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Apollo 11 Earth Orbit Map

Updated: May 24, 2020

Most places are visited before they are mapped. But not the moon. Many maps of the moon already existed before J.F. Kennedy in 1961 declared putting a man on the moon one of the prime goals of the United States:

"I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish."

Although it is often stated that the main goal of this expensive and dangerous mission was rivalry with the Russians, Kennedy initially proposed the Russian to make it a joined project. But they refused. And by July 1969, the NASA had reached the point where all was ready for sending a manned spacecraft to the moon.

This map is the Apollo Earth Orbit Chart for July 1969 launch dates. It is the second map from a set of three. This maps shows the projected trajectory of the 2nd earth orbit after launch.

The map was released in June by NASA and shows the trajectories that would be followed depending on the launch date and launch azimuth (which is a factor of launch time). For July, these dates were the 16th, 18th or 21st. The launch windows were dependent of the lunar phase, the optimal launch azimuth to take maximum advantage of the earth's rotation in achieving orbital velocity, and other technical reasons.

The map shows the projected flight path in blue. Flight paths are shown for launch azimuths between 72° and 108°. This range was chosen in order to keep the rocket after launch within the so-called Eastern Test Range: An over-see area starting at the launch pads at Cape Canaveral Air Force Station and Kennedy Space Center and extends eastward over the Atlantic Ocean. This area is relatively free from world shipping lanes and inhabited land masses, and was monitored extensively.

Except for the flight paths, many other features are shown. The areas surround by black lines show the areas covered by one of the ground tracking stations. These stations NASA used several networks of ground-based antennas were used to track and communicate with the Earth orbiting spacecraft.

Here, the two ground stations in Australia are shown: Carnarvon Tracking Station (CRO), and Honeysuckle Creek (HSK). As can be observed, the areas covered by these stations are no perfect circles. This is caused by local geographical factors, such as mountains, and by technical properties of the antenna.

Apollo 11 was launched on July 16th, at 9:32:00 am EDT, launch azimuth 72.058°, so it follows the most southern blue trajectory. If we track the trajectory, we come across three overlapping red-lined circles. These indicate the areas covered by ships equipped to track and communicate with the spacecraft: Injection Ships 1 and 2, and the USNS Huntsville (HTV). These ships were brought in position to monitor and direct one of the most important procedures during the initial phase of the missing: Trans Lunar Injection (TLI): When the second ignition of the S-IVB engine pushes the spacecraft onto its trajectory towards the Moon.

The moment was carefully chosen. To arrive near the moon the spacecraft had to be targeted at a position where the moon would be when the spacecraft arrived. The moment of TLI shown on this sheet was the first opportunity to exit earths orbit. Sheet 3 marks a second opportunity. But that would no be needed.

The almost horizon red line marked TLI (16 JULY) marks the moment from when the 'burn' had to be initiated, and the black line TLT (16 JULY) marks the moment when the 'burn' had to be terminated, and leaving earths orbit would occur.

At 16:22:13 UTC, at 9.9204°N, 164.8373°W, Trans Lunar Injection was performed. Apollo 11 had left its orbit of the earth, and was on its way to the moon. And the rest is history.



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