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#61
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"Jeff Findley" wrote:
Nothing is 100% safe. But the Russians clearly have more experience with space staions than the US. That's an undisputable fact. What is disputable is whether that experience is in fact worth anything. It provided them with a bin of spare designs and parts to base Zarya and Zvezda on, but beyond that the advantage is what? D. -- Touch-twice life. Eat. Drink. Laugh. |
#62
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The big question is whether work on the USA side ECLSS systems has
completely stopped with all the gear stowed in some wharehouse, or whether there is stull R&D and testing work being done. In other words: is NASA taking advantage of this very long delay to ensure that the systems that will eventually go up are extremely reliable ? Well, I don't know what work is currently going on, but the key word here is "eventually". Unless something has changed, the US ECLSS equipment is all planned for the Hab module (or Node 3, or whatever it is called this week). Which isn't even on the assembly sequence (I was looking at http://spaceflight.nasa.gov/shuttle/future/index.html ). I won't say it is impossible to do work now to improve equipment which won't be used for 5-10 years, but I will say that having someone who is using (or soon will use) the stuff you are building tends to improve the quality of the engineering. At least, that's been true on projects I've worked on. |
#63
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"bob haller" wrote in message ... dangerous unsafe unit. WE DO NOT KNOW WHICH APPLIES. But the possibility remains that it is still quite safe to operate. Yep. and columbia, foam shedding is safe Proof positive that anyone can make an unjustified assumption. You're doing exactly that in assuming that Elektron has the potential to "explode". You simply don't know one way or the other. Jeff -- Remove icky phrase from email address to get a valid address. |
#64
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"bob haller" wrote in message ... So does a fully charged cell phone dropped in the toilet, but that doesn't mean that the toilet is going to explode. Jeff cell phones dont intentionally break down hydrogen and oxygen... No, but they have battery packs that can release quite a bit of current. Add that to H20 and a few impurities (which can surely be found in an unflushed toilet), and you could certainly generate H2 and O2. Hell, I produced H2 and O2 from H2O back in second grade. All you need is water, a battery, some wire, and a bit of salt. A "proper" setup will generate H2 in one container and O2 in another. I'm sure you can find a description of this experiment on the web. Jeff -- Remove icky phrase from email address to get a valid address. |
#65
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"Derek Lyons" wrote in message ... "Jeff Findley" wrote: Nothing is 100% safe. But the Russians clearly have more experience with space staions than the US. That's an undisputable fact. What is disputable is whether that experience is in fact worth anything. It provided them with a bin of spare designs and parts to base Zarya and Zvezda on, but beyond that the advantage is what? They have the operational experience to know that things break. This means they know they have to plan for such events. It also means that they don't "freak out" as much as their US counterparts when something goes wrong. Of course, you'll point out that given their history with submarines, they appear to be less concerned with loss of hardware and loss of life than their US counterparts. I can't dispute that. Jeff -- Remove icky phrase from email address to get a valid address. |
#66
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"Jim Kingdon" wrote in message news Well, I don't know what work is currently going on, but the key word here is "eventually". Unless something has changed, the US ECLSS equipment is all planned for the Hab module (or Node 3, or whatever it is called this week). Which isn't even on the assembly sequence (I was looking at http://spaceflight.nasa.gov/shuttle/future/index.html ). I won't say it is impossible to do work now to improve equipment which won't be used for 5-10 years, but I will say that having someone who is using (or soon will use) the stuff you are building tends to improve the quality of the engineering. At least, that's been true on projects I've worked on. I've been waiting for someone "in the know" to tell us the state of future US ECLSS. I knew it was bad. I keep hoping that the US will find a way to get ECLSS up earlier than the "HAB", but it doesn't look promising. Jeff -- Remove icky phrase from email address to get a valid address. |
#67
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I've been waiting for someone "in the know" to tell us the state of future
US ECLSS. I knew it was bad. I keep hoping that the US will find a way to get ECLSS up earlier than the "HAB", but it doesn't look promising. I'm not in the know, but I can provide mostly-uninformed speculation ;-). The thing about ECLSS is that it requires various ducts, connections, software, and the like. It isn't just like an experiment rack where you plug it in, provide it with power, and it is ready to go. So I'm not expecting to see a retrofit which involves running a water line (for example) to an existing rack in the Lab or such. I could be wrong on this: maybe the existing lines go more places than I realize (I suppose Node 1, at least, would need to have plenty of them so that they can go to the eventual Hab). Could one design ECLSS in a more "appliance" like way? For example, having the astronauts carry the water over in a bag and put it into an oxygen generator manually from time to time? Possible, but it is a lot easier to do that kind of task without spilling in 1 g than weightlessness. Certainly the oxygen candles are an example of this kind of solution. Could one run semi-ad-hoc lines fairly easily using things like flexible tubing (all the rage in terrestrial plumbing these days, at least for some things)? Maybe, although I'm sure it wouldn't be a small task to run it behind the racks and it would perhaps get in the way if it is in front of the racks. I guess the biggest problem is getting through a hatch. The standard ISS solution, as I understand it, is a through-hull on each side, followed by an EVA to hook them up. Well, if the US LAB (for example) doesn't have the through-hulls, adding them on orbit seems .... unlikely. The Mir solution of course was just to run things through the hatch and having to unplug it if you ever need to close the hatch. I'm not sure even Mir did this for things like water and gas lines. And of course in cases like the crash and air leak, all the cables through the hatch were considered a problem. But yes, if anyone actually knows more about studies of ECLSS-before-Hab, I'd be eager to hear more about what problems of this sort came up, and what the proposed solutions were. |
#68
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"Jim Kingdon" wrote in message news I guess the biggest problem is getting through a hatch. The standard ISS solution, as I understand it, is a through-hull on each side, followed by an EVA to hook them up. For some things I think this is true. For others, you run the lines to fittings that attach with short connections in the vestibule area of the CBM's. That way you can work in shirt sleeves, but can still close the hatches without disconnecting anything. MPLM's use this feature of the CBM's, so documentation on MPLM to ISS interfaces go into some detail about these connections. One has to wonder if there are any existing or "extra" water connections at the various CBM's throughout the station that could be used for this purpose. But water is "easy" compared to dealing with the H2. You'd also need a connection to vaccuum so you could vent H2. I'm sure you'd want this to be a dedicated connection so there is zero chance of cabin air mixing with the H2 and going "boom". Jeff -- Remove icky phrase from email address to get a valid address. |
#69
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Jeff Findley wrote:
Of course, you'll point out that given their history with submarines, they appear to be less concerned with loss of hardware and loss of life than their US counterparts. I can't dispute that. Fair point. However, a submarine and the station do have significant differences: Submarine has a LOT of people tightly speezed. Station doesn't. As a result, the systems on a submarine are of a much larger scale, so if they go bezerk, the problem will equally be of higher scale. Here is a question: movies will often show smokers in a sub. Is that really tolerated ? Are the air scubbers so good that they do handle all that stuff ? Submarines are surrounded by far more pressure from SALT WATER, as opposed to a mere 14.7psi of vacuum. When it comes to salt water an batteries, which is, from what I was told, a huge potential for disaster in a sub, the station doesn't have that. In fact, doesn't the station rely on NiCad batteries instead of lead acid as submarines do ? (or do submarines now also have NiCad/NiMh batteries ?) The space station also does not have a nuclear reactor, nor does it have a slealth mission that requires it stay submerged no matter what. How many lived were lost in subs because the captain would not order the submarine to surface ? |
#70
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"Jeff Findley" wrote:
"Derek Lyons" wrote in message ... "Jeff Findley" wrote: Nothing is 100% safe. But the Russians clearly have more experience with space staions than the US. That's an undisputable fact. What is disputable is whether that experience is in fact worth anything. It provided them with a bin of spare designs and parts to base Zarya and Zvezda on, but beyond that the advantage is what? They have the operational experience to know that things break. Advantage: Unproven. The US knows full well that things break as well. This means they know they have to plan for such events. Advantage: Unproven. The US has long history of preparing repair procedures, planning alternate missions, providing backups.... It also means that they don't "freak out" as much as their US counterparts when something goes wrong. Unproveable emotional statement. Of course, you'll point out that given their history with submarines, they appear to be less concerned with loss of hardware and loss of life than their US counterparts. I can't dispute that. The weird part is they were inconsistent as hell with that attitude. D. -- Touch-twice life. Eat. Drink. Laugh. |
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