Jul 23rd, 2019

Apollo 11: Day 4

Apollo 11: This past week marked the 50th anniversary.  Doctor Aviation will post a daily blog recounting each day of the voyage.  July 19 marks Day 4, the fourth day after the launch. 

The Morning

Mission Control awakes the crew at roughly 8:30am.  Two hours later, Michael Collins reports that the astronauts are able to see a sky full of stars.  To this point in the journey, the crew saw only an occasional star and no constellations.  Ten minutes later Armstrong reports spectacular views of the moon filling ¾ of the hatch window.  Part of the moon is dark (hidden by the earth) and part is lit.  He declares, “It’s a view worth the price of the trip”

The Afternoon

The crew prepares to enter lunar orbit.  The capsule will orbit the moon multiple times before attempting a landing.  Entering the orbit is termed Lunar Orbit Insertion or LOI.  At 12:58pm, Houston reports that Apollo 11 is a go for LOI. 

At 1:13pm, the crew passes behind the moon and radio contact is lost with Mission Control.  While on the backside of the moon, the crew fires the main engine for six minutes.  This slows the craft so that it can be captured by the moon’s gravitational field.  This puts the craft into orbit between the altitudes of 61 and 169 nautical miles.

At 1:55pm, the crew gets its first view of the proposed landing area.  Armstrong reports that the pictures of the area taken by Apollo 8 and Apollo 10 are very helpful in identifying the area.  The difference between the photos and the live view is like the difference between watching a game on TV and watching it live.  The crew begins to make out the colors of gray and tan on the lunar surface.

At nearly 4:00pm, the crew begins to telecast pictures of the lunar surface.  Near dinnertime, on the backside of the moon, the crew burns the main engine of 17 seconds.  This stabilizes the orbit between 54 and 66 miles.  It also results in a complete lunar orbit every two hours.  The crew then beds down.  The longest day lies ahead.

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