Moon Walkers.

[picowatt]

Actually, regarding the flags, it appears they were indeed off the shelf nylon flags:

https://www.hq.nasa.gov/alsj/ApolloFlags-Condition.html

PW

[tinman]

   

For work that I do here I have an entire library of woven metal mesh.  I have stainless steel, bronze, brass, copper, aluminum, Monel, Nickel and a few more exotic materials with weaves up 1200 wires per inch.  Some of these mesh are more flexible than and feel softer than a lot of synthetic cloth weaves. 

NASA used a lot of woven mesh in various applications.  Some of the most expensive, and at the time, leading edge technology, were used in the glove of the space suit.  On the LEM, for example, the darker material of thermal insulation seen on the outside in the areas of the nozzle exhaust incorporated a nickle mesh.

When I look at your flag closeup, all I can see is that it appears that it might be made from a woven material, or possibly even a non-woven material.  Apparently, I do not have the same magic powers (or closed mindedness) as you do and cannot tell what that material is from just looking at the image.

PW

A mechanical engineer of any kind, which apparently you are not, would be able to look at the design of the LEM, including those outer panels you scoff at, and appreciate the high degree of research, design, and engineering that went into the design solution arrived at.  The outer panels are like a lightweight tent suspended away from the inner structures.  They are connected to the inner structure by standoffs using as few of them as possible to reduce thermal conduction between the outer and inner walls.  The outer panels were overlapped, somewhat like shingles, and where they overlapped, the panels were chemically milled to reduce their thickness to reduce unnecessary weight.

I can see i am going to have to dig up my old pictures of the gas/diesel power turbine i was a part of constructing,and show you how easy it is to apply insulation and cladding neatly,and withstand temperatures far greater than the LEM would have ever seen.

Then you seem to think that the lunar rover would be very hard to design and build to withstand G forces on take off,handle the pressure to vacuum drop in space,along with a mix of other thing's,but at the same time,have us all believe that those piles of junk can do it with ease 

I actually wasted a few moments of my life and watched the "analysis" of the first two images discussed in this video.  They are very keen on being focused on and discussing, the background, but it is the foreground that one should instead pay attention to.

Indeed.
I am guessing that you were thinking i posted that video,and provided a link to the very pictures use in that video,to show the Lunar module changing position-right?. But what dose it show you?-and in almost every picture that shows a great distance to the background hills/mountains-->thats right-false background drops added to the photographs. So i thank you for pointing out the obvious PW.

During the trip to the moon, the CM and LM were slowly rotated to prevent heat from building excessively on the sun facing side.  Because of this, the thin outer panels saw heating and cooling differentials that made them expand and contract.

Mmm,well i will admit that i am not sure on that one PW,and the reason being the following.
As space is an !almost! perfect vacuum,there would be no cooling by way of convection. So as the sun light heated 1 half of the space craft,and the other half that was in the sun light,is now in the shadowed side,how is that heat removed from that half of the space craft--it cannot be by way of convection,and there is only the other half of the space craft to conduct it's heat to,but that half is in the sun,and heating up. So how is the heat collected from the sun dissipated from the space craft PW ?. We know here on earth that the heat would be dissipated by way of convection due to our atmosphere,but how is it dissipated in the vacuum of space where there would be no convection dissipation ?.

And just exactly how can you determine what the flag is made from by just looking at it?

Are you kidding me PW ?.
Do you not know polyester when you see it?. It is certainly not aluminum foil of some sort.


Brad

[tinman]

  In recent posts you asked what the temperature on the moon was and I provided you with the extremes that I have seen published (+/-200C).  Those temperature extremes are of the lunar surface temperature.  There is no "air" so there is no other temperature to discuss.  The temperature of any object on the moon will depend on its reflection and absorption properties with regard to the solar flux to which it is exposed.

Here on Earth, if the surface temperature were +200C, the air temperature would be very hot indeed, because air is a pretty good conductor of heat, particularly when compared to a vacuum.  Surely most are familiar with a vacuum thermos.  They are typically made from two walls of glass separated by a vacuum.  No heat can flow thru the vacuum by conduction.  But, thermal (infrared) radiation can flow thru the vacuum so the walls are typically metalized so as to reflect and prevent the flow of radiated heat.

So, now you are standing on the moon, in a vacuum thermos, so to speak.  Your temperature will depend for the most part on what you are wearing and whether you are in the direct sun or in a shadow.  If you are wearing a layered spacesuit that has reflective layers designed to efficiently reflect visible, IR, and UV wavelengths, even while standing in the direct sun, you will experience only a moderate rise in temperature.  In fact, if an astronaut has his back to the sun, his hands would be in his own shadow and would become cold very quickly.

Similarly, the LEM only needs to reflect away as much solar flux as possible using its outer layer of panels.  They are not perfect reflectors so their temperature will slowly climb.  As their temperature increases, they will tend to radiate away heat from their inner surface.  To reduce the flow of radiated heat, a layered thermal barrier (IR barrier) of insulation is suspended between (not touching) the inner and outer wall panels.  Because of the vacuum, the only other heat flow path between the inner and outer walls of the LEM is by way of conduction thru the standoffs that support the outer wall panels away from the inner wall.  A minimum number of standoffs were used to reduce this conductive heat path, and is why the outer panels have very few attachment points and are effectively draped over the inner structure in a tent like fashion.  The gold metalized mylar films used to wrap the struts and lower sections of the lander are also used to reflect infrared wavelengths and prevent those areas of the lander from becoming excessively hot.


You have asked how the astronauts handled the extreme cold of the lunar night.  A lunar day and lunar night are each 2 weeks long.  The astronauts were never on the moon during a lunar night.  In fact, NASA timed the lunar landings to occur during the lunar dawn (morning).  The surface temperature at that time was still relatively cool.   


(Surely the phases of the moon were explained to you in grade school science class.  Were you paying attention?  Does "28 days" ring a bell?)

PW

Once again you demonstrate an extreme ignorance of the subject matter.
In the vacuum of space or on the surface of the moon, there is no "air" to support conduction or generate convection.  All heat flow is by way of radiation and absorption.

I demonstrate an extreme ignorance?.
First up,conduction of heat is by way of absorption. When you have a hot piece of metal,and you place that hot piece of metal on a cold piece of metal,then some of the heat from the hot piece will conduct through to the cold piece,and the cold piece will absorb some of the heat from the hot piece-->the two are the same when heat transfer is by way of physical contact. You asked me how i was going to keep the electric motors cool,and my response was in regard to this,and i was talking about dissipating the heat from the motors through the !all metal! wheels to the moon's surface-->thus the question on how hot is the moons surface in sun light.

Convection and radiation are also the same in this case,where we are talking about the subject matter of dissipating heat in a vacuum. Both convection and radiation of heat are by way of transfer by mass motion of a fluid such as air or water when the heated fluid is caused to move away from the source of heat, carrying energy with it. Convection above a hot surface occurs because hot air expands, becomes less dense, and rises. As there is no air /atmosphere on the moon or in space,then there is no heat dissipation by way of convection-->as i have already stated in previous post.

So who is demonstrating an extreme ignorance of the subject matter ?.


Brad

[tinman]

I am sorry Tinman, but my respect for any intellectual prowess I may have credited you with in the past is dwindling rather quickly.  In fact, I am finding it hard to believe you were ever 27 years old.

With only the slightest amount of research into the design of the Apollo space suits, you would not be asking this silly question or poking fun using the Michelin man.

And yet you claim to be an "active" mechanical engineer and would lead us to believe you have an open and scientific mind...

PW.

I must say the same in your direction PW.
Maybe go back and read some of the thing's you posted.
E.G
1- your dispute in regards to my termination of convection and conduction of heat in relation to the subject at hand-->who is correct there?
2-The video i posted,where as you said we need to pay attention to the forground--which changes,and yet the back ground remained exactly the same--how is that i wonder?
3-You asking me how i came to the conclusion that the flag was some sort of polyester/plastic material--who was right on that one?.
4-and now the space suit. For this i ask you to post the pressure differential between the inside of the space suit,and the outside of the space suit. Use PSI if you can,and let's see what pressure these space suit's had to withstand. Once we have that pressure differential,we can produce a replication,and see it that material composite can withstand that pressure. Then we can also try and work out as to why the space suits do not puff up like the Michelin man. The picture provided shows no sign's of the space suits being under extreme pressure,and yet we know that the men inside will not be subject the the very low pressure of space,and it will be a low pressure,as 0 pressure can only be obtained in an absolute vacuum--which space is not,but very close too.

Brad

[picowatt]

I can see i am going to have to dig up my old pictures of the gas/diesel power turbine i was a part of constructing,and show you how easy it is to apply insulation and cladding neatly,and withstand temperatures far greater than the LEM would have ever seen.

Which would have next to nothing to do with the requirements of spaceflight.

Could you even model the degree of protection needed to prevent damage from micrometeorite strikes and as well do it with not one gram more weight than is necessary?  Would you even be able to accurately model micrometeorite strike or thermodynamic requirements?  If you cannot appreciate the engineering used in the LEM, it only reflects on your limitations.  As a mechanical engineer, you should be in awe of the task that was at hand and the simple yet heavily tested and well engineered solutions arrived at.

The fact that you think you could do better with regard to spaceflight, is delusional.

Then you seem to think that the lunar rover would be very hard to design and build to withstand G forces on take off,handle the pressure to vacuum drop in space,along with a mix of other thing's,but at the same time,have us all believe that those piles of junk can do it with ease 

You really should visit a shake and bake facility.  Perhaps they don't exist in Australia.  It is very apparent you are out of your league and know not of what you speak.  That you feel yourself qualified to critique the Apollo designs is in itself delusional.

Indeed.
I am guessing that you were thinking i posted that video,and provided a link to the very pictures use in that video,to show the Lunar module changing position-right?. But what dose it show you?-and in almost every picture that shows a great distance to the background hills/mountains-->thats right-false background drops added to the photographs. So i thank you for pointing out the obvious PW.

And now you would have me believe that you are an imaging expert as well...
 

Mmm,well i will admit that i am not sure on that one PW,and the reason being the following.
As space is an !almost! perfect vacuum,there would be no cooling by way of convection. So as the sun light heated 1 half of the space craft,and the other half that was in the sun light,is now in the shadowed side,how is that heat removed from that half of the space craft--it cannot be by way of convection,and there is only the other half of the space craft to conduct it's heat to,but that half is in the sun,and heating up. So how is the heat collected from the sun dissipated from the space craft PW ?. We know here on earth that the heat would be dissipated by way of convection due to our atmosphere,but how is it dissipated in the vacuum of space where there would be no convection dissipation ?.

You know so little about the thermodynamics of space or on the moon, but somehow feel qualified to make judgements regarding the hard work and engineering of those that do.  Do you believe the space shuttle or the ISS were/are real?  Do you believe those geosynchronous satellites beaming weather and video to you are real?  How about those LEO GPS sats?  They all have to deal with the issue of getting rid of heat in space.  I have provided clues to the answers in discussing an astronaut on the moon, but really, if you are going to critique Apollo, or any other space related system, I think you should take the time to research just how it is done first.

This is like you saying that scientists have it all wrong when you have know idea or understanding of what it is those scientists know.

Are you kidding me PW ?.
Do you not know polyester when you see it?. It is certainly not aluminum foil of some sort.

No, I am not kidding, you cannot tell what that material is just from looking at the image.