"The LM was made of aluminum foil and tape!" - counterargument

[NthBrick]

Regarding tape, pressure-sensitive adhesives can be amazingly strong.  We just don't produce them for the public for liability reasons.  We use polyamide tape with adhesives that are strong enough to hold my weight.  Engineers use tape for the same reasons non-engineers find tape convenient and appropriate.

Just to provide a bit of backstory, I interned at an engineering company for the first 7 months of this year. At that, I pretty regularly worked with materials of (to me, anyways) unexpected strength and durability. Point being, a lot of people don't realize that most materials have an "industrial" version that is far stronger and more expensive than the commercial products they're used to.

For HBs, this sort of ignorance manifests turns what could be a cool question and interesting discussion of how Apollo engineers solved a particular problem into proof of the hoax. There's rarely any desire to actually how understand how or why things were done a certain way. Hence judging the LM by its cover in the most literal sense.

[JayUtah]

Point being, a lot of people don't realize that most materials have an "industrial" version that is far stronger and more expensive than the commercial products they're used to.

And often more dangerous, which is why they aren't available to the public.  There are pressure-sensitive adhesives that will bond to skin strongly enough that it will tear the skin if you try to remove it.  This is by no means limited to "exotic" professions like engineering or high-end manufacturing.  I hired a professional janitorial company to clean one of my rental units that had seen some heavy use.  Even after I applied consumer-grade cleaning products, a large amount of soil, rust, and so forth were still present.  The crew came in and left it spotless.  How?  Because they had access to chemicals that require substantial training to use safely.  Or in other cases, the common chemicals that are sold in much higher concentrations to trained professionals.

But let's not lose Everett's point.  The parts of the LM you see -- generally the insulation blankets -- are not meant to have much if any structural robustness.  And if you saw poor LM-2 before its restoration, you'd agree.  And without an atmosphere, there was little to harm it.

[NthBrick]

Point being, a lot of people don't realize that most materials have an "industrial" version that is far stronger and more expensive than the commercial products they're used to.

And often more dangerous, which is why they aren't available to the public.  There are pressure-sensitive adhesives that will bond to skin strongly enough that it will tear the skin if you try to remove it.  This is by no means limited to "exotic" professions like engineering or high-end manufacturing.  I hired a professional janitorial company to clean one of my rental units that had seen some heavy use.  Even after I applied consumer-grade cleaning products, a large amount of soil, rust, and so forth were still present.  The crew came in and left it spotless.  How?  Because they had access to chemicals that require substantial training to use safely.  Or in other cases, the common chemicals that are sold in much higher concentrations to trained professionals.

But let's not lose Everett's point.  The parts of the LM you see -- generally the insulation blankets -- are not meant to have much if any structural robustness.  And if you saw poor LM-2 before its restoration, you'd agree.  And without an atmosphere, there was little to harm it.

Indeed on both points. What Everett is saying has basically been my response to people playing the "aluminum foil and tape" claim. When you take the design of the LM, and place it in the context of the environment that it was designed to operate in (low gravity, vacuum, needing to be light enough to make it there and take off again), it goes from awkward-looking spider-thing to a true testament to the skill of the design engineers. Understanding significantly increases appreciation.

[ka9q]

(Question - was the descent module outer thermal/micrometeorite shield a separate layer away from the structure, or was it right up against/attached to/backed by the structure? I'd assumed the former, but from the picture posed makes me wonder if it was the latter.)

According to the manuals, the thermal/micrometeroid shield was mounted on standoffs that kept it at least 0.5 inches away from the structure.

This would have formed a Whipple shield. Wikipedia has a reasonably good article on them.

[AtomicDog]

I wish writers would stop using the words "ungainly" and "awkward looking" to describe the Lunar Module. For the environment it was designed to work in, the LM was very elegant, agile, and robust.

[NthBrick]

I wish writers would stop using the words "ungainly" and "awkward looking" to describe the Lunar Module. For the environment it was designed to work in, the LM was very elegant, agile, and robust.

That it was well designed for the intended environment really is something that needs to be emphasized better. It's like why aircraft, cars, boats and submarines have different design characteristics, and none would operate well attempting to fill the place of any others.

I'm sure others have already written phenomenal pieces on the subject already, but there's a part of me that thinks researching and writing about the design of the LM with respect to the intended environment would be a lot of fun and could dispel a lot of hoax claims.

[Abaddon]

Regarding tape, pressure-sensitive adhesives can be amazingly strong.  We just don't produce them for the public for liability reasons.  We use polyamide tape with adhesives that are strong enough to hold my weight.  Engineers use tape for the same reasons non-engineers find tape convenient and appropriate.

Just to provide a bit of backstory, I interned at an engineering company for the first 7 months of this year. At that, I pretty regularly worked with materials of (to me, anyways) unexpected strength and durability. Point being, a lot of people don't realize that most materials have an "industrial" version that is far stronger and more expensive than the commercial products they're used to.

For HBs, this sort of ignorance manifests turns what could be a cool question and interesting discussion of how Apollo engineers solved a particular problem into proof of the hoax. There's rarely any desire to actually how understand how or why things were done a certain way. Hence judging the LM by its cover in the most literal sense.

Hello and welcome.

I have reason to deploy two part epoxy resin from time to time and what is fascinating (scuse pun) is how amazed people are at how such adhesives far out perform any "superglue".

The working model seems to be that if Cyanoacrylate can glue my fingers together, it can glue anything together.

Well, no. Pick the adhesive appropriate to the task at hand. Thus Kapton was appropriate for the thermal blankets. Not rocket science. Or is it?

[bobdude11]

Regarding tape, pressure-sensitive adhesives can be amazingly strong.  We just don't produce them for the public for liability reasons.  We use polyamide tape with adhesives that are strong enough to hold my weight.  Engineers use tape for the same reasons non-engineers find tape convenient and appropriate.

As Red Green always says:
 "The Handyman's' Secret Helper: Duct Tape"

[bknight]

If you can't fix it with duct tape or bailing wire, it isn't worth having.

[JayUtah]

All this is true, except (as I said) I prefer theatrical gaffer's tape as the fix-all solution.  But keep in mind that the argument was that the LM should have been a carefully designed, carefully manufactured spacecraft.  That parts of it appeared to be taped together, as one would expect from a low-cost, low-effort handyman's solution, seems suspicious to people who can see a pretty obvious parallel.

Yes, we use tape that's not like the tape you buy in hardware stores.  And yes, we use thin films.  All of these have proper engineering explanations.  Tape is better than a piercing fastener when dealing with laid-up blankets, because such a fastener would concentrate any mechanical loads on the fastener points.  That's more acceptable with more robust materials like sheet metal.  But tape is actually the best solution for mounting films in that way.  It spreads out the mechanical load.

[NthBrick]

Hello and welcome.

I have reason to deploy two part epoxy resin from time to time and what is fascinating (scuse pun) is how amazed people are at how such adhesives far out perform any "superglue".

The working model seems to be that if Cyanoacrylate can glue my fingers together, it can glue anything together.

Well, no. Pick the adhesive appropriate to the task at hand. Thus Kapton was appropriate for the thermal blankets. Not rocket science. Or is it?

Thank you, I've gotten a lot of good information lurking on this forum, and hope to contribute to some degree (though doubtless the more senior members, degreed engineers in particular, will do most of the heavy lifting).

It's funny that you bring up two-part epoxy, as I spent a lot of time working with it to make fiberglass composite parts for test aircraft. Really nasty stuff to work with, but if you're careful and diligent you can create some very sleek, strong parts. Granted, they probably wouldn't stand up to being hit with a sledge hammer, but there were light-weight and bore the loads they were designed for.

Now that I think about it, the PLSS had a fiberglass micrometeoroid cover, page 1 and paragraph 1 of the right hand column: https://www.hq.nasa.gov/alsj/LM15_Portable_Life_Support_System_ppP1-5.pdf

I'd need to do the math to get a more exact value, but I have no problem believing that a couple layers of fiberglass would provide a serious barrier to micrometeoroids. We used a 7-layer tube to contain a black powder parachute charge multiple times.

[JayUtah]

Indeed, I was focusing on pressure-sensitive adhesives since we were focusing on tape.  But if we widen the field to include all adhesives, there are some scary-strong bonds achievable with binary adhesives, light- and heat-cured adhesives, and some molecular stuff that goes beyond my knowledge of chemistry to explain.  For years and years the wing spars in Boeing airframes were laminated glue-ups.  What's that epoxy they use to bond new concrete to old?  Here in the U.S. it has a designation of the form J-<number>, but I don't recall the details.  I swear that stuff can glue smoke to air.

[Abaddon]

  I swear that stuff can glue smoke to air.

Hahaha. Brilliant.

I suspect the so-called "layman" has experience of OTC corner store adhesives and their general failings. Likely, they have not much awareness of how much of a pile of variability adhesives actually are, nor which is applicable to what task.

I find it fascinating how people think they can buy a tube of "super-glue" and it will stick anything to anything infallibly. 

[bknight]

All this is true, except (as I said) I prefer theatrical gaffer's tape as the fix-all solution.  But keep in mind that the argument was that the LM should have been a carefully designed, carefully manufactured spacecraft.  That parts of it appeared to be taped together, as one would expect from a low-cost, low-effort handyman's solution, seems suspicious to people who can see a pretty obvious parallel.

Yes, we use tape that's not like the tape you buy in hardware stores.  And yes, we use thin films.  All of these have proper engineering explanations.  Tape is better than a piercing fastener when dealing with laid-up blankets, because such a fastener would concentrate any mechanical loads on the fastener points.  That's more acceptable with more robust materials like sheet metal.  But tape is actually the best solution for mounting films in that way.  It spreads out the mechanical load.

I'm not familiar with gaffer's tape, but you work with all these kinds of tapes and if you recommend it, somebody lurking in the wings should pay attention. 

[JayUtah]

I'm not familiar with gaffer's tape, but you work with all these kinds of tapes and if you recommend it, somebody lurking in the wings should pay attention. 

I guarantee you've seen it.  It's the black cloth tape that electricians and other technicians in film and theater ("gaffers") use to tape cables down.  It actually comes in different colors, but black is by far the most common.  The substrate is a cloth duck, so it's very durable.  It can be torn with the fingers.  It's electrically insulating and able to endure quite high heat.  The adhesive releases easily from any surface, but it sticks quite well in the meantime.  The disadvantage is cost.  A large roll of high quality gaffer tape will set you back about $12.  Our theater buys it by the case, so I get a deal.

But as with duct tape and the home handyman, gaffer tape is the go-to way to temporarily repair almost anything in the film and theater world.  Gray gaffer's tape, manufactured by Shurtape, was what was carried on the Apollo missions.  Apollo 13's LiOH canister adapter was rigged using gaffer tape.