | Yes | | EFGF | | | | | PVGF | No | No | Yes | | FRGF | No | No | No |
I don't understand what is an EFGF. Also, I don't understand the usefulness of transmitting a video signal between SSRMS and its payload... Thanks for clarifications !
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Nicolas PILLET
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« Reply #1878 on: 04/14/2012 05:19 PM » |
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Found in the ISS Familiarization Manual : The RWS has components which are either external or internal to the rack. The external components, illustrated in Figure 8-6, are portable and include three video monitors, a Translational Hand Controller (THC) and a Rotational Hand Controller (RHC), a Display and Control (D&C) panel, a Portable Computer System (PCS), and an Artificial Vision Unit Cursor Control Device (AVU CCD). Unlike the external components, which are moved between the Lab and the Cupola, the internal components are fixed into the Lab racks. The internal components include an AVU and a Control Electronics Unit (CEU) which houses the RWS software. It means that there are two RWS racks (LAB and CUP), but only one set of "external components", which is shared between the two RWS ? During STS-133 EVA1, Cupola's RWS failed, and they had to use LAB's RWS. It means that they had to transfer all external components ?
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Space Pete
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« Reply #1879 on: 04/14/2012 05:33 PM » |
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I would like to clarify the capabilities of the different grapple fixtures used on USOS...
I don't understand what is an EFGF.
Also, I don't understand the usefulness of transmitting a video signal between SSRMS and its payload... An EFGF is an Electrical Flight Grapple Fixture - think of it as an FRGF with the capabilities of a PDGF. So, I hear you ask, why not just use a PDGF? Well, as I'm sure you know, PDGFs can only transmit their power/data/video through the SSRMS, and not other arms such as the SRMS or JEM RMS, since their LEE design is different. So EFGFs are used when payloads for arms other than the SSRMS need to have power/data/video transmission capabilities. EFGFs were only used on the OBSS, and currently, the JEM RMS SFA. With regard the usefulness of transmitting a video signal between SSRMS and its payload via a PVGF, let's think back to STS-132. Remember that PVGFs also provide power (power is needed for the cameras on the payload that provide the video) - so your table is incorrect in that regard. Back on STS-132, when the SSRMS was installing MRM-1 to FGB Nadir, the SSRMS needed video views from MRM-1 in order to make sure the alignment with the docking port was correct. So a PVGF was used to transmit video from MRM-1 to the operator, through the SSRMS. A PDGF was not needed since no other data apart from video was needed from MRM-1, thus using a PDGF would have been wasting the data capability (PDGFs are maybe more expensive than PVGFs I think, thus are only used when they are needed). So, here's a corrected version of your table: | Name | Power | Data | Video | | PDGF | Yes | Yes | Yes | | EFGF | Yes | Yes | Yes | | PVGF | Yes | No | Yes | | FRGF | No | No | No |
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Nicolas PILLET
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« Reply #1880 on: 04/14/2012 06:18 PM » |
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Thank you Pete for this clear answer.
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Robotbeat
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« Reply #1881 on: 04/14/2012 11:21 PM » |
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Is there one that can transfer fluids? Or, rather, has that ever been seriously considered?
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Space Pete
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« Reply #1882 on: 04/15/2012 03:14 PM » |
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Is there one that can transfer fluids? Or, rather, has that ever been seriously considered?
No, there isn't one that can transfer fluids, and I don't think it's ever been seriously considered - no real need up to now. Interesting idea for a next gen Canadarm though...
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erioladastra
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« Reply #1883 on: 04/16/2012 12:35 AM » |
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Found in the ISS Familiarization Manual :
The RWS has components which are either external or internal to the rack. The external components, illustrated in Figure 8-6, are portable and include three video monitors, a Translational Hand Controller (THC) and a Rotational Hand Controller (RHC), a Display and Control (D&C) panel, a Portable Computer System (PCS), and an Artificial Vision Unit Cursor Control Device (AVU CCD). Unlike the external components, which are moved between the Lab and the Cupola, the internal components are fixed into the Lab racks. The internal components include an AVU and a Control Electronics Unit (CEU) which houses the RWS software.
It means that there are two RWS racks (LAB and CUP), but only one set of "external components", which is shared between the two RWS ?
During STS-133 EVA1, Cupola's RWS failed, and they had to use LAB's RWS. It means that they had to transfer all external components ?
Correct - the SSRMS is dual string but functions as a unit controlled by ONE primary RWS. So when the RWS goes down it either has to be rebooted and configured or you swap to the other if it is up and configured as hot backup.
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d3jf
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« Reply #1884 on: 04/16/2012 11:58 AM » |
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It means that there are two RWS racks (LAB and CUP), but only one set of "external components", which is shared between the two RWS ?
I'm no expert, but isn't it quite the opposite? That is, a single rack with the AVU and CEU in the Lab, and two RWS - one set up in the Lab and one in Cupola, the latter being configured as primary. If I'm right, how does the CUP RWS communicate with the internal components in the Lab?
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Space Pete
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« Reply #1885 on: 04/16/2012 01:12 PM » |
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I'm no expert, but isn't it quite the opposite? That is, a single rack with the AVU and CEU in the Lab, and two RWS - one set up in the Lab and one in Cupola, the latter being configured as primary.
If I'm right, how does the CUP RWS communicate with the internal components in the Lab?
No, there are two RWS racks - and by that I mean two MSS avionics racks, located at Lab Port 6 & Lab Starboard 6. The Lab RWS at Port 6 is mounted and connected directly to its MSS avionics rack, whereas the Cupola RWS is connected to its MSS avionics rack at Lab Starboard 6 through routed cables between the Cupola, Node 3, Node 1, and Lab.
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d3jf
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« Reply #1886 on: 04/16/2012 02:02 PM » |
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Thanks for the explanation!
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Nicolas PILLET
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« Reply #1887 on: 04/17/2012 12:47 PM » |
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I'm no expert, but isn't it quite the opposite? That is, a single rack with the AVU and CEU in the Lab, and two RWS - one set up in the Lab and one in Cupola, the latter being configured as primary.
If I'm right, how does the CUP RWS communicate with the internal components in the Lab?
No, there are two RWS racks - and by that I mean two MSS avionics racks, located at Lab Port 6 & Lab Starboard 6. The Lab RWS at Port 6 is mounted and connected directly to its MSS avionics rack, whereas the Cupola RWS is connected to its MSS avionics rack at Lab Starboard 6 through routed cables between the Cupola, Node 3, Node 1, and Lab.
So, if the Cupola's RWS fails (as it was the case during STS-133), you have to use the second RWS (Port 6). But why do you have to transfer interfaces ? It would be easier to re-route Cupola's interfaces, in order to connect them to Port 6...?
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Space Pete
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« Reply #1888 on: 04/17/2012 01:19 PM » |
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So, if the Cupola's RWS fails (as it was the case during STS-133), you have to use the second RWS (Port 6). But why do you have to transfer interfaces ? It would be easier to re-route Cupola's interfaces, in order to connect them to Port 6...?
I should imagine swapping over a few hand controllers and monitors would be vastly quicker than re-routing cables through the CBM vestibule and/or standoffs from one side of the Lab to the other - especially given all the other cables that would become entangled in the process.
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majormajor42
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« Reply #1889 on: 04/20/2012 11:43 PM » |
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It was just mentioned in another thread that ISS crews enjoy sleeping in ATV. Would love to know more about this but would have been off-topic in that thread.
Why sleep in ATV?
Do all crew members have the option of where they sleep? Perhaps only Cosmonauts sleep on the Russian side where ATV is?
I think I also recall a Japanese astronaut slept in the ELM-PS. Perhaps it is nice to sleep in the more remote "corners" of the ISS that may be quieter?
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