Sandblasting Surveyor III

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Sketch completed 17 March 2004
Drawing Copyright by Ulrich Lotzmann. All rights reserved.
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Ulli writes "This is my first sketch using ink, watercolor and crayon. Although it's a fantasy sketch, I think it's characteristic of the unique Apollo 12 spirit."


The following extract is from NASA SP-284 "Analysis of Surveyor 3 materials and photographs returned by Apollo 12" (page 161):

"During the 31 months that Surveyor 3 was on the Moon, the white surface of the camera was discolored; in the final stages of LM landing, lunar dust was accelerated by the LM exhaust. This dust literally sandblasted the Surveyor spacecraft, removing much of the discoloration, except in areas that were shielded. The sharpness of the shadows created by the shielding indicates that the path of the lunar dust was only slightly curved by lunar gravity, indicating the lunar dust was traveling in excess of 100m/sec."
And the following is from the Apollo 12 Landing chapter of the ALSJ.
110:31:06 Bean: Oh! Look at that crater; right where it's supposed to be! Hey; you're beautiful. Ten percent (fuel remaining). 257 feet, coming down at 5; 240 coming down at 5. Hey, you're really maneuvering around.

110:31:19 Conrad: Yeah.

110:31:21 Bean: Come on down, Pete.

110:31:22 Conrad: Okay.

[Pete is descending very slowly as he flies along the north rim of Surveyor Crater, looking for a good spot to land.]

[Conrad, from the 1969 Technical Debrief - "I had the horizontal velocity under control about the time I passed the near (eastern) edge of the Surveyor crater (at about 110:31:00). I saw a suitable landing area between the Surveyor crater and Head Crater, which meant I had to maneuver to my left and sort of fly around the side of the crater, which I started to do. I guess I wheeled her around it pretty hard, because Al commented a couple of times that I was really cranking her around; and I told him it was no problem."]

110:31:23 Bean: Ten percent fuel. 200 feet; coming down at 3. (You) need to come on down.

110:31:29 Conrad: Okay.

110:31:31 Bean: 190 feet. Come on down. 180 feet; 9 percent (fuel remaining). You're looking good. Going to get some dust before long. 130 feet; 124 feet, Pete. 120 feet, coming down at 6. You got 9 percent, 8 percent. You're looking okay. 96 feet, coming down at 6. Slow down the descent rate! 80 feet. 80 feet, coming down at 4. You're looking good. 70 feet; looking real good. 63 feet. 60 feet, coming down at 3.

110:32:04 Bean: 50 feet, coming down; watch for the dust.

110:32:06 Conrad: Yeah.

[Conrad, from the 1969 Technical Debrief - "As soon as I got the vehicle stopped in horizontal velocity at 300 feet (figure 4-12 from the Apollo 12 Mission Report indicates that he stopped almost all of his forward motion at about 220 feet), we picked up a tremendous amount of dust - much more than I had expected. It looked a lot worse than it did in the movies I saw of Neil's landing. It seemed to me that we got the dust much higher than Neil indicated. It could be because we were in a hover, higher up, coming down. I don't know. But we had dust from - I think I called it around 300 feet. I could see the boulders through the dust, but the dust went as far as I could see in any direction and completely obliterated craters and anything else. All I knew was (that) there was ground underneath that dust. I had no problem with the dust, determining horizontal (fore and aft) and lateral (left and right) velocities, but I couldn't tell what was underneath me. I knew I was in a generally good area and I was just going to have to bite the bullet and land, because I couldn't tell whether there was a crater down there or not."]

[Pete does not want to land with one or two legs in a crater large enough to give the spacecraft a significant tilt.]

110:32:07 Bean: 46 (feet).

110:32:09 Carr: Low level (5.6 percent fuel remaining).

110:32:10 Bean: 42 feet. Coming down at 3. Coming down at 2. (Acknowledging Carr's warning) Okay. Start the clock. 42 feet, coming down at 2. 40, coming down at 2. Looking good; watch the dust. 31, 32, 30 feet. Coming down at 2, Pete; you got plenty of gas, plenty of gas, babe. Hang in there.

[Conrad, from the 1969 Technical Debrief - "At that point, the dust was bad enough and I could obtain absolutely no attitude reference by looking at the horizon and the LM. I had to use the 8-ball. I had attitude excursions in pitch of plus 10 (degrees) and minus 10, which happened while I was looking out the window making sure that the lateral and horizontal velocities were still nulled."]
110:32:28 Carr: 30 seconds (of fuel remaining).

110:32:29 Bean: 18 feet, coming down at 2. He's got it made! Come on in there. 24 feet.

110:32:35 Bean: Contact Light.

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