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The Apollo lunar module had thin skins of foil for protection / air containment. What would have happened if a hole was made in this skin by a flailing astronaut, screwdriver, asteroid, etc.? Would the tear have gotten larger and larger before it could be patched?

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    $\begingroup$ The thin skins of foil on the outside of the craft were not there to maintain air pressure, they are used (even on modern spacecraft) to insulate it from thermal radiation. As aramis mentioned, the pressure hull was 0.3mm thick which would be practically impossible for an astronaut to puncture accidentally, a concerted effort with a hammer and sharp instrument (e.g. screwdriver) would be needed to punch a hole in it from inside. However, a micrometeoroid would punch straight through that thickness of aluminium from outside. $\endgroup$ – squigbobble Dec 18 '15 at 12:07
  • $\begingroup$ The foil on the outside was mylar, with a micro-thin layer of gold, not aluminum, too. madsci.org/posts/archives/2001-07/994536402.Es.r.html $\endgroup$ – aramis May 2 '16 at 10:36
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A hole in the LEM during lunar operations would likely have been grounds to abort, and return to the CSM. For the flight up, it's known that duct tape was carried in the LEM; Apollo 17 made use of it repairing their rover, and proved it's ability to hold in high quality vacuum. It's thus very likely that they'd have patched a single small hole or pair of small holes with duct tape from the inside, and checked for pressure. It's almost certain such a repair would still have them make the trip in suit, ready to button up immediately.

A hole in the CSM might be more of an issue, since large portions of the pressure vessel are inaccessible during flight. If such an inacessible hole happened, it's likely the crew would have gone to suits, on umbilicals, and taken the very next opportunity to aim for Earth. An accessible hole would have been patched with duct tape or better materials.

Further note: the Apollo astronauts had a suit repair kit; it would likely have been used in the case of a breach.

Discussion

Keep in mind: the wall thickness was 0.012 inches (≅0.305mm); this is about 3.8x the thickness of a typical soda can (≤0.1mm), and those are not easily holed (it tends to deform rather than puncture). Further, the internal pressure makes the skin rigid, just like a soda can; a can of 7-up is 30psi, and a standard atmosphere about 14.7 - so a soda can is thick enough to hold in 1 atmosphere. The walls of the LEM are three to four times thicker... thus harder to pierce, and less likely to tear if punctured.

References

Moondust and Duct Tape (http://science1.nasa.gov/science-news/science-at-nasa/2008/21apr_ducttape/). Retrieved 2 Aug 2013.

Events, exhibits 40 years after man on moon (http://www.today.com/id/31923804/ns/today-today_travel/t/events-exhibits-years-after-man-moon/#.Uft6EGTwKzo) Retrieved 2 Aug 2013.

The Saturn/Apollo Stack - Lunar Module (http://h2g2.com/approved_entry/A3770192) Retrieved 2 Aug 2013.

The Canmaker Frequently Asked Questions (http://www.canmaker.com/news/index.php?option=com_content&view=article&id=1504&Itemid=126) Retrieved 2 Aug 2013.

Pressure in a Can of Soda (http://hypertextbook.com/facts/2000/SeemaMeraj.shtml) Retrieved 2 Aug 2013.

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