Friday, January 28, 2011


Wallace A. Johnson MBA
Commander Spaceship DEWAJ

In the early days of Apollo studies we knew that the Lunar Landing Module would separate from the Apollo Command Module and descend to the surface of the moon with two men aboard. The Command Module would remain in orbit around the moon waiting for the return of the Lunar Landing Vehicle. One of the problems we anticipated which caused some anxiety would be the ability to make visual contact one with the other when they would rendezvous and dock. It was decided that some kind of a flashing light on both craft would take care of the matter. But that sounds a lot easier than it sounds. In the first place, was there a time restraint which had to be adhered to, ie, did we have only so many minutes to correct any miscalculations in the rendezvous such that we had to come in visual contact a soon as possible? If so, what luminosity in candle power would this light require? What color should it be? Is there a color that's better than pure white light? At what rate should this light blink? Is there a frequency that is preferable above all others? All kinds of questions come up related to finding a small object in the blackness of space. What to do?

The answer was found in a Planetarium. North American Aviation leased the facility of the Griffith Park Planetarium where we set up a mock up of the interior of the Command Module windows. We then were placed in a precise location such that we had a restricted view of the star field which was visible to us out of the windows we were looking out of. Then in the total darkness of the planetarium mixed in and hidden among the star field, a flashing light would start blinking. As a pilot subject on that study, it was my task to find the blinking star and identify its location. We had no idea what the blinking rate would be or its location in the star field. You would think it would be a easy task, but those of us who know how to search in total darkness for the slightest thing and are acquainted with what goes on with our eyes had an advantage. For we know that to get maximum capabilities from the use of our eyes at night, we know that you must never focus on the object you are looking for but rather look 10 degrees above, below, to the right, or left of the focus point. There is an explanation to this. There are two cells in the eyeball. Cones which can discern the colors of the spectrum but are not very sensitive to light and therefore of little use at night, and Rods which are color blind but very sensitive. There is only one problem, there are NO RODS in the focal point of the eyeball which is called the Fovea, only Cones are located there, and if there isn't sufficient light to activate the Cones you must rely on the Rods to pick the object up. So prove it to yourself in a real dark room, look directly at the object your are trying to see and then shift your line of vision about ten degrees and sure enough you will see the object better. If you look directly at it, it may disappear only to reappear if you look slightly off the ofject. I don't know what the data of that study proved. But I know that whatever they are currently using in blinking frequency, candle power intensity, color etc. is the result of that study. It give me a good feeling to know that I played a small part in it. To me the rhyme goes "Twinke, Twinkle Litte Star, How I wonder "Where" you are. Now you know why.

Wallace A. Johnson MBA MCEC
Apollo Project Test Pilot
Commander Spaceship DEWAJ


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