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I'm curious what strategy they'll use to find it.

@mikegarrison said that releasing smoke or something like this won't work because it would just lead to the air cleaning system. Would it be possible to disable the air cleaning system for a while (a few hours maybe) without endangering the crew too much?

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9 minutes ago, s_gamer101 said:

I'm curious what strategy they'll use to find it.

@mikegarrison said that releasing smoke or something like this won't work because it would just lead to the air cleaning system. Would it be possible to disable the air cleaning system for a while (a few hours maybe) without endangering the crew too much?

I'm sure that's possible. They would likely want to do it on a module-by-module basis. I don't think they would want to just shut off the entire system unless they had to. I don't know the exact details of their system configuration, though, so I don't know which systems and modules are too integrated to isolate.

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https://www.sciencealert.com/oxygen-supply-has-failed-in-part-of-the-international-space-station

Another problem with ISS life support; nothing that would be an immediate threat to crew though.

"Nothing threatens the security of the crew and the ISS," said the spokesperson, adding this repair work to fix the issue would be carried out on Thursday.

The ISS is getting old :/ I wonder if it's just a matter of time that something serious comes up.

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On 10/16/2020 at 10:14 PM, kurja said:

The ISS is getting old :/ I wonder if it's just a matter of time that something serious comes up.

I think what might happen is that the decide to take it out of service (returning the crew to the surface and deorbiting the station)

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Apparently they're going to overlay the existing arrays, angled out at 10 Deg. Sized to go uphill rolled up in a dragon trunk, which sounds incredible to me.

 

 

 

 

This offends my sense of symmetry tbh.

 

Edited by RCgothic
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2 hours ago, RCgothic said:

Apparently they're going to overlay the existing arrays, angled out at 10 Deg.

How does that work ? Wouldn't it mean it'd just work on one side of the wing array ? Would it be the new side of the wing array or what ? I could imagine that the idea is to increase the effectiveness of the arrays... since not all the light are absorbed you can still put a PV behind another one and it'd work albeit less efficiently compared to direct illumination, but it'd increase the efficiency of the whole system wrt. the exposed area of the array.

I wonder if it's the same solar panels that'd be used for Gateway and other Artemis missions.

Edited by YNM
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On 1/12/2021 at 10:10 AM, YNM said:

How does that work ? Wouldn't it mean it'd just work on one side of the wing array ? Would it be the new side of the wing array or what ? I could imagine that the idea is to increase the effectiveness of the arrays... since not all the light are absorbed you can still put a PV behind another one and it'd work albeit less efficiently compared to direct illumination, but it'd increase the efficiency of the whole system wrt. the exposed area of the array.

I wonder if it's the same solar panels that'd be used for Gateway and other Artemis missions.

The panel trusses have a gimbal mechanism so one side tracks the sun, keeping that side fully illuminated. It looks like the new panels will permanently shade parts of the old panels, but they are much more efficient, so it will cancel out - the original panels could generate up to ~220kW when installed , but that has now dropped to 160kW over the last 15-20 years. The new panels generate an additional 120kW, and will bring power generation back up to 220kW, so it appears about 60kW is being shaded / lost. I suspect they probably can't increase power output much above the original 220kW as the ISS solar charge controllers (or whatever the ISS equivalent is) won't be designed for it.

The difference in size between the two arrays neatly illustrates the improvements made in panel efficiency over the last 20 years or so.

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I still don't get it. Solar panels tend to react to shading the same way a water pipe network reacts to a pipe being pinched: even if it happens in just one location, it reduces the flow throughout the entire system. 

Also, if the old arrays have deteriorated, why not replace them entirely instead of laying new arrays on top of them?

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On 1/15/2021 at 1:57 AM, Codraroll said:

I still don't get it. Solar panels tend to react to shading the same way a water pipe network reacts to a pipe being pinched: even if it happens in just one location, it reduces the flow throughout the entire system. 

Also, if the old arrays have deteriorated, why not replace them entirely instead of laying new arrays on top of them?

I wondered about this as well. After I had panels put on my roof I soon noticed a dip in electricity output twice a day at roughly the same time. I realised the shadow from a small vent pipe was passing across part of one panel and then another panel a bit later, and it caused the whole string of panels to decrease their power output. I had to cut the pipe a bit to resolve that. There are options for shade as well - most modern panels have bypass diodes, and you can get optimisers or micro inverters for each panel that bypass shaded panels/cells as well, so I suppose the ISS array must be designed in a way that compensates well for the effect of shading.

I'd assume the old arrays are more trouble than its worth to replace entirely, especially if they are still productive. Not sure how they'd be disposed of either.

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1 hour ago, Listy said:

I wondered about this as well. After I had panels put on my roof I soon noticed a dip in electricity output twice a day at roughly the same time. I realised the shadow from a small vent pipe was passing across part of one panel and then another panel a bit later, and it caused the whole string of panels to decrease their power output. I had to cut the pipe a bit to resolve that. There are options for shade as well - most modern panels have bypass diodes, and you can get optimisers or micro inverters for each panel that bypass shaded panels/cells as well, so I suppose the ISS array must be designed in a way that compensates well for the effect of shading.

I'd assume the old arrays are more trouble than its worth to replace entirely, especially if they are still productive. Not sure how they'd be disposed of either.

I'm sure disposal wouldn't be much of  a problem, they're light and have a large surface area. Give them a little push away from the station with whatever you're using to uninstall them and the people back on Earth will be breathing them in a few months. I imagine not having a reason to dispose of them is the main reason they're staying.

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Maybe they are afraid of letting this thing  uncontrollably floating after separation?

Quote

Together the arrays contain a total of 262,400 solar cells and cover an area of about 27,000 square feet (2,500 square meters) -- more than half the area of a football field. A solar array's wingspan of 240 feet (73 meters) is longer than a Boeing 777's wingspan, which is 212 feet (65 meters).

Quote

So is EACH IEA a cube 5 meters on a side weighing 7.7 metric tons, or are ALL FOUR of these IEAs, in total, these dimensions?

The total mass of the ISS is ~390 metric tons, and the radiators are huge, so the total mass of these four IEAs COULD weigh ~30 metric tons in total.

 

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12 hours ago, RyanRising said:

I'm sure disposal wouldn't be much of  a problem, they're light and have a large surface area. Give them a little push away from the station with whatever you're using to uninstall them and the people back on Earth will be breathing them in a few months. I imagine not having a reason to dispose of them is the main reason they're staying.

Detaching them while being opened is an exercise in believing I suppose.

Plus, there might not be an actual simple way to undo the panels off from the truss, and you'd still be left with the truss itself which I'd assume is even more difficult to undo. I'm sure they want to keep the rotating hinge itself since it's pretty difficult to send a new one then undo the old one... Then again during assembly we've moved the thing several times around the station so idk. Maybe when we have the European Robotic Arm as well, and a crew of 11 instead of 7.

Edited by YNM
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8 hours ago, Canopus said:

They can't do this! My lego model wouldn't be accurate anymore!

Have you pierced it in several places to leak?

56 minutes ago, YNM said:

Maybe when we have the European Robotic Arm as well

The solar panels are Western, so unlikely they are equipped with grappling fixtures for Soviet/Russian "Aist", used, afaik, by the European Arm.

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On 1/17/2021 at 1:10 AM, kerbiloid said:

The solar panels are Western, so unlikely they are equipped with grappling fixtures for Soviet/Russian "Aist", used, afaik, by the European Arm.

Ah alright... I though they'd have replaceable heads or something for the ERA.

Edited by YNM
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