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Power situation in the ISS Russian Segment has degraded
"James Oberg" wrote in message ... Something to keep an eye on.... SM batteries: Battery #4 is disconnected (failed 6/16); battery #7 is in "Cycle" mode; all other batteries (6) are in "Partial Charge" mode. Batteries #1, #2 and #3 showing degraded capacity. FGB batteries: Battery #3 is offline; all other batteries (5) are in "Partial Charge" mode. Good grief - are these nightmare things to change out? Chance to whack them on the next progress perhaps? Doug |
#2
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Power situation in the ISS Russian Segment has degraded
"Doug Ellison" writes:
Good grief - are these nightmare things to change out? Chance to whack them on the next progress perhaps? The Russians have quite a bit of experience with changing these sorts of batteries in orbit. The problem is that these batteries are big and heavy. With the shuttle grounded, there is a bit of an uplift problem right now. Jeff -- Remove "no" and "spam" from email address to reply. If it says "This is not spam!", it's surely a lie. |
#3
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Power situation in the ISS Russian Segment has degraded
On Thu, 3 Jul 2003 13:30:00 -0400, "Rick C" wrote:
"jeff findley" wrote in message .. . "Doug Ellison" writes: Good grief - are these nightmare things to change out? Chance to whack them on the next progress perhaps? The Russians have quite a bit of experience with changing these sorts of batteries in orbit. The problem is that these batteries are big and heavy. With the shuttle grounded, there is a bit of an uplift problem right now. Sounds like a bit too much experience. Hope they're researching more reliable batteries. Maybe the folks doing off-grid solar homes could help out with some suggestions. Or talk to the phone company about Edison cells. :-) They last for many decades with proper care. Of course the energy storage density isn't very good, and the traditional wet cell design wouldn't work so well in zero G either. I assume, not having seen it spelled out, that these batteries are sealed NiCads. They do have a limited cycle life. Gary |
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Power situation in the ISS Russian Segment has degraded
Gary Coffman writes:
On Thu, 3 Jul 2003 13:30:00 -0400, "Rick C" wrote: "jeff findley" wrote in message .. . The Russians have quite a bit of experience with changing these sorts of batteries in orbit. The problem is that these batteries are big and heavy. With the shuttle grounded, there is a bit of an uplift problem right now. Sounds like a bit too much experience. Hope they're researching more reliable batteries. Maybe the folks doing off-grid solar homes could help out with some suggestions. Or talk to the phone company about Edison cells. :-) They last for many decades with proper care. Of course the energy storage density isn't very good, and the traditional wet cell design wouldn't work so well in zero G either. I assume, not having seen it spelled out, that these batteries are sealed NiCads. They do have a limited cycle life. Please note that the charge/discharge cycle of the batteries on ISS is one discharge and one charge *per orbit*! At the rate that ISS orbits the earth, you are really putting the batteries through a tough duty cycle. Why don't you try that sort of duty cycle on a consumer grade battery and see how long it lasts? If you search for "Russian service module batteries" on Yahoo!, you'll find out that the batteries on the Russian side are nickel-cadmium. Early on, batteries (and their charging controllers) in both Zarya and Zvezda had problems and several were replaced. I can't find a figure for the weight of one of these batteries, but have found articles that say Zvezda module was launched with just five of its eight batteries in place, "to save weight". I have a feeling these things may be "bigger than a breadbox". Jeff -- Remove "no" and "spam" from email address to reply. If it says "This is not spam!", it's surely a lie. |
#5
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Power situation in the ISS Russian Segment has degraded
On Thu, 03 Jul 2003 13:22:27 GMT, "James Oberg"
wrote: [Of the eight 800A storage batteries in the SM, one is completely unusable (#4), and three more units (#1, #2, and #3) are showing reduced capacity (i.e., inability to fully charge). The EXP-2 crew (Usachev, Helms, Voss) replaced what would have been 2/3 of the EXP-7 crew (Malenchenko, Lu) on STS-101/2A.2a (which got split into 2A.2a and STS-106/2A.2b) in order for them to be able to do battery replacement on the SM back in 2001. Which batteries did they replace? I seem to remember something about this being close to their normal lifetime anyway. |
#6
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Power situation in the ISS Russian Segment has degraded
"Rick C" writes:
"jeff findley" wrote in message ... "Doug Ellison" writes: Good grief - are these nightmare things to change out? Chance to whack them on the next progress perhaps? The Russians have quite a bit of experience with changing these sorts of batteries in orbit. The problem is that these batteries are big and heavy. With the shuttle grounded, there is a bit of an uplift problem right now. Sounds like a bit too much experience. Hope they're researching more reliable batteries. Maybe the folks doing off-grid solar homes could help out with some suggestions. Not a solution now, but why can some of the battery capacity on ISS not be replaced with something much more reliable? I am thinking flywheels. Spin them up when you have excess energy and used them to generate power when you need it. Of course you would always use a pair of counter rotating flywheels to keep torque transferred to the station at zero. -- Manfred Bartz |
#7
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Power situation in the ISS Russian Segment has degraded
Not a solution now, but why can some of the battery capacity on ISS not be replaced with something much more reliable? I am thinking flywheels. Spin them up when you have excess energy and The vibration would kill microgravity research. |
#8
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Power situation in the ISS Russian Segment has degraded
Manfred Bartz writes:
Nonsense. There are 4 large flywheels operating on the ISS right now, the CMGs (control moment gyros). Actually, only 3 are in operating condition at this time :-( |
#9
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Power situation in the ISS Russian Segment has degraded
In news:Hallerb typed:
Nonsense. There are 4 large flywheels operating on the ISS right now, the CMGs (control moment gyros). Actually, only 3 are in operating condition at this time :-( Yeah but were talking of much bigger more powerful ones who speed will vary a lot over time, putting and taking power as needed. You can add so much stuff like this that research will be impossible... Do you *ever* admit you screwed up when someone calls you on an error? Obviously you know you were wrong because you snipped your error out. But just once it would be nice to see just a touch of humility that you don't have all the answers around here. Sheesh. -- Mike __________________________________________________ ______ "Colorado Ski Country, USA" Come often, Ski hard, Spend *lots* of money, Then leave as quickly as you can. Rec.Skiing.Alpine.Moderated is up and working! Join in! |
#10
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Power situation in the ISS Russian Segment has degraded
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