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Post by scooter on Nov 19, 2005 23:26:14 GMT -4
dang lun-areodynamics!!! I missed that post!
I like the LRV operations manual where they use the term "lurain", almost casually...like the "remove before flight" streamers attached to various GSE bits on the ouside of the spacecraft.
To be so intimately involved with hardware that "went there", I am so jealous of those wrench turners, they have "touched" it.. Dave
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Post by scooter on Nov 19, 2005 11:19:25 GMT -4
Moon Man's signature line looks really ironic now... Indeed Al, excellent observation.
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Post by scooter on Nov 19, 2005 11:27:34 GMT -4
There's a ridgeline in front of the mountain. Where does NASA give this information...is the ridgeline between this photo spot and the mountain? The LM and the mountain? Trying to determine distances on the Moon was a huge challenge for the astronauts, they always underestimated distances, this began with A11...
Dave
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Post by scooter on Nov 19, 2005 22:04:17 GMT -4
Jeesh, I don't have the book, but know the answer...(it's on most of the "AB" sites)
It's a poorly done composition, a fakery, a depiction for Al Shepards book. Nothing more...just an artists attempt to depict how it might have looked...
NOT a NASA photo, nor ever claimed to be. You really can do better than this, can't you?
Dave
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Post by scooter on Nov 18, 2005 22:02:49 GMT -4
"We need a hatch with explosive bolts"...from the movie "The Right Stuff". And the Mercury (early 60s) astronauts got them, ask John Glenn, and the rest, about their skinned knuckles when hitting the actuator after splashdown...
The shuttle, the politics involved, a nightmare. But, basically, it was a NASA/government decided change in direction, in very simplistic terms. NASA, in the meantime, IMHO, did a hell of a job with it...
Dave
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Post by scooter on Nov 20, 2005 23:48:06 GMT -4
So, Moon Man, given the evidence, do the suits work, or not? If not, why not? I believe we have pretty well cleared up your misconceptions thus far. (aside from a general "disbelief", based on lack of understanding of how stuff works...) What's the next topic?
Dave
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Post by scooter on Nov 20, 2005 10:14:10 GMT -4
Moon Man, You state that since the suit was "leaking" (we're talking fractions of a cc of O2 per hour here), then radiation must also be leaking in. What kind of radiation? Rays? Particles? Radioactive gasses from the lunasphere? Were the leaky joints the entry points to contaminate the astronauts? I just want to make sure we have your counterpoint clearly understood. The 18 layer suit was quite robust and designed for the environment they encountered, as were the spacecraft. Dave
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Post by scooter on Nov 20, 2005 1:04:17 GMT -4
Where are you getting this 8 extra pounds? The upgrade (to double the EVA time) was about .75 lbs for all the LiHO canisters. Where's the proof???
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Post by scooter on Nov 19, 2005 23:43:35 GMT -4
and, again, being interchangable and identical, they still have the same weight and LiOH load/weight.
I don't see proof of a hoax here, nor even "evidence".
Dave
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Post by scooter on Nov 19, 2005 23:04:40 GMT -4
exactly how much weight per canister was "wasted"? If the canisters were "identical", what's the weight difference? I still don't understand the 14 hr thing, but did see it in the ALSJ link. re the LM secondary cartridge. The PLSS docs clearly show a shorter time for the "same" cartridge. But again, where is the weight difference? Dave
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Post by scooter on Nov 19, 2005 22:46:58 GMT -4
Obviousman, Thanks for the ALSJ link,my DSL chewed on it for a while but worth the wait! It does seem to confirm the numbers. Now, a bit of a question. In my favorite link, the -7 PLSS consumption/duration curve has two LIOH lines, one for "LiOH (min performance, nominal wt 3.22 lbs, no thermal soak)" and one for "LiOH(min performance, min wt 3.12 lbs, with thermal soak)"
I'm not sure what the "thermal soak" and "min wt" variables affect. The two lines converge significantly on the "BTU/hr - EVA duration curve, so the difference diminishes over time in the EVA.
Again, terrific link, gobs of neat stuff there...
Dave
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Post by scooter on Nov 19, 2005 21:53:33 GMT -4
From Obviousman's link on the PLSS...
"...To support the more ambitious exploration plans for Apollo 15 through 17, the PLSS operational lifetime was doubled to 8 hours. The changes made to the PLSS were:
Oxygen capacity: Pressure in the primary oxygen bottles was increased to 1430PSIA from 1020PSIA
Feedwater for cooling: Increased to 11.5 pounds (about 5.2 liters) from 8.5 lbs (about 3,9 liters).
Battery: Capacity increased to 390 watt-hours, from 279 watt-hours
Lithium Hydroxide: canister increased to hold 3.12 pounds of LiOH, up from 3.0 pounds.
Now, whats this about a 14 hour canister? ...do you have some data here? .12 pound increase per canister times 6 is .72 pound, about 12 ounces...total, earth weight. All these weight increases to double the EVA duration, seems a great tradeoff..
Dave.
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Post by scooter on Nov 19, 2005 20:52:23 GMT -4
You don't believe it so it can't be true? This isn't evidence, not is it proof of anything, except yhat you don't know the motivations behind those making the decisions. Is it possible they made decisions that don't agree with your thinking? Or mine? Quite likely... So the crew carried 6 LH2 to the surface in the LM. 3.12 lbs each, which equates to about 8oz on the moon, x6=3lbs total lunar canister weight. I suppose the question would be, what would be the weight of a 7 hour canister vs the longer duration version? Quite likely not much less, as the structural weight of the canister is a significant portion of the total weight. Your quibbling over ounces, the canister weight was minimal considering their criticality. There were other places on the LM that they chose to shave weight off. If push came to shove, they'd leave a small rock behind. The scrubbers were very important, I don't see a great mission wrecking weight penalty here.
Dave
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Post by scooter on Nov 19, 2005 20:19:06 GMT -4
Dave et al, weight was an issue with NASA. Why would they add a 14 hour lithium hydroxide canister when they know they can only do a maximum 8 hour EVA..? Each astronaut used one canister on each walk. There were therefore 6 canisters on board creating 8 pounds or so extra needless weight to the LM and Saturn Rocket. This extra weight, 1 point whatever pounds per canister, was also required to be needlessly carried around by the astronauts on each EVA. Please don't give a lame excuse like it's only a faction of that in 1/6 gravity. There were priorities in weight, life support no doubt being near the top. The weight of that extra LHO2 was deemed worthy of the extra safety cushion it allowed. We're talking small weight here, unnoticable to the astronauts during EVA ...yes, 1/6 their earth weight (no excuse, just fact). Do you find your pants heavy? NASA made a decision to provide the extra scrubber capacity, at minimal weight penalty, and that's it. Just because we don't always understand the "whys" doesn't mean it didn't happen. Keep swinging... Dave Dave
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Post by scooter on Nov 19, 2005 12:48:52 GMT -4
The Space Suit. The Apollo Space Suit design consisted of a zipper closing. It is questionable how this zipper never leaked. It also had joints for the waiste, gloves, boots and helmet, and all of which were subject to leakage. I think it is impossible to believe that it was completely ait tight, and while I cannot prove it, I challenge you all to explain how it did not leak..? And bear in mind that if air was escaping then radaition was entering the suit. How is it possible no astronaut became sick after being exposed for 22 hours..? The actual suits the astronauts were wearing still exist and are on display and could be tested for leakage. Leakage would eat up valuable oxygen. they were never really on the moon. I tried to grab the first snippet of your argument, even this alone raises several arguments... Yes, the outer garment was secured by a fairly conventional "zipper". This is referred to in the document as the "restraint" zipper. It is the zipper on the outer garment which secures the garment. This zipper is not designed to be airtight. There is a pressure garment, integral to the suit, which has a seperate "zipper", called the pressure seal. Think of it as an elaborate version of a zip-loc bag seal. It is the "gas seal" that keeps the pressure in the suit. It has a multi-part latch system ensuring the closure is secure and won't come loose. While designed to ve virtually "air tight", there is a tiny amount of leakage, which is measurable and understood. This "leak rate" is taken into account in the design of mission planning, but amounts to slightly more than 1/100 of a percent per hour. Leakage of the wrist, and helmet seals is part of this calculation...ot basically amounted to nil, but was still watched and monitored. So, basically, the "zipper" question is a non factor, the "fabric" zipper was not required not designed as a gas seal...there was an inner seal for this. Also you mention "as air leaks out, radiation gets in". Radiation doesn't behave like a gas. In toxic atmospheres, a positive pressure suit is used to ensure toxins don't enter the suit (matter flows from areas of greater pressure to areas of lesser pressure, not the other way around). But, again, radiation leakage in such areas doesn't apply. OK, that's the first of the many arguments you presented....any questions? Dave
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