Moon Landing, Apollo 11, 20th July 1969

Discussion in 'The Lounge Bar' started by CL1, Jul 13, 2019.

  1. CL1

    CL1 116th LAA and 92nd (Loyals) LAA,Royal Artillery

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  2. papiermache

    papiermache Well-Known Member

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  3. bofors

    bofors Senior Member

    I remember watching it at school on a very small black and white tv!
     
  4. papiermache

    papiermache Well-Known Member

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  5. papiermache

    papiermache Well-Known Member

    Minus 50 years, coming up today almost 24 hours after lift off: get out your sextant, chronometer and slide rule. Find the Earth horizon when not attached to the Earth.

    A recording of the radio conversation ( transcript below) can be heard here:

    https://history.nasa.gov/afj/ap11fj/05day2-mcc.html#0225015


    023:57:03 McCandless: Apollo 11, this is Houston. Over.

    023:57:08 Aldrin: Roger. Go ahead, Houston.

    023:57:16 McCandless: Roger. Mike, we've got some comments on the performance of P23 for today if you've got a minute to talk.

    023:57:20 Aldrin: He's all ears.

    023:57:22 Collins: Yeah. Go ahead.

    023:57:25 McCandless: Okay. For today, we'd like you, on P23, to make a trunnion bias determination prior to P23 sightings, as called out in the procedures, and also one afterwards. Our intent here is to check out the possibility that some sort of thermal effect may be giving you errors in the angular read-out in the sextant. The bias that you get beforehand should be incorporated, that is a Proceed on Noun 87 after you get two consecutive measurements equal to within 0.003 degrees. And, of course, move the trunnion off a couple of degrees between the measurements. The Earth should be a lot smaller in your field of view today. I'm sure you're a lot more qualified to tell us about that than we are, but to ensure that you're getting a good angle measurement between the star and the Earth horizon, the sextant M-line, which is the line that runs through the two hash marks and is perpendicular to the R-line, should be parallel to the Earth horizon at the substellar point. And then the actual superimposition of the star upon the horizon can be made at any point in the field of view of the sextant: above, below, or on the M-line. We recommend the marks be made as rapidly as possible after the Auto maneuver. If you feel that the amount of time between the Auto maneuver and the time you get ready to mark is excessive, or that you don't like that Auto maneuver attitude when you get ready to mark, of course, you can use a Verb 94 - Verb 94 to get you back to the flashing 51 position to redo the Auto maneuvers. Over. [Pause.]

    023:59:41 Collins: Roger. Stand by one. We're going to stop PTC, and then we'll talk about this P23.

    023:59:49 McCandless: Okay.
     
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