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When Neil Armstrong brought his Lunar Module, Eagle, in to land, he found that the site was strewn with boulders and had to very quickly find somewhere else to

When Neil Armstrong brought his Lunar Module, Eagle, in to land, he found that the site was strewn with boulders and had to very quickly find somewhere else to put down. I thought they overshot their intended landing site, in part because Armstrong missed some visual landmarks when his attention was taken away from the window several times by a 1202 alarm. The area beyond the site was rocky (which they knew beforehand) and by the time he located and touched down on a clear spot they had < 30 seconds of fuel remaining (leading to some clenched butts in mission control).

dmix 7y ago
What would have happened if they hit some boulders with the lander? Was there a real chance they could have been stuck on the moon?
- agildehaus 7y ago
  The walls of the LM were 0.012 inches thick. A tad under 4x the thickness of a soda can. You can imagine why hitting anything might ruin your day.
  - perl4ever 7y ago
    This raised the question, for me, of just how thick is the sheet metal on a typical earth-bound automobile. It appears that steel panels in modern cars are probably something like 0.03 or 0.04 inches thick. Aluminum panels may be 0.05" or 0.06", possibly thicker or multiple layers.
- FatalLogic 7y ago
  The lunar lander was lightweight and relatively fragile, designed for low gravity and low pressure differential. For example the aluminum alloy skin seems vulnerable to distortion and to sharp impacts, because it was 0.3mm, about 3-4x thickness of a modern soda can, though the frame supporting it was much stronger. I thought the safe take off angle was very limited, but some NASA research says that even up to 70 degrees tilt could be manageable if the crew handled it correctly. https://forum.nasaspaceflight.com/index.php?topic=32246.msg1068329#msg1068329 https://forum.nasaspaceflight.com/index.php?topic=32246.msg1... That doesn't mean 70 degrees would be safe for landing, though. Maybe it would topple or get damaged by rocket blowback. Apollo 15 was tilted about 10 degrees and that was not a problem.
- hoorayimhelping 7y ago
  Yes there was absolutely a chance they could have been stranded in the moon. Nixon had a speech prepared in case he had to tell the world Aldrin and Armstrong weren’t coming home. Ive heard the boulders described as the size of volkswagens. The lunar lander was designed to handle a small amount of tilt, but no one wanted to test it and pretty much agreed that trying to land on a boulder would cause it to tip over, definitely stranding them.
jcims 7y ago
Just a reminder that you can watch all of this at https://apolloinrealtime.org/ https://apolloinrealtime.org/
- peterburkimsher 7y ago
  The go/no-go for landing, and last few minutes before touchdown are from T= 102:42:03. There is some footage from mission control, but I could only see faces, no actual clenched butts ;)

dmix 7y ago

What would have happened if they hit some boulders with the lander? Was there a real chance they could have been stuck on the moon?

agildehaus 7y ago
The walls of the LM were 0.012 inches thick. A tad under 4x the thickness of a soda can. You can imagine why hitting anything might ruin your day.
- perl4ever 7y ago
  This raised the question, for me, of just how thick is the sheet metal on a typical earth-bound automobile. It appears that steel panels in modern cars are probably something like 0.03 or 0.04 inches thick. Aluminum panels may be 0.05" or 0.06", possibly thicker or multiple layers.
FatalLogic 7y ago
The lunar lander was lightweight and relatively fragile, designed for low gravity and low pressure differential. For example the aluminum alloy skin seems vulnerable to distortion and to sharp impacts, because it was 0.3mm, about 3-4x thickness of a modern soda can, though the frame supporting it was much stronger. I thought the safe take off angle was very limited, but some NASA research says that even up to 70 degrees tilt could be manageable if the crew handled it correctly. https://forum.nasaspaceflight.com/index.php?topic=32246.msg1068329#msg1068329 https://forum.nasaspaceflight.com/index.php?topic=32246.msg1... That doesn't mean 70 degrees would be safe for landing, though. Maybe it would topple or get damaged by rocket blowback. Apollo 15 was tilted about 10 degrees and that was not a problem.
hoorayimhelping 7y ago
Yes there was absolutely a chance they could have been stranded in the moon. Nixon had a speech prepared in case he had to tell the world Aldrin and Armstrong weren’t coming home. Ive heard the boulders described as the size of volkswagens. The lunar lander was designed to handle a small amount of tilt, but no one wanted to test it and pretty much agreed that trying to land on a boulder would cause it to tip over, definitely stranding them.

jcims 7y ago

Just a reminder that you can watch all of this at https://apolloinrealtime.org/ https://apolloinrealtime.org/

peterburkimsher 7y ago
The go/no-go for landing, and last few minutes before touchdown are from T= 102:42:03. There is some footage from mission control, but I could only see faces, no actual clenched butts ;)