Apol­lo 11: Des­ti­na­tion Sea of Tran­quil­i­ty - First Moon land­ing

Neil Armstrong on the ‘Eagle’ lunar module
Neil Arm­strong on the ‘Ea­gle’ lu­nar mod­ule
Image 1/5, Credit: NASA

Neil Armstrong on the ‘Eagle’ lunar module

Neil Arm­strong land­ed on the sur­face of the Moon on 21 Ju­ly 1969 in the ‘Ea­gle’ lu­nar mod­ule.
Buzz Aldrin at the Sea of Tranquility
Buzz Aldrin at the Sea of Tran­quil­i­ty
Image 2/5, Credit: NASA

Buzz Aldrin at the Sea of Tranquility

In his vi­sor the re­flec­tion of Neil Arm­strong and the lu­nar mod­ule ‘Ea­gle’.
Neil Armstrong, first man on the moon
Neil Arm­strong, first man on the moon
Image 3/5, Credit: NASA

Neil Armstrong, first man on the moon

Neil Arm­strong in­side the lu­nar mod­ule 'Ea­gle' af­ter his his­tor­i­cal moon­walk. The words "That’s one small step for man, one gi­ant leap for mankind," made Neil Arm­strong fa­mous.
Apollo 11: The Eagle lunar module on the moon
Apol­lo 11: The Ea­gle lu­nar mod­ule on the moon
Image 4/5, Credit: NASA

Apollo 11: The Eagle lunar module on the moon

Neil Arm­strong and Buzz Aldrin spent ap­prox­i­mate­ly two-and-a-half hours on the lu­nar sur­face. The as­tro­nauts’ de­par­ture, their route and ra­dio com­mu­ni­ca­tions with the con­trol cen­tre in Hous­ton were broad­cast live on Earth. Over 600 mil­lion peo­ple wit­nessed the first steps on the Moon. First, Arm­strong took a soil sam­ple and stowed it in his space­suit so that in case of an emer­gen­cy and an im­me­di­ate re­turn to the Com­mand Mod­ule, he would be able to bring some Moon ma­te­ri­al back with him for the sci­en­tists on Earth. The as­tro­nauts then as­sem­bled ex­per­i­men­tal equip­ment stored in the Ea­gle’s pay­load bay, and, of course, the US flag was plant­ed in the lu­nar soil.
Tracks on the Moon
Tracks on the Moon
Image 5/5, Credit: NASA, Scan: JSC

Tracks on the Moon

Buzz Aldrin’s foot­print on the Moon. He want­ed to doc­u­ment the char­ac­ter­is­tic lu­nar dust, which is as fine as pow­der.

Crew and spacecraft

As early as 1965, definite plans were being drawn up for Apollo 11, the first ’G-Mission’ in the Apollo program. Its objective was to be the first to land a man on the Moon – even “before this decade is out”, as called for by President John F. Kennedy before his assassination in 1963, “and return him safely to Earth”. It was not until 1967 that the decision became generally accepted to allow not one but two of the astronauts to disembark from the lunar module onto the surface of the Moon. In January 1969, NASA announced the names of the three astronauts with whom the first Moon landing was to take place. The crew was selected on the rotation principle that had been applied up to that time in the Apollo program. The reserve crew of a preceding flight had to wait for two further flights before themselves being assigned for a flight. This meant that the backup crew for Apollo 8 – Neil Armstrong, Edwin ‘Buzz’ Aldrin and Fred Haise – would make up the crew for Apollo 11. Neil Armstrong, the Apollo 11 Commander, was however able to get Michael Collins selected in place of Haise because Collins had lost his place in the Apollo 8 backup crew on account of a medical condition. Neil Armstrong came from Ohio and was 39 years old when the mission began. Before entering his career as an astronaut, he worked as a naval aviator and civilian test pilot. He died on August 25, 2012. Buzz Aldrin was the same age, came from New Jersey, served in the armed forces, and had been stationed for a while in Germany. He received a Ph.D. in astronautics with a thesis on guidance techniques for manned orbital rendezvous. This led to his being given the nickname ‘Dr. Rendezvous’. Michael Collins, too, was born in 1930 and flew US Air Force fighter jets before becoming an astronaut.

The configuration of launch vehicle and spacecraft was almost identical to that of Apollo 10. The Saturn V build for the launch had the serial number AS-506. The command module was named ‘Columbia’ and the lunar module was given the name ‘Eagle’, the American heraldry animal. The eagle shown in the mission emblem has an olive branch in its claws to show that the USA was flying on a peaceful mission to the Moon. Originally, to save weight, NASA did not want to include any scientific experiments on the first Moon landing. Following the advice of the consulting scientists, however, NASA did prepare a small set of instruments known as EASEP (Early Apollo Scientific Experiment Package).

Mission progress

On April 14, 1969, the rocket, spacecraft and lunar module had all been put together and the Saturn V was in place on its launch pad in Cape Canaveral and ready for lift-off on June 6. Fully fuelled, the rocket weighed nearly three thousand tons. All in all, including the fuel for flight maneuvers on the way to the Moon, for the Moon landing and for return to Earth, Apollo 11 weighed more than 43 tons. Today, there are no longer any launch vehicles that could carry such a load and take it from Earth into space.

On July 16, 1969 at 9:32 local time, Apollo 11 was launched under optimum weather conditions. Twelve minutes later, it had reached the Earth parking orbit. After one-and-a-half orbits, the third stage fired to put the spacecraft on its way to the Moon. After several hours, the lunar module was docked onto the command module. The mission reached the Moon without a problem on July 19. The engines were fired to insert the spacecraft into lunar orbit. On July 20, Armstrong and Aldrin boarded the lunar module, carried out tests, undocked the lunar module from the command module and began their descent to the Moon.

The astronauts noticed that they had passed by the orientation points on the lunar surface about 6 seconds ahead of time and knew therefore that they would fly past the targeted landing site. Five minutes after separation and 1800 meters above the surface, there was a first so-called ‘1202 program alarm’ because the on-board computer was no longer able to process the massive amount of measured data. When Armstrong saw that the programmed flight route would take them to a dangerous landing point in a crater containing a vast number of rocks and boulders, he changed over to semi-automatic manual control, flew past the crater and landed the lunar module on a level surface at 21:17:40 CET – with just enough fuel left for another 45 seconds. Astronaut Charlie Duke was responsible at Mission Control for radio communications and waited for a sign of life. After shutting off the engines, Armstrong radioed immediately to Earth: “Houston, Tranquillity Base here. The Eagle has landed”. After a few seconds, the reply came: “Roger, Tranquillity, we copy you on the ground. You’ve got a bunch of guys about to turn blue. We’re breathing again! Thanks a lot!”

On the Moon

The landing site was to be on the western side of the Oceanus Procellarum, the ‘Sea of Tranquillity’, near the Moon’s equator. NASA had selected this site because it was a broad, dry plain. The eastern part of the lunar near side appeared more favorable because the Sun (as seen from Earth) would rise there earlier: a favorable factor for the mission. Also, with the Sun lying low behind the astronauts, they would be able to see better when approaching the landing site. After landing, Neil Armstrong and Buzz Aldrin first made all the necessary preparations for an emergency lift-off just in case the mission had to be aborted. A rendezvous with the spacecraft piloted by Michael Collins in lunar orbit would have been possible every two hours. Armstrong and Aldrin then described what they saw around the lunar module from the small window. Finally, Neil Armstrong opened the hatch six and a half hours after landing.

In the USA it was still evening on July 20, in Germany it was already July 21. An outside camera filmed the historic event that was transmitted live to Earth and to all nations. Armstrong climbed down the steps of the ladder. At 3:56 and 20 seconds CET, the first man stepped from the foot pad to set foot on the Moon and spoke the unforgettable words: “That‘s one small step for man, one giant leap for mankind.”

Buzz Aldrin followed 18 minutes later. From the outset, small rocks were gathered. Then a frame was put up with aluminum foil to collect energetic particles of the solar wind to take back to Earth. A flag of the United States of America was stuck into the lunar ground. A seismometer was put into place to measure moonquakes, experiments for investigating the nature of the lunar soil, and a laser reflector that remained on the lunar surface in order to measure the distance between Earth and Moon. During the nearly two-and-a-half hours that the astronauts spent outside of the lunar module, they collected 21 kilograms of dust and rock samples. After 21 hours and 36 minutes on the Moon, they commenced their return to ‘Columbia’ without a hitch. Having docked onto the spacecraft, they flew back to Earth. The command module splashed down safely on July 24, 1969, in the Pacific Ocean.


The most significant result of the first lunar landing was the fact that it had been possible to “landing a man on the Moon and return him safely to the Earth” within less than the decade that John F. Kennedy had called for. The incredibly successful Apollo project accomplished by engineers and scientists is one of the greatest achievements in the history of mankind. In the days of the Cold War, with the strong competition between the political systems of the West and the Soviet Union, this accomplishment of NASA was interpreted above all as a political triumph. Apollo 11 meant that the USA had not only established firm leadership in space technology, they had also proven their dominance in many technical developments. In the long term, Apollo also had a philosophic dimension. For the first time, man had been able to step foot on another celestial body. The cost of the entire Apollo program was gigantic – the official figure was 23.4 billion dollars. Apollo produced the long term effect of enabling the USA to profit through an improvement in engineering and scientific education and training. Initially, it was not quite clear just what new scientific knowledge had been gained.

But even the short stay of Apollo 11 on the Moon opened a door to entirely new knowledge of the solar system. For the first time, rock samples of known origin were taken from other heavenly bodies. Up until then, the only extraterrestrial material available was in the form of meteorites. An analysis of the rocks showed that the Moon and the Earth were very old – roughly four-and-a-half billion years old.

The most important finding was that the Moon was not formed ‘cold’ but ‘hot’, that is it was initially covered by a hot magma ocean of molten rock and that the same must also apply to the Earth. Apollo 11 landed on a plane made up of basalt, a low-viscosity volcanic material that is frequently found on Earth. At the same time, samples baked together from small rock rubble show that innumerable impacts of many small objects in the solar system have changed the surface of the Moon and given it its present-day appearance. It soon became fairly clear that there was no life and no organisms on the Moon. Nonetheless, to make quite sure, the three American heroes were put in a container and subjected to strict quarantine for 17 days. The result was negative.

The texts presented here were created by the DLR Institute of Planetary Research and space expert Gerhard Daum for the exhibition ‘Apollo and Beyond’ at the Technik Museum Speyer. Among other things, the history of the Apollo programme is showcased in detail using both text and images. In addition, full-scale models of the Apollo 11 Lunar Module ‘Eagle’, the Apollo 15 Lunar Roving Vehicle and an Apollo space suit for visiting the Moon’s surface, as well as a 3.4-billion-year-old rock collected from the Apollo 15 landing site can be seen in a lunar landscape.

  • Ulrich Köhler
    Ger­man Aerospace Cen­ter (DLR)
    In­sti­tute of Plan­e­tary Re­search
    Rutherfordstraße 2
    12489 Berlin
  • Elke Heinemann
    Ger­man Aerospace Cen­ter (DLR)

    Com­mu­ni­ca­tions and Me­dia Re­la­tions
    Telephone: +49 2203 601-2867
    Linder Höhe
    51147 Cologne
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