...was the lava tube thing really an issue? Iirc, some wondered if people would sink into the dust...
I definitely recall concerns being expressed about the possible dangers of lava tubes prior to Apollo 11, but don't have or recall any details, and have read very little a bout it subsequently. Only Mike Collins's brief mentions in
Carrying the Fire.From a post of mine in July 2012
http://www.apollohoax.net/forum/index.php?topic=133.msg4927#msg4927I remember from the time before Apollo 11, lava tubes were still one of the great unknowns and it was thought that rilles might have been collapsed lava tubes. The surveyor craft had done a great job of sending information about the lunar surface back to earth, but being so much lighter than the LM and having widely-spaced landing pads, there was far less of a chance that they would crash through into a tube.
The only places I've seen this concern mentioned post-Apollo are in Mike Collins's book, Carrying the Fire.
On pages 339-341 is his list of 11 major hurdles during a lunar-landing trip. One of them is EVA:
7. EVA Walking on the moon might be physically taxing and overload the oxygen or cooling systems. There might be potholes, or even underground lava tubes which could cause the surface to collapse. Even more basic, any EVA puts man just one thin, glued-together, rubber membrane away from near-instant death.
And on page 410, after Houston tells Mike the crew of Tranquility Base is back inside:
Well, that's a big one behind us: no more worrying about crashing through into hidden lava tubes, or becoming exhausted, or the front door sticking open, or the little old ladies using weak glue, or any of that! Whew!
It shows how faulty our memories can become -- recently I only recalled one mention of lava tubes by Mike Collins.
Dr Thomas Gold was the person who promoted the idea that there could be very deep dust on the Moon. The 35mm 3D camera that Neil Armstrong used was named the Gold Camera after him.
Patrick Moore wrote in his book,
The Moon, Mitchell Beazley, London (1981), page 18:
...According to another theory, proposed by T. Gold in 1955, the maria were covered with dust layers kilometres deep, so that if a spacecraft were to attempt to land, it "would simply sink into the dust with all its gear"; the dust would flow downhill, accumulating in the lowest-lying areas. This theory gained a considerable degree of respectability until the successful soft landing of Luna 9 in 1966, when it was finally discarded.
Learn something new every day...
Whenever I can say that, I've had a good day. The frequency of its occurrences can diminish when Oldfartitis sets in. :-(