50 years ago: LOI day

The Apollo 11 landing site

It’s LOI Day — Lunar Orbit Insertion  

LOI day — definitely a different feel to it, a tension in the stomach beginning to grow.

         Soon after our day officially begins, we meet the moon.

74:25 GET [time since launch]:  Pitch up 360 degrees at 0.2 degrees/sec to observe lunar surface.

               We enter the shadow of the moon

                       which slowly eclipses the sun

                            Darkness and stars suddenly appear

                               harkening to a line from “2001: A Space Odyssey,”

                                             “It’s filled with stars.”

                                    Ringed in sunlight, an arc of the surface touched by Earthshine,

                                                    the crater Tycho visible draped in earthlight,

                                                      staring out at us.       

                                       The moon takes on dimension, roundness, bellying out at its equator,

                                                reaching out to us . . .

         . . . As we ready for the burn behind the backside of the moon,

               to place us in lunar orbit.

              Behind the moon, where we’ll be out of Earthly contact

                                       It’s LOI time.

75:00  Command Module Pilot  — pre LOI 1 systems checks 

75: 25   MNVR to burn attitude

               Go/no go for LOI 1

Capcom Bruce McCandless calls from Mission Control:  Eleven, this is Houston.  You are go for LOI.

We reply:  Roger, go for LOI

Minutes later, McCandless gives the now-traditional call just before we disappear behind the moon, “We’ll see you on the other side.”

LOS — loss of signal — just eight minutes before burn time.

                     GETI (time of ignition): 75:54:28

                           No ullage

                               Burn Time:  5 min. 59.9 sec.

                                       Orbit:  59.2 X 169.8  Retrograde

                                                  Do not trim

 After 33 minutes, we emerge on the other side, back in communications.  Houston asks for our burn status report.  It’s simple — we say, “It was like — it was like perfect.”

And on the next orbit give the world a TV view of the approach to the landing site in the Sea of Tranquility. 

 We call out the landmarks along the approach route, starting over the Smyth Sea which is actually a hilly area.  This is the equivalent to 13 minutes before ignition.

We fly over the crater Webb — a landmark 6 minutes before ignition

Over the triangular- shaped Mt. Marilyn, named by Jim Lovell for his wife.  This is pretty much close to the ignition point.

Over Boot Hill which we’ll see 3 min. 15 sec. into the 12-minute descent to the surface.

The crater Maskelyne W, which will be a position check at 3 min. 39 sec. into descent, the point we will turn the lander over on its back, our windows facing up into the darkness of space so that the landing radar can lock on the surface.

We zip beyond the sinuous rille, named Sidewinder by Apollo 10.  We’re approaching the terminator now — the line between dawning day and night ahead.  You can see the shadows increase and only the sunlit side of those ridges remain illuminated.

We’ll land just after dawn, the sun behind us, so that the the long shadows bring out surface obstacles in relief.

The landing site is just barely in darkness at this time.  It’s still night in the Sea of Tranquility

For the last time untouched, night in the Sea of Tranquility.

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