Apollo 11 Timeline – 20th July 2019

Today’s that amazing day on our Apollo 50th Anniversary Timeline.
The long awaited and anticipated day when the lunar module Eagle is landed by Neil and Buzz onto the surface of The Moon in The Sea of Tranquillity.

Here’s my image of that area of The Moon, showing the landing sites of Apollo 11 (Tranquillity Base – Statio Tranquillitatis) and Rangers 5 and 8.
It also shows the three craters named after the Apollo 11 astronauts.


Follow the hectic Apollo 11 timeline on this fantastic day.

It’s too late to book tickets for my Apollo 50th celebration day today in Raunds:
Click here for more details.
You can still turn up on the day and buy a ticket.

Follow my blog here:
www.star-gazing.co.uk/blog.html

It’s an extremely busy day for Neil and Buzz as they leave Michael Collins in The Command/Service Modules (CSM) and take to the Lunar Module (LM) Eagle to take it down to land onto The Sea of Tranquillity.

12:52 – Neil and Buzz entered LM for final preparations for descent.

15:17 – LM system checks started.

17:32 – LM system checks ended.

17:44 – SM/LM undocked.

18:11 – CSM/LM separation manoeuvre ignition.

18:12 – CSM/LM separation manoeuvre cutoff.

19:08 – LM descent orbit insertion ignition (LM SPS).

19:08 – LM descent orbit insertion cutoff.

Seconds of time now being shown as time events come thick and fast during the exciting landing phase.

19:49:17 -LM acquisition of data.

19:52:53 – LM landing radar on.

19:56:40 – LM abort guidance aligned to primary guidance.

19:59:32 – LM yaw manoeuvre to obtain improved communications.

20:04:55 – LM altitude 50,000 feet.

The descent of Eagle is just about to commence.
It will take just under 13 minutes to reach the surface from 50,000 feet.

20:04:58 – LM propellant settling firing started.

20:05:05 – LM powered descent engine ignition.

The lunar module was travelling slightly too fast and was reaching landmarks a bit too early.
It seems that this was caused by them not evacuating all the air out of the tunnel between the CM and the LM before un-docking. This gave the LM a little bit of an extra push. As a result Eagle overshot the original target area.

20:05:31 – LM fixed throttle position.

20:09:59 – LM face-up manoeuvre completed.

20:10:22LM 1202 alarm.

This alarm type (and the 1201 alarm which followed) was never encountered in any of the training simulations. It was caused by the computer receiving too much information. The computer was designed to prioritise essential tasks, so the decision was made to ignore the alarm and continue the descent as the computer was still handling all the landing tasks really well.

20:10:45 – LM radar updates enabled.

20:10:50 – LM altitude less than 30,000 feet and velocity less than 2,000 feet per second (landing radar velocity update started).

20:11:02LM 1202 alarm.

20:11:31 – LM throttle recovery.

20:13:32 – LM approach phase entered.

20:13:37 – LM landing radar antenna to position 2.

20:13:53 – LM attitude hold mode selected (check of LM handling qualities).

20:14:03 – LM automatic guidance enabled.

20:14:18LM 1201 alarm.

20:14:19 – LM landing radar switched to low scale.

20:14:43LM 1202 alarm.

20:14:58LM 1202 alarm.

20:15:09 – LM landing point re-designation.

It is around this time that Neil decided to take a more manual control approach to the landing of the LM as the area where the LM was taking them down to was scattered with large boulders.

20:15:13 – LM altitude hold.

20:15:20 – LM abort guidance attitude updated.

20:15:22 – LM rate of descent landing phase entered.

20:16:11 – LM landing radar data not good.

20:16:21 – LM landing data good.

20:16:28 – LM fuel low-level quantity light.

20:16:59 – LM landing radar data not good.

20:16:35 – First evidence of surface dust disturbed by descent engine.
“PICKING UP SOME DUST” – Buzz

20:17:03 – LM landing radar data good.

CONTACT LIGHT!
These were the first words uttered from the lunar surface by Buzz, as one of the contacts below three of the LM foot-pads touched the lunar surface.

20:17:39 – LM lunar landing.

20:17:41 – LM powered descent engine cutoff.

“TRANQUILLITY BASE HERE. THE EAGLE HAS LANDED” Neil

Roger. Twank… Tranquillity, we copy on the ground. We got a bunch of guys about to turn blue. We`re breathing again. Thanks a lot. Charlie Duke – Capcom at Mission Control.

To listen to the complete landing and a fantastic explanation of exactly what went on during the landing, visit 13 minutes to The Moon, by Kevin Fong:
https://www.bbc.co.uk/programmes/w13xttx2/episodes/downloads
13 minutes to The Moon, by Kevin Fong.


As soon as they landed, they prepared everything to take off immediately.
This was in case of an emergency that may have given them any reason to escape quickly.
Astronauts and Mission Control were happy everything was go for Neil and Buzz to perform the Extra-Vehicular Activity (EVA).

22:12:00 – The decision was made to proceed with the EVA before their first rest period.
Instead of the astronauts sleeping before the EVA, as planned, they will start the EVA early.
Well, could you have slept? I couldn’t have.

23:43:00 – Preparation for the EVA started.

Neil will take his “small step” onto the moon early tomorrow morning.

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