Freedomain Radio

pretzelogik:

Haven't really found anything that would meet the size, weight, output capacity and discharge requirements of cooling a sheet metal stage prop, er Lunar Excursion Module down from 300° to something liveable.

Please confirm ("yes" or "no") whether you now accept that it's quite practical to have a 65 kW-hr battery aboard a craft the size of the LEM.

If "yes", we can move on to looking at how much power is needed to maintain a comfortable temperature inside the LEM in the lunar daytime environment.

Is the question here really about batteries?

I'd like to know what makes the author of the thread an expert in physics, astronomy, geometry. A degree? Training in the military? What has you so convinced that you think cardboard can even survive the temperatures exceeded during the arduous event of reaching an escape velocity? I don't think the escape rockets used are built out of sheet metal either. I have bent furnace plenums from sheet metal. I don't think they use this material in spaceships because it would melt before it escaped Earth's atmosphere.

Are you prepared to go all the way and say that other countries faked moon landings too?

The manhattan project. Huge secret. Huge, terrifying results. Was not fake. Big science at work. Don't believe science? Ok? Ok. Then show us your science.

The point is I am not convinced.  The photos show what appears to be a flimsy sheetmetal and cardboard contraption covered in tin foil.  Earlier I posted the before and after photos tasken from NASAs website.  The first photo was what actually convinced me.  At the time it was featured in all it's contrived glory.  Since then, I imagine NASA got wind of the number of people downloading and critically examining the photo, so they replaced it with a blown out version that masks some of the obvious weaknesses.  So, yes I am saying sheet metal and cardboard would be less than suitable for interstellar travel.  Ergo, no moon landing.  And yes, I think the other countries faked it too.  Behold, The Lunokhod!  Designed by Jules Vern (or so it would appear), for the RUssian astronaughts to collect Antarctic meteorite samples, I mean moon rocks, from the lunar surface.

I would accept that it's quite practical to have a 65 KW battery, evidently so did NASA that's what they said the one aboard took care of all the power needs of the LEM for 3 days. The Prius battery is said to be somewhere from 44 to 65 KW and fits in a Prius which looks somewhat smaller than the lunar lander.  So, in terms of size, the battery in a Prius would fit within the stated confines of the space in the LEM.

pretzelogik:

I would accept that it's quite practical to have a 65 KW battery, evidently so did NASA that's what they said the one aboard took care of all the power needs of the LEM for 3 days.

OK, so let's start to look at the numbers for the power needs. To do the precise calculations would require an equivalent design effort to that used by NASA, which obviously I can't do. Instead, I will look at some simple calculations to establish some ballpark figures. If any of these is problematic, it can be calculated more precisely. You mentioned temperature maintenance, so I'll start there.

The crew cabin of the lunar module has a volume of 6.7 cubic meters. Assuming a cubic shape (for simplification), this means a surface area of 21 square meters.

I don't know what type of thermal insulation was used, but it would be at least as good as ordinary expanded polyurethane (which is routinely used in building applications). This insulator has a thermal resistivity of around 1.4 meters squared Kelvin per watt-inch. Let's solve for Watts, using an assumed insulation thickness of 2 inches, and an inside-outside temperature difference of 200K.

This gives 21m^2 * 200 K / 2 inches / 1.4, which equals 1500 watts. Over 72 hours, this would require 108 kW-hours. OK, the first rough calculation needs a bit too much power. But wait! We have a highly-reflective layer on the outside. This alone has a thermal resistivity of around 10, or 12.8 when we add it to the two-inch expanded polyurethane layer.

Now we need a power consumption of 21 * 200 / 12.8 which is 328 watts, or 23 kW-hours, which is well within the capacity of our batteries. Of course those batteries must do lots of other things too, but I hope this "back-of-the-envelope" calculation has shown that it's entirely plausible.

At this point I should mention some other things. The crew module was deliberately placed on the side of the LM that would be in the shade during the mission, which would have reduced the power requirement somewhat. Oh, and the LM cooling was actually provided by ice sublimation rather than by electrical power, so it imposed no load on the batteries anyway.

Are you prepared to accept that the need to cool the LM doesn't in itself make the mission implausible? If so, we can investigate some other aspect of the mission.

pretzelogik:

Earlier I posted the before and after photos tasken from NASAs website.  The first photo was what actually convinced me.  At the time it was featured in all it's contrived glory.  Since then, I imagine NASA got wind of the number of people downloading and critically examining the photo, so they replaced it with a blown out version that masks some of the obvious weaknesses.

OK, I found the source of this photo on NASA's website:

http://spaceflight.nasa.gov/gallery/images/apollo/apollo11/html/as11-40-5927.html

Notice that there are links to a "high res" and "low res" version of the photo. The "high res" version, naturally, shows more detail.

So it's simply incorrect to say that NASA "replaced" the original with a "blown out version", since both versions are linked to with equal prominence.

Are you prepared to withdraw your assertion that NASA withdrew the original high resolution version?

This image I posted IS more blown out than the one you posted, low res or not.  Compare the circle on the back pack of the astronaught, it's invisible in the pic I posted - the contrast  is markedly increased.  Nonetheless, I found that pic, by searching, NASA, missions or images, Apollo or whatever, and so on til I found it and was surprised how different it was.  Check for yourself it is quite different.  Anyway, I can't find it on their site now, through simple clicking and linking or hardly any other Apollo pictures and/or especially the videos.  This in itself should be enough.  The moonwalk is undoubtedly the pinnacle of NASA achievement, it's like winning an olympic gold medal in 5 categories in a single year and posting tweets about your favorite breakfast cereal all over your web page instead. Of course they are available on google, but that is not the point.

Anyway, as far as heating/cooling and insulation here is a close up example of the LEM:

You can believe this defied extreme death-inducing heat/cold and vacuum if you like.  Oh and check for and type of propellent cratering under your posted picture of that LEM.  Oh, yeah...

ribuck:

Are you prepared to withdraw your assertion that NASA withdrew the original high resolution version?

pretzelogik:

This image I posted IS more blown out than the one you posted, low res or not.

I take that as a "yes" then, i.e. you no longer assert that NASA withdrew the original high resolution version.

pretzelogik:

Anyway, as far as heating/cooling and insulation here is a close up example of the LEM:

You can believe this defied extreme death-inducing heat/cold and vacuum if you like.

Do you realise that these sheets do not need to withstand any lateral pressure, nor retain any air, because they have a vacuum on both sides? They are not structural elements. They just cover the aft equipment bay and reflect some heat away.

A spacecraft that operates only in a vacuum is designed very differently from one that must also operate while passing through the earth's atmosphere.

(This is tiresome. You don't give the impression that you're interested in a process of rational investigation.)

ribuck:

Do you realise that these sheets do not need to withstand any lateral pressure, nor retain any air, because they have a vacuum on both sides? They are not structural elements. They just cover the aft equipment bay and reflect some heat away.

Not only that but the damage to the panels was made worse when the ascent module lifted off. That photo is from the Apollo 16 mission and was taken from this photo of the Orion capsule.

Later, when the ascent stage was approaching the command module, another photo was taken, with the Aft Equipment Bay (covered in damaged panels) to the left and the craft upright, in much the same orientation as the first photo. Note the dish on the right side of the craft.

The Apollo 16 post-mission report concluded that the panels becamed loosened somehow during the descent and then were damaged further during ascent. Jokes about the driving ability of the Orion pilot can easily be found around the internet. It also noted that the temperature inside the bay was higher than expected, due to the damage.

Anyway, the Aft Equipment Bay was unpressurized and contained only batteries and cooling equipment. The loose panels functioned only to shield equipment from the heat. 

Ribuck, you are awesome. Pretzelogic (hmm interesting, considering your comments) I know nothing will ever change your mind about this issue but I find the discussion interesting. I'd like to hear some more. Maybe I will post about the lack of crater underneath the LM when I get home from work in a few hours.

Aye, now thar's a sea-worthy vessel if I ever saw one!  Shiver me timbers!

I assure you, you wouldn't be shivering in a million-dollar pressurized spacesuit paid for off the backs of, well, you're probably one of those backs.

There's a plethora of science to prove your assertions false, sir. I am not disappoint.

Au revoir.

I am sorry, pardon my lack of understanding of physics and all that fancy scientific stuff.  I live in Florida and I know that in order for us to make indoor living bearable we try to limit the exchange of elements from inside to outside as much as possible, i.e., keeping the cold air in and the hot air out.  I know if the local Home Depot weatherization specialist tried to sell me windows with gaps like the ones pictured I might have some issues.  Thankfully, since I breathe H20, I don't live in a vacuum separated from another vacuum by a few thin sheets of loosely riveted metal.  Maybe you could step me through this process, since you obviously have the capacity of understanding the fancy physics and explain exactly what type of material was used to provide an air tight atmosphere that would keep all the cool air generated by the ice sublimation, due to them being parked on the shady side of the moon, pictured above, inside the Lunar Stageprop, er lander.  Although that sure looks bright for the shady side,  And since you are so familiar, was it airtight?  Maybe they were just exposed to the vacuum all the while breathing, liquid oxygen and being kept cool by the water running through their suits in the 300* heat, which somehow didn't make that water in those suits boil.  Or freeze when they were in the shade, at minus 200*. I am sure there are quite reasonable explanations for all this, and since I am such a science novice, I just need a little help understanding it all.  I mean it would take a lot of convincing for someone to get me to leave my dog in that contraption for a few hours in the Florida heat, but hey, there were 3 of our nation's finest prancing around up there going in and out of it like it was a tree house, so what do I know?  Just give me a little run down on how the atmosphere was maintained.;  Oh, and it couldn't fly.  But you probably knew that.  Below: Neil Armstrong 1968.  1969, NO PROBLEM

I think even if you came to the conclusion in your own mind that at least some of your beliefs are wrong, you wouldn't let it show here. Just an observation.

pretzelogik:

Thankfully, since I breathe H20

you breathe water? that's amazing! xD

and here i was thinking people only breathe air ---> (by volume) 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases.

"Sure looks bright for the shady side"? I tell you what, pretzelogic, why not re-read my posts. It is the airtight CREW CABIN that was on the shady side of the LUNAR LANDER. The part you are looking at is an EQUIPMENT BAY on the sunny side that's not supposed to be airtight. You do realize that what you are seeing in the photo is not the exterior of an air-filled cabin? The crew cabin is not visible in that photo, and is only a small part of the lunar module.

Of course you would not buy windows from Home Depot like that. But if you just wanted to keep the sun off your fuel can it might do the job, even in a Florida summer.

As for the water in their spacesuits boiling at 300 degrees, they did not use water for cooling, but a water-glycol mixture that remains liquid within the entire range of temperatures encountered on the lunar mission. Heat pipes containing water-glycol were also used to move heat around the lunar module, to the ice sublimators.

"Pardon my lack of understanding of physics and all that fancy scientific stuff". Hmm. Without physics, your only chance of disproving the lunar landing is to expose the process of the fraud. It's intellectually unreasonable of you to raise scientific objections if you don't understand science.