Author Topic: "Foil & duct tape" on the landers  (Read 1316 times)

Offline Flookie

  • Mercury
  • *
  • Posts: 23
"Foil & duct tape" on the landers
« on: March 04, 2017, 09:25:36 PM »
I believe somebody on Youtube is going to link me to this photo or something similar as part of his belief Nasa is covering up the earth being flat (no comment).

http://space.stackexchange.com/questions/5899/why-does-the-ascent-stage-of-apollo-11s-lunar-module-look-like-its-made-of-pap/5900

While there's a good (I assume) explanation on the page I'm not clear what the "gold tape" on the thermal layers is or why the panels at the top left of the picture appear ill-fitting (distorted?). Would someone enlighten me?
Thanks.

Edit: I found this link:
http://home.earthlink.net/~pfjeld/lmdata/
Satisfactory to pass on to someone?
« Last Edit: March 04, 2017, 09:31:57 PM by Flookie »

Offline Glom

  • Jupiter
  • ***
  • Posts: 950
Re: "Foil & duct tape" on the landers
« Reply #1 on: March 05, 2017, 03:19:56 AM »
The foil is mylar, used to reflect sunlight and the duct tape is industrial adhesive strips, a fair but stronger than your domestic equivalent.

Offline smartcooky

  • Saturn
  • ****
  • Posts: 1408
Re: "Foil & duct tape" on the landers
« Reply #2 on: March 05, 2017, 04:12:54 AM »
I believe somebody on Youtube is going to link me to this photo or something similar as part of his belief Nasa is covering up the earth being flat (no comment).

http://space.stackexchange.com/questions/5899/why-does-the-ascent-stage-of-apollo-11s-lunar-module-look-like-its-made-of-pap/5900

While there's a good (I assume) explanation on the page I'm not clear what the "gold tape" on the thermal layers is or why the panels at the top left of the picture appear ill-fitting (distorted?). Would someone enlighten me?
Thanks.

Edit: I found this link:
http://home.earthlink.net/~pfjeld/lmdata/
Satisfactory to pass on to someone?

Sorry, I know they said don't laugh, but I couldn't help myself.
► What you can assert without evidence, I can dismiss without evidence
► When you argue with idiots you risk being dragged down to their level and beaten with experience.
►"Conspiracism is a shortcut to the illusion of erudition

Offline Flookie

  • Mercury
  • *
  • Posts: 23
Re: "Foil & duct tape" on the landers
« Reply #3 on: March 05, 2017, 05:06:31 PM »
The foil is mylar, used to reflect sunlight and the duct tape is industrial adhesive strips, a fair but stronger than your domestic equivalent.

Thanks!  :) Please don't tell me the tape is to cover up holes...? I look at the rectangular outline in tape and wonder if there was a rip they patched up?

Any idea on the ill-fitting panels?

Offline ka9q

  • Neptune
  • ****
  • Posts: 2836
Re: "Foil & duct tape" on the landers
« Reply #4 on: March 05, 2017, 08:12:29 PM »
The gold-covered foil is aluminized Kapton, not Mylar.

Kapton is orange/yellow, depending on thickness. Mylar is a greyish color. The main difference is that Kapton has a much wider temperature range, so it's used for external surfaces. The LM uses Mylar too, but it's hidden underneath Kapton or behind the micrometeroid panels on the ascent stage.

The rear surfaces have a very thin layer of vapor-deposited aluminum forming a "second surface mirror". Aluminum reflects all wavelengths well, while Kapton and Mylar are both opaque in the far infrared where objects near room temperature radiate most of their blackbody radiation. The material "looks" much darker in the far IR, meaning that it reflects incident sunlight (which is mostly visible and near IR) while efficiently radiating in the far IR. This keeps a surface cool in space even when exposed to the sun.

The LM actually used many layers of this material to form a "thermal blanket" that effectively blocks transfer in either direction. This insulated it from the extremes of space (particularly cold black sky) but also trapped waste heat. This was removed with a pumped liquid coolant. The warm coolant flowed through a sublimator that evaporated water to space to carry away the waste heat.

Offline bknight

  • Uranus
  • ****
  • Posts: 2140
Re: "Foil & duct tape" on the landers
« Reply #5 on: March 06, 2017, 04:02:03 PM »
...

The LM actually used many layers of this material to form a "thermal blanket" that effectively blocks transfer in either direction. This insulated it from the extremes of space (particularly cold black sky) but also trapped waste heat. This was removed with a pumped liquid coolant. The warm coolant flowed through a sublimator that evaporated water to space to carry away the waste heat.

I can't help myself, was it tested in a vacuum chamber with astronauts onboard. ::)
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline Flookie

  • Mercury
  • *
  • Posts: 23
Re: "Foil & duct tape" on the landers
« Reply #6 on: March 06, 2017, 07:44:33 PM »
I can't help myself, was it tested in a vacuum chamber with astronauts onboard. ::)

Chilling out?

Offline ka9q

  • Neptune
  • ****
  • Posts: 2836
Re: "Foil & duct tape" on the landers
« Reply #7 on: March 07, 2017, 05:51:33 AM »
Actually yes. I don't know if every LM was vacuum tested with astronauts onboard, but there was definitely at least one such test each for the LM and for the CM during the design qualification process. Must have been a pretty thankless job, without even the consolation prize of zero gravity to make things more comfortable in such a cramped space.

Offline bknight

  • Uranus
  • ****
  • Posts: 2140
Re: "Foil & duct tape" on the landers
« Reply #8 on: March 07, 2017, 06:28:29 AM »
I can't help myself, was it tested in a vacuum chamber with astronauts onboard. ::)

Chilling out?
Actually it was as tongue in cheek remark of Mr. Baker's insistence that sublimators be tested in a vacuum chamber with an astronaut strapped to and using it.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline Count Zero

  • Mars
  • ***
  • Posts: 298
  • Pad 39A July 14,1969
Re: "Foil & duct tape" on the landers
« Reply #9 on: March 07, 2017, 03:26:17 PM »
"Better" still, he demanded film footage of the sublimator working.  <face-palm>
"What makes one step a giant leap is all the steps before."

Offline Count Zero

  • Mars
  • ***
  • Posts: 298
  • Pad 39A July 14,1969
Re: "Foil & duct tape" on the landers
« Reply #10 on: March 08, 2017, 02:48:47 AM »
I've always thought that looking at the outside skin of the Lunar Module, and deciding that it's construction is too flimsy was just plain weird.  This makes no sense.  Do they think their shirt is holding them upright in their chair?  No?  What about their skin - is that holding them up?

What is important is what's under the skin, so let's have a look at what's under the LM's skin:


Here it is one on the factory floor at Grumman Aviation in Long Island.
To the left is the Descent Stage.  Note that it is not actually octagonal, but rather is five box structures welded together, with vertical reinforcements rather like a wine box.  This provided fantastic vertical strength for the mass of material used; allowing it to support the weight of the Ascent Stage during Saturn V liftoff, and also for it to serve as a launch pad for the AS when it takes off.

To the right is the Ascent Stage.  You can see that the inner skin of the pressurized crew cabin is supported by closely-spaced ribs for maximum strength at minimum weight.  One of the ascent fuel tanks is visible to the right.


Here is the Ascent Stage of the LM,viewed from the right-rear.  To the right (partially obscured) is the drum-like crew compartment.  To the left is the aft electronics bay.  You can see the thin stringers from which the outer skin will hang, but don't get them confused with the much sturdier structural framework underneath that you can see supporting the AEB and oxidizer tank.


Here's another view of the Descent Stage, showing its rugged construction.  The descent fuel & oxidizer tanks are inside the boxes.  The triangular sections between the outer boxes were storage areas for auxiliary tanks and equipment the astronauts would need on the Moon, including tools, science packages and, on the later missions, the folded-up lunar rover.

Grumman, whose proud engineers built the Lunar Module, also built the best and most durable naval aircraft ever - they didn't do flimsy.


When I first saw pictures like this, I thought that they had formed the skin to the right shape, and then added the ribs, or that they built the rib framework and the attached the inner skin to it, like you would build a ship.

The reality is far more interesting and clever (and stronger):  The skin & ribs are a single block of aluminum!  They milled-down the sections between the ribs to the desired skin thickness.  They did this for each section of hull, then welded the sections together at strong edges.

Here are pictures of the pieces coming together with diagrams of where the sections fit.

Grumman went onto use the same technique to build the F-14 Tomcat.

Hope this helps

 8)
"What makes one step a giant leap is all the steps before."

Offline Glom

  • Jupiter
  • ***
  • Posts: 950
Re: &quot;Foil & duct tape&quot; on the landers
« Reply #11 on: March 08, 2017, 04:42:20 AM »
Nice pictures.

Remember a while back we had a lady come on here with similar arguments. After we said she needed to do more research, she said she was going to go away and do some and then return. I think the tone was suggesting that when she did she would be better placed to advance her argument. I don't think she ever did.

Offline gwiz

  • Mars
  • ***
  • Posts: 289
Re: "Foil & duct tape" on the landers
« Reply #12 on: March 08, 2017, 06:39:16 AM »
My normal response to this claim is suggest that they Google launch-preparation pictures of modern satellites, as they mostly have similar gold or black foil coverings.  Shows that there must be a good engineering reason for it.
Multiple exclamation marks are a sure sign of a diseased mind - Terry Pratchett
...the ascent module ... took off like a rocket - Moon Man

Offline Flookie

  • Mercury
  • *
  • Posts: 23
Re: "Foil & duct tape" on the landers
« Reply #13 on: March 08, 2017, 06:24:10 PM »
Hope this helps

Hopefully. I suspect the guy isn't going to reappear though; I pointed out when I asked to see the picture(s) he was talking about that Nasa would be unlikely to release such photos if they were intent on fooling people. That I could find one possibility on Google Image within seconds should mean he could provide a link easily.

Impressive pictures.

Offline Dalhousie

  • Mars
  • ***
  • Posts: 407
Re: "Foil & duct tape" on the landers
« Reply #14 on: March 09, 2017, 12:51:53 AM »
The gold-covered foil is aluminized Kapton, not Mylar.

Kapton is orange/yellow, depending on thickness. Mylar is a greyish color. The main difference is that Kapton has a much wider temperature range, so it's used for external surfaces. The LM uses Mylar too, but it's hidden underneath Kapton or behind the micrometeroid panels on the ascent stage.

The rear surfaces have a very thin layer of vapor-deposited aluminum forming a "second surface mirror". Aluminum reflects all wavelengths well, while Kapton and Mylar are both opaque in the far infrared where objects near room temperature radiate most of their blackbody radiation. The material "looks" much darker in the far IR, meaning that it reflects incident sunlight (which is mostly visible and near IR) while efficiently radiating in the far IR. This keeps a surface cool in space even when exposed to the sun.

The LM actually used many layers of this material to form a "thermal blanket" that effectively blocks transfer in either direction. This insulated it from the extremes of space (particularly cold black sky) but also trapped waste heat. This was removed with a pumped liquid coolant. The warm coolant flowed through a sublimator that evaporated water to space to carry away the waste heat.

So there gold coat was on top of the aluminium?