Alan Bean hammering core sample tube with flat side of his hammer at Halo crater
It is generally understood that there is no sound on the Moon because its atmosphere is negligible. But what if an atmosphere is brought to the Moon? That was the case with the Apollo astronauts and their space suits; a self contained atmosphere which allowed for voice communications. What is intriguing is that the sound of Alan Bean hammering on the core sample tube, which is external to his space suit, can also be heard.
The reason is that the sound vibrations were conducted into his suit with each blow of the hammer, moving on up to his helmet similar, in a way, to sound vibrations on an old style Gramophone
. The microphone in Alan Bean's helmet picked up the sound and radioed it back to Mission Control on Earth.
Old Style Gramophone- eHow.com
Here is a short audio excerpt
of Apollo 12 astronaut Alan Bean driving in the core sample tube at Sharp crater
. It is from the Bernie Scrivener
Apollo 12 audio tape recording. You can hear several short blows on the audio recording as he is hammering on the tube with the flat side of his hammer. Below is the transcript
of the audio recording from the Apollo 12 Surface Journal at Sharp Crater:
"133:02:52 Conrad: And this is core tube number 2.
133:02:54 Bean: Core tube 2 and I'll need the (extension handle to attach to the top of the core tube)...
[Recall that the extension handle has been serving as the handle for Pete's shovel. Pete is probably removing the scoop head. Later crews will have two extension handles and won't have to remove tool heads quite so often.]
133:02:56 Bean: There you go. Ought to be a good place, Pete. (Pause) In relatively fresh stuff here.
133:03:03 Conrad: Yeah; you'd better believe it. We're good.
133:03:08 Bean: Okay. In this kind of pack you could almost drive it without a hammer; but, if you'll hand it (the hammer) to me, I'll...
133:03:11 Conrad: Yeah, just a second.
133:03:14 Bean: I want to take a couple more shots (that is, photos) of this before we leave. (Pause) There. (Pause) Okay.
133:03:28 Conrad: Get it all the way in (and) I'll get the pictures.
133:03:30 Bean: All right. (The sound of hammering is audible) It's driving in real easy, Houston.
[Bean - "I didn't know that (they could hear the hammering in Houston)!"]
[Conrad - "That's neat!"]
[Bean - "Coming through my hand, I guess..."]
[Conrad - "Yeah, it's coming through your hand and getting into the air in the suit and it's transmitting all the way (to the microphones)."]
[Bean - "Isn't that something."]
[Jones - "Now, you had the Snoopy helmets on over your ears."]
[Conrad - "Yeah, but the microphones are out here (in front of their lips). I never heard that before, either. You can hear you hammering just loud and clear."]
[Bean - "I would have said it wasn't possible."]
[Conrad - "The other guy can't hear it. Did you hear yourself hammering?"]
[Bean - "I don't remember. I was so concentrated...The problem with hammering is that...Well, I'm a good carpenter, but you can't come straight down (with your arm in the suit). That's why they made the hammer bigger and everybody used the side. You can't do a nice smooth swing. You get it going (straight down) and then the cable cuts in and moves it over. So you try to adjust your swing and then you miss. Lot of missing."]
[Jones - "From watching the TV of the J-missions, what was possible was kind of a diagonal stroke across the front of your suit. But if you're driving a core tube vertically, I can't imagine that's very efficient."]
[Conrad - "It's the same thing as with the shovel. As soon as you raise your hand above the horizontal - or your arm or the hand - above the horizontal - you run into the cable and you've got to go over-center. As a matter of fact, remember guys used to have to put their arm out and go up and come back. That's how you got over the cable, which ran like a U over the top of the shoulder. (There is a good example of this motion in the Apollo 15 TV when Dave Scott goes through the motions Pete describes to reach his cooling control.) And if you want to get your arm up over your head, you didn't go straight up in front, because you'd run right smack into the cable. You went out to the side, got it over the cable, then twisted it..."]
[Bean - "You could feel the cable snap up. It was like going into an 'up' mode, and then you could lift it."]
[Conrad - "It had a definite over-center."]
133:03:34 Conrad: Going...
133:03:35 Gibson: Roger.
133:03:35 Conrad: ...(garbled) all the way.
133:03:36 Bean: I can't lean down too far now. And we're driving it all the way in pretty easy.
133:03:42 Conrad: That a boy. Wait one. Stop. That's it.
133:03:46 Bean: Okay. Just a second. Let's put this up (that is, put the hammer back on the HTC). Let me take a picture of it, Pete. Make sure we got it documented. "
In a way, Apollo 12 astronauts Pete Conrad and Alan Bean act as biological sensors during their Moon walks (EVA).
I emailed Andrew Chaikin, space journalist and author of many Apollo books with a link to the MZ Forum post and here is his reply with permission:
from Andrew Chaikin
date Sun, May 29, 2011 at 11:35 AM
subject Re: Andrew Chaikin Contact: Official NASA Documentation of Apollo 12 Hammer strikes at Sharp crater
I had heard this during my research for A Man on the Moon back in '85, and was impressed by the fact that the sound transmitted so well through the
hammer, into Alan's suit, and up to the microphone on his Snoopy cap. Thanks for the reminder and for the link to your article, and the audio
clip. I'll keep it in mind for future lectures.
Thanks again for getting in touch.