posted 09-30-2012 02:20 AM               

• the thickness of the floor where the astronauts were in flight position (before their dashboard);
  
• the thickness of the side walls

posted 09-30-2012 02:46 PM               

On my first visit to the Smithsonian in Washington in 1993, I was shocked at how thin the walls of the LM on display there at the time actually were. It's one of my abiding memories of that visit.

posted 09-30-2012 03:11 PM               

The single wall concept consisted of 1/8" aluminum or equivalent mass.

posted 09-30-2012 03:47 PM               

OK, looking at that again I saw where the cross section on that same page has the outer skin at 0.012 minimum which would make sence for 5 psi and add credibility to the oh-so-thin skin stories.

I believe the 1/8 reference may be the single skin thickness equivalent for the multi layer cross section shown on the same page.

posted 09-30-2012 06:15 PM               

The cabin floor was 2" thick honeycomb.

posted 09-30-2012 06:46 PM               

Crew Compartment

The crew compartment was cylindrical in section in a welded and riveted construction, 92 inches in diameter and 42 inches deep, giving a habitable volume of 160 cubic feet, just sufficient for the two crewmembers to stand side by side. Due to the weight saving programs the compartment skin was reduced to a thickness of 0.012 inches, the equivalent of approximately three layers of kitchen foil.

posted 10-01-2012 01:26 PM               

quote:

---

Originally posted by space1:
I mentioned that the pressurized cabin web thickness was specified as thin as "0.015 to 0.025" inches thick.

---

posted 10-03-2012 06:46 AM               

According to this ALCOA source, US aluminum beverage can walls were approximately 0.015 inches thick in the 1970s. According to this excellent Scientific American article from September 1994, The Aluminum Beverage Can, can wall thicknesses were reduced even further to 0.003-0.006 inches. This study shows that US aluminum soda cans with walls 0.005 inches thin can contain internal gas/liquid pressure loads of 50+ psi.

Moving away from aluminum pressure vessels, I wanted to check relevant dimensions of aluminum sheet and foil. According to this Aluminum Industry document, aluminum sheet is a product 0.008-0.249 inches thick (previously 0.006-0.249 inches), and aluminum foil is a product 0.0079 inches or less thick (previously less than 0.006 inches). Reynolds Wrap Aluminum Kitchen Foil varies in thickness from 0.00064-0.00137 inches as you progress from the standard product to the extra heavy product. So while the aluminum skin of the Apollo LM crew cabin may have been, in certain areas, the equivalent of 3 (very thick) layers of aluminum foil, that foil was not thin modern-day kitchen foil grade. Perhaps kitchen foil of the 1960s-1970s was an awful lot thicker!

Overall, the chem-milled aluminum skin was sufficiently robust for the lunar landing missions. While you may not have been able to push your finger through the side walls, a sharp pointed object or a stray foot may have resulted in disaster so care was needed. Andrew Chaikin wrote in A Man On The Moon (p156):

"In the ascent stage, the walls of the crew cabin were thinned down until they were nothing more than a taut aluminum balloon, in some places only five-thousandths of an inch thick. Once, a workman accidentally dropped a screwdriver inside the cabin and it went through the floor."

posted 07-05-2016 06:54 AM               

[Conrad, from the 1969 Tech Debrief - "The cabin went right down to 0.2 and then the spacecraft outgassed for about another minute, I guess, and we finally got down to 0.1 and Al peeled the cabin door open. You have to do this, or it just stays stuck until you push it open. It doesn't hurt the door or the seal or anything."]

[Jones - "Did you literally mean grab a corner of the hatch and peel it back?"]

[Conrad - "That hatch had some ribbing that you could get a hold of. You realize this whole vehicle was pretty tinny (that is, light weight and flimsy). So this thing was very easy to...He could actually pull a little corner open."]

[Bean - "And that let the rest of the air out, and then it would open. I remember we never could pull it open with the handle and we were worried about pulling on it too hard."]

[Jones - "So you just grabbed a corner and literally peeled it off like a band-aid."]

[Bean - "You're making a little crack."]

[Conrad - "Just bending the corner. Except, I think there was structure, stiffeners. So there was something he could grab a hold of something and pull it back."]

[Bean - "Just a little."]

[Jones - "And that was easier than the handle, itself?"]

[Bean - "Well, yeah, it's like opening anything that's under pressure. When you're pulling the handle, that makes you open all this surface area against 0.1 psi. But, when you're pulling back the corner, you're only moving a little bit of it. And the thing was so flexible. It was one piece, machined titanium or something, and so thin that it was ridiculous."]

[Conrad - "The stuff (that is, the LM wall material) was only twenty-five thousandths (of an inch) - and, as the Sun moved slowly up, the thing oil-canned all night. You could hear it."]

[Bean - "Creaking and banging and making noises."]

[Conrad - "You could hear the structure oil-can and you could hear the pumps run; and, then, when the heat exchanger ran a little bit more or a little less, that sombitch'd change tone."]

posted 04-18-2017 01:51 PM               

Sleeping baffles me. In my mind, you’d have to have dangerously high levels of the right stuff to doze off in a tiny pressurised can on the moon. They all tell me about the alarmingly delicate skin of the lander when unpressurised — “It had a beer-can feel to it,” says Duke. When pressurised, it becomes taut and hard — but still, it’s not a very sedative thought that this paper-thin sheet was the only thing between you and the vacuum of space. Duke’s partner, John Young, had no problems on their first night, but Duke did.