People on the Moon

People have looked up at the Moon for as long as they have existed. They attributed wondrous powers to it; it was worshipped and feared. There are many songs and stories about it. Most were created at a time when little was known about the Moon.

You could observe it through telescopes and actually make out a few things from a great distance. But the Moon always seemed out of reach. Until 20 July 1969. On that day, people landed on the Moon for the first time. It was therefore a special day for all of us. In Europe, 21 July had already begun.

The first people to set foot on the Moon were American astronauts Neil Armstrong and Edwin Aldrin. Their journey to the Moon was dangerous, exciting and successful. After them, only 10 more people have set foot on the Moon. They brought 384 kg of Moon rock back to Earth, along with many scientific discoveries. Since then, we have learned much more about the Moon, Earth and ourselves.

In the 1960s, the former Soviet Union and the United States of America raced to reach the Moon. President Kennedy had set the goal of landing people on the Moon and bringing them safely back to Earth. In December 1968, three American astronauts were sent to the Moon by rocket for the first time. They orbited it and were the first people to see its far side. But a landing was not planned until July 1969. For this mission, NASA selected astronauts Neil Armstrong, Edwin Aldrin and Michael Collins. Their spaceflight was called "APOLLO 11". The picture below shows Neil Armstrong on the left, who eventually became the first person to set foot on the Moon. Edwin Aldrin is on the right; he landed on the Moon with Armstrong. Michael Collins is in the middle. He orbited the Moon in the spacecraft "Columbia" while Armstrong and Aldrin carried out the landing in the lunar module "Eagle".

It took a great deal of effort to take two people to the Moon and bring them back. The Americans developed a huge rocket for this purpose, of which only a few were built. It was called “SATURN V”. It stood 110.6 m tall. At launch, the “Saturn V” weighed 2,900 tonnes, and the fuel alone weighed 2,550 tonnes. This rocket had five enormous engines and three stages. All the Moon missions launched from Cape Kennedy in Florida. Once the fuel in a stage had burned up, that stage was jettisoned.

The rocket’s third stage finally accelerated the spacecraft, with the astronauts on board, to a speed of 28,000 km/h. This speed is needed for a spacecraft to reach orbit around Earth. After the spacecraft had circled Earth one and a half times, the third stage was fired again. The spacecraft was then accelerated to a speed of 39,000 km/h. The rocket engines burned for a total of just 16 minutes. It then took 60 hours for the spacecraft to reach orbit around the Moon.

Every celestial body—including Earth and the Moon—attracts everything around it. We call this force gravity. To overcome Earth’s gravity, a spacecraft must accelerate to a speed of 39,000 km/h.   On its way to the Moon, it then gradually slows down. Its speed only increases again once it enters the Moon’s gravitational field. During the Apollo 11 flight, the third stage of the “Saturn” rocket was jettisoned first. Only the “Columbia” command module and the “Eagle” lunar module continued on to the Moon. After the spacecraft reached its destination, its engine slowed it down and it entered orbit around the Moon.

After reaching orbit around the Moon, astronauts Armstrong and Aldrin climbed into the lunar module “Eagle”. Once they had transferred, “Eagle” separated from “Columbia”. Collins stayed behind alone in it. Only Armstrong and Aldrin floated down towards the Moon’s surface. They had chosen the “Mare Tranquilitatis” as their landing site. There are no mountains and only a few craters in this “Sea of Tranquility”, and the Moon’s surface is quite flat there. The lunar module touched down on 20 July 1969, at exactly 21:17 European time. It nearly landed in a crater. If it had tipped over, the men would never have been able to leave the Moon. But everything went well. “Eagle” landed safely on its long legs. The astronauts took a short break and ate something. Then they put on their spacesuits. At 3:40, Neil Armstrong opened the outer hatch and climbed down a ladder. As he set foot on the Moon, he said: “That’s one small step for a man, one giant leap for mankind.”

The two astronauts worked outside the lunar module for just over two hours. They raised the flag of the United States of America and set up some instruments. They also collected some moon rocks. This was followed by an eight-hour rest inside the "Eagle". Then came another immensely exciting part of the flight: the return to the "Columbia". The lower part of the lunar module remained on the moon. It served as a launch platform. The engine was fired. It had to accelerate the upper part of the module to a speed of 6643 km/h so that it could enter orbit around the moon again. The manoeuvre was successful. The "Eagle" docked safely with the "Columbia". A few hours later, the astronauts detached the "Eagle" from the "Columbia" again. The module was no longer needed and was launched into orbit around the sun. The "Columbia", however, fired its main engine and began its journey back to Earth.

The next day, the rear section of the “Columbia” was detached. Only the command module itself was to land safely on Earth. It approached at great speed. The capsule had to enter Earth’s atmosphere at a specific angle. This generated intense heat through friction. If the angle had been too steep, the capsule would have overheated and burned up. If the angle had been too shallow, the capsule might have bounced off the atmosphere and been flung back into space. But everything went well. The capsule eventually landed in the Pacific Ocean. For the final few kilometres, it descended towards the water by parachute. The astronauts initially had to wear protective suits again because there were fears they might have brought germs back from the Moon. But that was not the case. The “Apollo 11” mission ended with the three brave men’s safe and successful return home.

Six more crewed missions to the Moon followed "Apollo 11". The "Apollo 13" mission nearly ended in disaster. On the way to the Moon, an explosion occurred aboard the spacecraft. It could no longer be steered properly. The Moon's gravity was used to put the spacecraft back on a course towards Earth. The three astronauts of "Apollo 13" also returned safely to Earth, but without having set foot on the Moon. The "Apollo 17" mission marked the end of crewed flights to the Moon for the time being in December 1972. All the missions were successful except "Apollo 13". So far, 12 people have set foot on the Moon. Some of the astronauts even drove around on the lunar surface in a "Moon buggy". It was powered by an electric motor and reached a speed of 18 km/h. More missions were planned, but were cancelled because each flight cost a great deal of money. Since then, people have tried to explore the Moon with simpler probes and instruments. Some equipment and many footprints were left on its surface. Because there is no weathering, they can still be seen today. You can look it up …