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Post by gwiz on May 24, 2007 9:17:18 GMT -4
Do particles leave a spinning tire tangentally? More or less. There is actually a spread of directions due to the details of how the tread of the tyre interacts with the dust.
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Post by donnieb on May 24, 2007 17:11:17 GMT -4
Hey, cool! Incidentally, CSM is the Command and Service Module (which you probably knew), and the MCC-H is short for Mission Control Center in Houston. Not sure what the event refers to though. Without knowing exactly where in the mission this notation occurred, I'd say it likely refers to uploading a new program into the Guidance Computer to cover the next phase of the mission. This would occur at various points, like along the trans-lunar coast (to overwrite the TLI program with a program for a mid-course correction or lunar orbit insertion).
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Post by nomuse on May 24, 2007 19:05:39 GMT -4
Heck, that was my guess.
Going back a bit, I wonder if there is some substance natural, processed, or fabricated that might behave like the fine particles visible in medium to long shots? (Treating the problem of dust behavior in close shots as a different problem.) Assuming you are to film in atmosphere, whatever you used (and the rest of your equipment) would have to be extremely clean. If your final goal was merely youTube-quality compressed video you might get away with a little airborne dust here and there, but the clarity of the scene out to horizon strongly argues for an excruciatingly clean set.
And whatever you used would have to be a large enough particulate size so as to show little visible influence by atmosphere during the small flight paths wanted (aka flung from wheels and boots) -- or, at least, a small surface relative to mass -- but a small enough size to, within the limits of the video resolution, appear as a fine dust. It would also be good if it showed a small amount of clumping, and excellent if it was capable of taking a boot impression.
So far all my mind comes up with is birdshot. Lots and lots of steel pellets (of the smallest size available) -- perhaps magnetized slightly (although that would be difficult to control.)
Any thoughts? Any takers?
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Post by Count Zero on May 24, 2007 19:48:41 GMT -4
So far all my mind comes up with is birdshot. Lots and lots of steel pellets (of the smallest size available) -- perhaps magnetized slightly (although that would be difficult to control.)
I see two problems right off the bat:
First is that, although they might follow the desired quasi-ballistic trajectory, the coarser grains would not sit on the ground in a manner that moondust does. For example, it would not be impressable and take a footprint the way we see in the Apollo images.
Secondly, steel pellets are hard and not compressable, so that when the airborne particles landed on the surface, they would likely bounce. I do not see anything like that happening.
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Post by nomuse on May 24, 2007 21:04:42 GMT -4
Hrm. Hadn't thought about bounce. That could be a problem. Maybe lead pellets....perhaps instead of spherical bearings, cast into properly jagged shapes?
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Post by Cavorite on May 24, 2007 21:54:22 GMT -4
I dread to think how tired the astronauts would get kicking lead up as far as they do every step.
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Post by gillianren on May 25, 2007 18:18:50 GMT -4
Um . . . it's got pictures from 'em. I'm not sure if they've been reframed or not, if that's the question you're asking. And given that I'm trapped in place by my sleeping cat and my sleeping boyfriend (the joys of having a computer set up so that you can use it in bed!), I can't really get the book right now.
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Post by svector on May 25, 2007 19:03:25 GMT -4
Um . . . it's got pictures from 'em. I'm not sure if they've been reframed or not, if that's the question you're asking. And given that I'm trapped in place by my sleeping cat and my sleeping boyfriend (the joys of having a computer set up so that you can use it in bed!), I can't really get the book right now. I'd be interested to know how many stills it contains from those missions. There's an HB on YT (more acronyms, ASAP!) who claims there is no pre-1990 publication with more than a few of the hi-res Hasselblad stills, currently in circulation.
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Post by gwiz on May 26, 2007 5:15:23 GMT -4
Has Rocky given up on this one? His recent posts have all been to other threads.
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Post by gillianren on May 26, 2007 15:42:42 GMT -4
There's a mosaic from Surveyor. There's a few pasted-in photo plates, including one (that looks reframed to me, but no numbers, I'm afraid) of Buzz "gingerly test[ing] the lunar surface," among other things. There's a reproduction of a strip of the film. There's a picture of Buzz setting in place the solar wind experiment. Buzz getting core samples. Buzz carrying the seismic detector and the laser reflector.
Looking it over, most of the shots appear to be taken from the Hasselblad, but again, no shot numbers. (Ooo! Buzz, Neil, and Michael Collins smiling awkwardly at Nixon!) There are also pages of transcript from the mission itself. The more I look over this book, the happier I am with it.
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Post by Grand Lunar on May 26, 2007 15:58:02 GMT -4
Has Rocky given up on this one? His recent posts have all been to other threads. I'm willing to bet he's searching for more videos on Google and YouTube to do his thinking for him.
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rocky
Earth
BANNED
Posts: 212
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Post by rocky on May 29, 2007 7:12:04 GMT -4
I still think the footage was filmed on earth. Here's some clearer footage of it. www.youtube.com/watch?v=npARfNtO7u8The dirt is going up and the curve is not continuing symmetrically as it would in a vacuum. It is encountering atmosphere and falling down in a very unsymmetrical curve. It can't be explained by the particles being close together and following slightly different paths or any of that other stuff you came up with. This is not a vacuum. In a vacuum dirt would follow a symmetrical parabolic curve after being launched into the air.
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Post by Jason Thompson on May 29, 2007 7:21:52 GMT -4
Here's some clearer footage of it.
I don't care what clear footage you can find online, I can find the clearest footage in my DVD collection.
This is not a vacuum. In a vacuum dirt would follow a symmetrical parabolic curve after being launched into the air.
Which bit of 'you are not looking at the trajectories of individual dirt grains' don't you understand? We are not bound to share the comclusions of a man who can't grasp basic science and freely admits to not understanding most of it anyway.
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Post by Kiwi on May 29, 2007 7:42:25 GMT -4
Surely, Rocky, you could convince all of us if you simply picked out a readily-identifiable dust particle (one that, even if it tumbled, could not be confused with another) and traced its trajectory frame by frame by frame by frame by frame by frame by frame... and presented us with an appropriate gif.
It would be even more convincing if you did it with 100 particles.
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Post by Grand Lunar on May 29, 2007 7:54:45 GMT -4
Rocky, have you actually read what the problem is with your thinking? Each individual dust grain is following its own path. What we see in the footage is thousands of these grains. Now, the tire is spinning over uneven terrain. It's speed changes due to resistence from the dirt. So, each individual particle has a different path. Therefore, in the footage, the thousands (if not more) of dust grains appear in the fashion we see. Because we can't pick out each individual grain (you'd like'y need a microscope to see them), it has the appearence we see in the video. Do you comprehend this? While your're at that, answer this issue too.[Edited by LunarOrbit to fix your link]
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