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Post by rmc on Oct 9, 2015 14:45:24 GMT
Martian atmosphere is one percent that of Earth's. Would Martian wind storms blow with enough force to throw a dish antenna into a man and send him head over heels for twenty feet?
On a second issue: Would these same winds not have the strength to knock a marker flag out of the soil?
Could the largest vacuum chamber on Earth be used to reproduce Martian atmosphere pressures to test any of this out? Would a wind tunnel inserted into such chamber suffice to recreated wind velocities necessary? If not, some sort of secondary chamber that could release air pressure to create wind?
Some ideas for this thread include:
1. Wind or dust forces 2. Repairing damaged Mars habitat 3. Making water 4. If dried blood could somewhat seal a pressure suit
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Post by GTCGreg on Oct 9, 2015 15:13:17 GMT
Martian atmosphere is one percent that of Earth's. Would Martian wind storms blow with enough force to throw a dish antenna into a man and send him head over heels for twenty feet? On a second issue: Would these same winds not have the strength to knock a marker flag out of the soil? Could the largest vacuum chamber on Earth be used to reproduce Martian atmosphere pressures to test any of this out? Would a wind tunnel inserted into such chamber suffice to recreated wind velocities necessary? If not, some sort of secondary chamber that could release air pressure to create wind? On the first question (dish antenna) I would think it's possible. The maximum wind speeds recorded on Mars, by the Viking Landers in the 1970's, was about 60 miles an hour. I'm sure a large solid dish that broke loose from it's mounting could do some serious damage. A 60 mph wind uprooting a marker flag, sure. And as far as the Martian wind simulator, I would think you could do that at standard earth atmospheric density. You would just have to calculate the wind speed, which would be lower than on Mars, to produce the same force under reduced Martian atmospheric density. A little math goes a long way.
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Post by rmc on Oct 9, 2015 18:50:50 GMT
Since Force = Mass * Acceleration would need the differing air mass for each equation. And momentum = mass * velocity so, here again need the air mass. Since Martian density is one percent Earth's and since density = mass over volume, maybe finding a usable number for both air masses is straight forward?
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Post by GTCGreg on Oct 9, 2015 18:59:32 GMT
Since Force = Mass * Acceleration would need the differing air mass for each equation. And momentum = mass * velocity so, here again need the air mass. Since Martian density is one percent Earth's and since density = mass over volume, maybe finding a usable number for both air masses is straight forward? I think the equation you would want to use is F=1/2M*V 2As can be seen, velocity is the squared term and carries much more effect on the force than the mass does. Still, the mass does carry some weight (yes, that's a pun)
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Post by rmc on Oct 9, 2015 19:15:44 GMT
So, we are looking at kinetic energy rather than direct force? Wait. Isn't the correct formula the one that describes drag? \_(''/)_/ And, what distance would you say the astronaut was thrown? I guessed twenty feet, but it looks to be more. And, I realize Martian gravity isn't as much as Earth's, so that would help him be thrown farther than on Earth, but as far as seen in the film? Including the idea that the astronaut was already partially lifted by the winds before he was hit by the object, and that this would cause him to be thrown further than if in stagnant air, because he is carried along by the moving wind besides the force of the collision. Still, even with that, one percent mass of air seems too thin to do all that was depicted. (went ahead and called it one percent mass since in the equation for density, we'd use the same volume for a given space, so those would cancel, leaving us with mass: d1 = m1/v and d2 = m2/v
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Post by GTCGreg on Oct 9, 2015 19:52:56 GMT
So, we are looking at kinetic energy rather than direct force? Wait. Isn't the correct formula the one that describes drag? \_(''/)_/ And, what distance would you say the astronaut was thrown? I guessed twenty feet, but it looks to be more. And, I realize Martian gravity isn't as much as Earth's, so that would help him be thrown farther than on Earth, but as far as seen in the film? Including the idea that the astronaut was already partially lifted by the winds before he was hit by the object, and that this would cause him to be thrown further than if in stagnant air, because he is carried along by the moving wind besides the force of the collision. Still, even with that, one percent mass of air seems too thin to do all that was depicted. (went ahead and called it one percent mass since in the equation for density, we'd use the same volume for a given space, so those would cancel, leaving us with mass: d1 = m1/v and d2 = m2/v I'm no expert on aerodynamics. All I do know is the faster I drive, the worse mileage I get. As far as the flying astronaut, I haven't seen that movie yet, although it looks like a good one. Maybe when it comes to a theater near me. (spelled Netflix)
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Post by rmc on Oct 9, 2015 23:10:10 GMT
Thanks, GTCGreg!
One other question involved making an airtight cover for a damaged habitat on the surface of Mars, using a single ply of plastic, duct tape and a ratcheted cinching strap, but I think I may need to limit my questions since you and possibly many others haven't see the movie as yet?
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Post by GTCGreg on Oct 9, 2015 23:51:30 GMT
Thanks, GTCGreg! One other question involved making an airtight cover for a damaged habitat on the surface of Mars, using a single ply of plastic, duct tape and a ratcheted cinching strap, but I think I may need to limit my questions since you and possibly many others haven't see the movie as yet? Not knowing what I'm talking about has never stopped me in the past.
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Post by the light works on Oct 10, 2015 1:14:27 GMT
I'm thinking there would ultimately need to be a vacuum wind tunnel test to make the audience happy.
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Post by silverdragon on Oct 10, 2015 13:33:29 GMT
I know earth bound physics will not apply on Mars.
For starters, I am guessing weight issues may alter the thing. Being that atmosphere is 1%th of earth, as stated, would dish antenna's need to be " as sturdy" as earh ones?.. no. So saving weight on the outbound flight, would they be any more than a sort of (earth standard) fragile umbrella plastic thing that would be quite adequate on Mars, or are we going for the full stalactite TV type thing you see in back gardens the whole world over.
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Post by the light works on Oct 10, 2015 14:30:13 GMT
I know earth bound physics will not apply on Mars. For starters, I am guessing weight issues may alter the thing. Being that atmosphere is 1%th of earth, as stated, would dish antenna's need to be " as sturdy" as earh ones?.. no. So saving weight on the outbound flight, would they be any more than a sort of (earth standard) fragile umbrella plastic thing that would be quite adequate on Mars, or are we going for the full stalactite TV type thing you see in back gardens the whole world over. stalactite TV, was that on purpose? if so I like it, if not, that's some absurd autocorrect thing. as I recall from basic space fizzicks, you have to work with all three variables of force, weight, and mass. in freefall you can pick up a ton of bricks and throw it at somebody, but it will take a while, and when it hits them it will hit them like a ton of bricks. so perhaps it takes a bit of time for the wind to get the thing moving (force vs. mass), but less actual wind power (power vs friction from weight), and when it does, it just plows over the guy (mass vs force)
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Post by silverdragon on Oct 11, 2015 7:23:43 GMT
Well... it was a Firefox suggested correction, but hell, it fits, and I was in too much of a hurry to notice... Karma is a beach, I just picked up on one of yours elsewhere and made a joke. We aint the spelling natzi here, but the occasional typo can be hummus?. (Firefox suggested Humorous there...) Eggsactomundos, you can play with the variables in all of that to create a lightweight for transport usable variant on usual earthbound objects, but the only thing you cant change is the Human. Therefore, the human is in a 1/100th atmosphere with a LOT of mass, aint no storm going to blow them over?... To be honest, I am wondering if the real hazard would be possible puncture to the space suit, and thats not a meteorological thung?... a 100 mph "wind" on Mars when blowing past a human mass is no more than a gentle sea breeze on earth?... Comparing the particles of atmosphere per second that is... The wind "Drag" on the object would be extremely low, the ability to move that object also extremely low. Of course, the mass and "gravity" forces now have to play. A decent "Wind" on the Moon, if that could ever exist, would move stuff about a hell of a lot if the moon had an atmosphere because the moon has such low gravity, and even with a low wind drag factor, friction keeping stuff in place is low because of the lack of gravity. So, does anyone know the exacts of gravity on Mars?.. I suppose its best we work with that for comparisons here... Assuming that site is correct, I have finded a bloody good reference site to use... www.universetoday.com/14859/gravity-on-mars/Its worth reproducing, so next post will do that, just for sake of interest. Ripping from that source, with Gravity being 38% of earth's, it still has gravity, but not as much. In that case, if you WERE blown over, yeah, you would travel quite a bit. But... At a wind speed/force of not-a-lot bang for the blast, would you get picked up and thrown at all?... My guess would be that would have to be a HELL of a wind to do that. And how would you measure wind speed there?... an anemometer (Did you mean Anteater?) would have to be about 99times as big as on earth to "catch" enough force to turn it?...
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Post by silverdragon on Oct 11, 2015 7:29:42 GMT
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Post by silverdragon on Oct 11, 2015 7:38:49 GMT
Just a note here, on a visit to that actual site, a British comedian is heard on his documentary after climbing into the "space suit", to say somthing along the lines of "I have an itchy nose, just how the hell do you scratch an itch in one of these things?..."
So there is the question, on an EVA, if you get "sweat in your eyes" or an 'itch' somewhere, how do you deal with that?... I suspect they are trained to ignore?..
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Post by rmc on Oct 11, 2015 14:10:55 GMT
Nice write ups! As to reducing gravity, in a vacuum chamber brought down to one percent Earth's atmospheric pressure, I'd assume tethered balloons could be used to simulate a lower gravity field.
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Post by the light works on Oct 11, 2015 14:54:51 GMT
Just a note here, on a visit to that actual site, a British comedian is heard on his documentary after climbing into the "space suit", to say somthing along the lines of "I have an itchy nose, just how the hell do you scratch an itch in one of these things?..." So there is the question, on an EVA, if you get "sweat in your eyes" or an 'itch' somewhere, how do you deal with that?... I suspect they are trained to ignore?.. I believe they are supplied with a cyanide capsule for a worst-case scenario. I think some suits have a tool for dealing with sweat. it may do double duty on an itch.
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Post by silverdragon on Oct 11, 2015 15:07:00 GMT
Now I believed the "hood" type thing they wear under the helmet to be an absorbent material that should soak up sweat, and it does cover well down the brow... I have worn "similar" under a motorcycle helmet whilst on track, and it did soak up sweat that may have got into the eyes... Except.... I dont know, I think maybe my head got warmer because of the extra layer under there?... I think I remember one saying that the "pipe" supplied for water could be used if you bent you head in the right way. Still.... I have my old helmet up there on the shelf. The greatest ever invention in a helmet is the nose guard..... goes over the nose, comkpletely. Sneezing in a helmet, there is only one thing worse, and thats an angry wasp. Anyone recognising this...?..
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Post by the light works on Oct 11, 2015 15:21:48 GMT
Now I believed the "hood" type thing they wear under the helmet to be an absorbent material that should soak up sweat, and it does cover well down the brow... I have worn "similar" under a motorcycle helmet whilst on track, and it did soak up sweat that may have got into the eyes... Except.... I dont know, I think maybe my head got warmer because of the extra layer under there?... I think I remember one saying that the "pipe" supplied for water could be used if you bent you head in the right way. Still.... I have my old helmet up there on the shelf. The greatest ever invention in a helmet is the nose guard..... goes over the nose, comkpletely. Sneezing in a helmet, there is only one thing worse, and thats an angry wasp. Anyone recognising this...?.. never thrown up in a respirator, have you?
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Post by silverdragon on Oct 11, 2015 15:42:38 GMT
Ok, so, try the following, throw up in a respirator and sneeze in a helmet. You can hold your breath until you stop.... You cant "wipe" the inside of a visor at 80mph.............
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Post by silverdragon on Oct 11, 2015 15:43:07 GMT
We are a little off topic?...
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