Was Apollo 11 aligned with Surveyor 5

History of space travel


Chapter 1: Our Solar System

Chapter 2: The Sun
Mercury - crater-strewn planet
Venus - huge greenhouse
Earth - the blue planet
Our moon
Mars - red neighbor
History of space travel
Jupiter - The largest plane t
The moon Io
Saturn - Ringed Giant
The Saturn moon Titan
Uranus - One ocean
Neptune - ice blue planet
Pluto - Distant dwarf

Chapter 3: Space
The history of space travel
First steps into space
On the way to the moon
Bases in space
Exploring the solar system
The future of space exploration
Apollo 13 - the unfortunate flight
Apollo missions at a glance
Pioneer - ambassador in space
Message from the Pioneer probes
Voyager Tour to the Outer Planets
Planet tour by Voyager
Voyager mission in interstellar space
Galileo in orbit of Jupiter
Pathfinder - Exploration on Wheels
Alpha - The international space station
Structure of the station
Data from the Alpha space station
Space travel time table

Chapter 4: Appendix


Internet addresses


Space - infinite expanses ...

It has always been a great dream of man to explore these infinite expanses and the origin of the universe.

As in the 16./17. Century Galileo Galilei, Nicolaus Copernicus or Johannes Keppler, scientists still strive to expand our knowledge of our universe. If it used to be the Catholic Church, today it is the lack of interest of the population and the resulting cuts in funding that hinder the work of astronomers. The aim of this project work is to re-awaken interest in astronomy and space research by imparting a basic knowledge of our solar system and the history of space travel. This should be a contribution to making people aware of the natural sciences, so that in the future too, areas of space can be explored where no one has been, where no one has ever been before.

Chapter 1: Our Solar System

Chapter 2: The Sun

The sun is the largest and most massive body in the solar system. It has a diameter of 1.4 million kilometers and is 109 times the size of the earth. In addition, their mass is 330,000 times greater than that of Earth.

The temperature of the solar center is 14 million degrees. This energy is generated by nuclear fusion, in which hydrogen nuclei fuse to form helium nuclei. The sun is about 5 billion years old and will continue to shine for at least the same time.

The temperature on the sun's surface is 5,5000 C. This lowest layer of the atmosphere is known as the photosphere. It extends to an altitude of 300 km. Gas bubbles rising from the interior of the sun give the photosphere a granular structure known as granulation. The individual granules have a diameter of 1000 to 2000 km. The photosphere is very active and so changes in the magnetic field create black spots. These sunspots are 1,5000 C cooler and exist for 11 years.

Above the photosphere is the chromosphere at an altitude of 10,000 km. It consists of thin gases so that it cannot be seen. Magnetic field fluctuations in the chromosphere create protuberances in which luminous plasma is thrown into the corona.

This is the outermost layer of the sun's atmosphere, which extends far into interstellar space. It is hot up to 3 million degrees. It was only recently discovered why the corona is much hotter than the photosphere. With the research probe SOHO (Solar and Heliospheric Observatory) it was discovered that a barrage of magnetic short circuits heats the corona. These consist of up to 2,800 lightning thunderstorms per second and sometimes last several minutes.

In the process, individual gas bubbles are heated to up to 1 billion degrees Celsius. These are distributed in the corona and cool down again in a quarter of an hour.

Mercury - crater-strewn planet

Mercury is the planet closest to the sun in this solar system. It orbits the sun every 88 days and revolves around itself every 58.6 days. This two-to-three ratio of orbital and rotation time leads to the phenomenon that the sun moves back and forth.

Since the orbit of Mercury is very elliptical, this leads to very large temperature fluctuations. The temperatures rise to 420 during the day0 C and fall to -170 at night, as Mercury does not have an atmosphere to hold the heat0 C.

During its orbit, Mercury is 46-70 million km from the Sun. Mercury is difficult to observe from the earth because it is located between the earth and the sun for most of the time. Therefore, most of the knowledge about Mercury was obtained from the Mariner 10 probe, which flew 3 times to the planet in 1974/75. Unfortunately, she was only able to map half of Mercury due to poor lighting conditions.

Nevertheless, one received extensive knowledge of the planet. So it looks very similar to the moon and like it is covered with craters. However, compared to the moon, it lacks the great seas.

The most important event on Mercury was probably the collision with a huge meteorite, the impact of which formed the Caloris Planitia basin. It has a diameter of 1300 km and the earthquake caused by the meteorite even left changes on the opposite side of the planet.

Another peculiarity that only exists on Mercury is a system of long furrows that are 500 to 1000 m high and several hundreds of kilometers long. They were caused by movements of the bark when the interior of the planet was heated or cooled, or by gravitational effects of the sun.

Venus - huge greenhouse

Venus is a very inhospitable planet, although it is very similar to Earth in terms of mass, size and density. The atmosphere is 100 times denser than on earth and consists of 90% carbon dioxide. This creates a greenhouse effect that puts the planet on 4200 C heated. At a height of 70-90 kilometers there are ice crystal clouds, the only place where there is water on this planet. These clouds prevent observation with normal telescopes, so that the planet can only be observed with probes such as Pioneer Venus Orbiter or with radar. Underneath, at an altitude of 56.6-70 kilometers, is a layer of yellow clouds that are mainly composed of sulfuric acid. Since Venus needs 243 Earth days to complete one revolution, the sulfur clouds are heated so much that they move at three times the speed of a hurricane.

It is remarkably calm on the planet's surface as the storms take place in the upper atmospheric layers. The atmosphere is also a little clearer, so that you can see up to 3 kilometers away. Although the gravitational pull of the planet is less than that of Earth, you can only move around using swimming movements. The reason for this is that the clouds in the upper atmosphere compress the lower layers so much that the pressure on the surface is as high as 500 meters below the sea.

Overall, Venus is a very smooth planet. 65% of the surface consists of slightly undulating areas, so-called "rolling planes". However, there are also mountains that are higher than Mount Everest, such as Maxwell Montes with a height of 10.6 kilometers.

Radar observations from Earth and measurement results from the Venera 15 and 16 probes showed that there are also numerous volcanoes on Venus. Additional rock analyzes of the probes Venera 9, 10, 13 and 14 led the researchers to the conclusion that Venus is still a geologically very active planet and that the process of surface formation is not yet complete.

Earth - the blue planet

So far, the earth is the only known place where life is known to exist.

Its mean distance from the sun is 149.6 million kilometers and it takes 365.25 days to complete one orbit. It has a diameter of 12,756 km and a mass of approx. 6 trillion tons, resulting in an average density of 5.52 g / cm3 results. It has a rotation time of 23 hours 56 minutes and 4.09 seconds. The equator is inclined 23.5 degrees from the plane of the orbit, which is known as the ecliptic, from which the seasons result. About 4 million years ago life arose in the earth's oceans, which cover 71% of the surface.

An important prerequisite for the creation of life was the earth's magnetic field, which kept high-energy radiation away from the earth. However, this magnetosphere is deformed by the solar wind, consisting of electrically charged particles from the sun. This can be seen in the accompanying drawing. The point where the solar wind and the magnetosphere meet is called Shock front (1). Behind is the Magnetopause (2), the boundary zone of the magnetic field. (3) is the danger zone for space travelers because the electrically charged particles can damage DNA, which in turn can lead to cancer. When there is increased solar activity, so-called polar lights can arise, or sometimes electromagnetic storms that can even damage or destroy satellites.

Our moon

The moon is the easiest celestial body to observe as it is only 384,400 km from Earth. It has a diameter of 3,476 km and weighs only 1/81 as much as the earth. Due to the low gravity, a body is only 1/6 as heavy as on earth. When observing the moon, one discovers dark spots that are seas (Maria) acts. It is also noticeable that the moon is only ever seen from the same side, which is due to the interaction of the gravitational forces of the earth and moon.

There is no atmosphere on the moon. Therefore he is defenseless at the mercy of the sun, which means that it is on the illuminated side 1200 C gets hot with -150 on the other side0 C is cold.

The moon received its first visit on September 13, 1959, when the Luna 2 probe struck between the Archimedis and Autolycus craters. On February 3, 1966, Luna 9 made its first soft landing on the western edge of the Ocean of Storms. And on July 21, 1969, Neil Armstrong and Edwin Aldrin were the first people to land on the moon.

Mars - red neighbor

Mars is the most Earth-like planet in our solar system. This is why Mars is the planet most likely to be alive. It's half the size of Earth, and a day on Mars is roughly the same as a day on Earth. Like the earth, Mars also has different seasons, which are, however, twice as long. Although it has a very thin atmosphere, which consists of 95% carbon dioxide and 2% nitrogen, the temperature on the surface of Mars only fluctuates between 00 C and -300 C.

In relation to other planets, Mars is very well explored, which is also due to the fact that it can be observed very well from Earth. So you can see your icy polar caps very well even with a small telescope. The space probes that approached Mars in the 1970s found that Mars was exposed to very strong bombardment from meteorites. On the south side there is the large crater level, the oldest surface formation on the planet, as well as the Hellas Planitia basin, which has a diameter of 1500 kilometers and a depth of 6 kilometers and was created by a large impact. There are hardly any craters in the northern hemisphere, which is why this area is also known as Vastitas Borealis, which means “great wasteland”.

There are two major regions in the western hemisphere, Tharsis and the Valle Marineris. Tharsis is the largest volcanic region on the planet. A mountain range with a height of 10 kilometers and a radius of 1000 kilometers was formed there by floods of lava. Above it are the 20 kilometer high peaks of the Tharsis Mountains, which consist of the mountains Arsia Mons, Pavonis Mons and Ascraeus Mons. The largest volcano is Olympus Mons. It is 27 kilometers high and thus 3 times higher than Mount Everest. At its base it is as wide as Germany. It was discovered by the Mariner 9 probe, after which the Valle Marineris is named.

The Valle Marineris is a huge valley that is 3.2 kilometers deep and covers an area the size of the United States. It is the largest canon system in this solar system. The Valle Marineris became famous in 1997 when the Pathfinder probe landed on Mars and examined rocks in the Valle Marineris.

But Mars also offers another special feature, namely dried up rivers. It began with the fact that in 1877 the Italian astronomer Schiaparelli discovered channels whose origin could not be explained and it is assumed that these were created by extraterrestrials. However, after closer examination, it was found that this was an optical illusion. However, other channels were found which then turned out to be river beds. It was therefore assumed that the water had seeped under the surface and froze there over time. However, some researchers suspect that there is still liquid water in the deeper layers of the earth and they now hope to find extraterrestrial life there.


The moon Phobos, which means something like fear, was discovered in 1877 by the astronomer A. Hall. For almost a century there was nothing more to be seen of him than a mere speck of light. This is how the idea of ​​Phobos was hollow inside and was created artificially. More detailed information about him was only obtained from the probes Mariner 9 (1971), Viking 1 (1976) and Viking 2 (1977). So it turned out that Phobos has a very irregular shape, which is best described as a "three-axis ellipsoid", with the longest axis always pointing to Mars. The surface is littered with craters and covered with split and rock fragments up to 100 meters.

Phobos measures 28 × 22 × 18 kilometers and has a volume of 5000 km3. It orbits Mars at a distance of 9400 kilometers and takes 7 hours and 39 minutes. Particularly interesting on Phobos is the Stickney crater, which bears the maiden name of Hall's wife. It is the largest crater on Phobos, and from its base a system of long grooves extends in all directions. The grooves were created at the same time as the crater due to an impact that almost tore the moon apart.


Deimos was discovered at the same time as Phobos and is also roughly the same shape as this one. Deimos translates to terror and is named like Phobos after the companions of the god of war Mars. Deimos measures 16 × 12 × 10 kilometers and orbits Mars in a time of 30 hours and 18 minutes at a distance of 23,500 kilometers.

Like Phobos, it is also littered with craters, but this was unknown for a long time. Only the Viking 2 probe, which passed Deimos at a distance of 28 kilometers, brought new insights. So found out that most of the craters are hidden under debris. For a long time it was also unclear where the two Martian moons came from. Since the moons have a density of 2 g / cm3 which coincides with the outer asteroid of the asteroid belt between Jupiter and Mars, it is now assumed that the two moons are asteroids that were caught by the gravitational field of Mars and now move around it as satellites.

Jupiter - the largest planet

Jupiter, named after the Roman father of gods, is the heaviest planet in the solar system. It is 143,000 kilometers in diameter and 318 times the mass of Earth, more than all other planets in the solar system combined. If the mass of Jupiter were even greater, it would probably have become a star. It orbits the sun approximately every 12 years at a distance of 778 million kilometers. Although it has such a large mass, it has a density of only 1.33 g / cm3, significantly less than other Earth-like planets. This is because Jupiter, like Saturn, Uranus, and Neptune, belongs to the gas planet family. Its atmosphere consists mainly of the light gases hydrogen and helium. Towards the center of the planet, pressure and temperature rise sharply, which condenses the atmosphere and changes its properties. The pressure 50,000 kilometers below the uppermost edge of the atmosphere is so great that the hydrogen acquires metallic properties. A huge sea of ​​liquid hydrogen spreads across the surface, covering an area 114 times the size of the earth's surface. White clouds float across the pitch-black sky, but they do not consist of water vapor, but of ammonia crystals.

Because of its size, Jupiter can also be observed very well with small telescopes. However, you can only see the brownish clouds far above the surface. They lie around the planet as strips parallel to the equator, which is caused by the rapid movement of Jupiter. It rotates around its own axis every 10 hours, which also leads to a flattening of the planet.

A special formation in the atmosphere of Jupiter is the Great Red Spot. It is a reddish oval, which is three times larger than the earth and rotates like a cyclone with a speed of 500 km / h counterclockwise. It is the highest and coldest cloud formation on Jupiter and has been observed since 1664.In 1610, Galileo Galilei discovered the four largest moons of Jupiter Io, Europa, Ganymede and Callisto. Meanwhile, 12 other small moons have been discovered around Jupiter. That it has so many moons is probably because Jupiter has a very strong magnetic field, through which it could bind asteroids and other small celestial bodies to itself. The two Voyager probes also discovered a narrow ring of dust that surrounds Jupiter and extends 53,000 kilometers into space from the top layer of the atmosphere. Since the dust particles drift onto the planet over time, they have to be renewed from somewhere. It is believed that a planetary moon near Jupiter is responsible for this.

The moon Io

Io has a diameter of 3630 kilometers and an average density of 3.6 g / cm3which is why it is very similar to our moon on earth. Io orbits Jupiter at a distance of 400,000 kilometers on a strongly eccentric orbit that is caused by the gravitational force of the other moons. Due to the great attraction of Jupiter, Io is severely deformed and heated up so that it is liquid inside. It has a very colorful surface caused by large brown to red colored lava lakes and volcanoes, which hurl sulphurous magma at a speed of 3000 km / h 100 kilometers into the air. The entire surface of Io is littered with craters, but these were not caused by impacts. This is a sign that Io is still quite young.


The moon Europa has a diameter of 3,138 kilometers and a density of 3.04 g / cm3. It has almost the same properties as our moon. In contrast to our moon, however, it is completely smooth and covered with a layer of ice 75-100 kilometers thick. This is also the reason why Europe shines much brighter than our moon. The researchers suspect that there could be a layer of liquid water between the ice sheet and the subsurface, which is indicated by dark lines in the ice, which are probably cracks that have filled with water that has subsequently frozen.


At first glance, the moon Ganymede looks very similar to our moon. When viewed up close, however, it can be seen that it consists largely of ice, which is also due to its low density of 1.9 g / cm3 explained. Ganymede has a diameter of 5262 km and is therefore approx. 100 km larger than Saturn's moon Titan.

Dark spots on the surface, so-called Regio, are probably the oldest formations on Ganymede. In the largest region, the Regio Galileo, there are remains of basins made up of concentric and curved ridges. These are 50 km apart, are 10 km wide and 100 m high.

A peculiarity that occurs very often on Ganymede are bright stripes that extend several kilometers in all directions and form a furrowed terrain. In addition, sulci, areas with parallel grooves, are formed by them. The region was named after the discoverers of Jupiter's moons, including Galileo, Marius, Nicholson. The craters are named after ancient civilizations such as Babylon, Sumer, etc.


Callisto is the quietest of Jupiter's four moons. It is a lifeless ice world with no internal activities.

Its surface is marked by countless meteorite impacts and the only craters that still show activity are already very flattened. The surface is made up of ice and rocks, and it can be assumed that the moon is also made of ice inside, possibly in liquid form. These assumptions are supported by the fact that the density of the moon is just 1.8 g / cm3 amounts to. It is icy cold on the surface of Callistos, which has a diameter of 4800 km. The temperatures during the day are -120 0 C and at night -190 0 C. Special features of Callistos are the two impact craters Walhalla and Asgard. Bright rings run from them like waves in all directions.

Incidentally, it was recently discovered that Callisto has a thin atmosphere. It consists of carbon dioxide, has a pressure of only 7.5 trillionths of a bar and a temperature of minus 1200 C. It was discovered by Robert W. Carlson of the Jet Propulsion Laboratory (JPL) while evaluating infrared measurements from the Galileo probe. The carbon dioxide is likely to be constantly being replaced, either from within the planet or through the conversion of surface material by cosmic rays.

Saturn - Ringed Giant

Saturn is the second largest but lightest planet in this solar system. Its density is only 0.69 g / cm3. This is because Saturn is mostly made up of hydrogen. It rotates very quickly around its axis, which means that a day on Saturn only lasts about 11 hours. In addition, the equator is severely deformed by the rotation, which means that the diameter of the planet at the equator is 120,600 kilometers, but only 98,000 kilometers at the poles.

Under the -1300 In the cold upper atmosphere, Saturn is relatively hot, which is due to the fact that Saturn gives off more heat than it absorbs. For example, storms caused by the heat can be found in the atmosphere, moving at speeds of 1,800 km / h. In some cases, one can also observe large hot gas bubbles that rise from the depths and sometimes develop into hurricanes.

A special feature of Saturn are its two rings that surround Saturn at the equator. They consist of pieces of ice and rocks the size of golf or basketball and orbit Saturn at a distance of 272,800 kilometers. They are guided by the many moons of Saturn, which creates a complicated pattern in the ring structure of the rings. However, nothing more is known about the formation of these one kilometer thick rings.

The Saturn moon Titan

Titan is the largest and most famous of Saturn's moons. It has a diameter of 5,150 kilometers, but its density is only 1.9 g / cm3. This is because the Titan consists largely of water, in the form of ice, which gave scientists the hope that life could exist on Titan. The titanium is completely cold and has a temperature of approx. -1800 C. It is probably the only moon with a dense atmosphere. This mainly consists of nitrogen, but also methane and argon. It extends up to a height of 200 kilometers and its pressure is 1.5 times higher than in the earth's atmosphere. The surface cannot be observed from space because Titan is covered by an opaque layer of orange cloud. The surface consists largely of methane, which is to be found there in liquid form in lakes and rain or as a solid due to the low temperatures.

In addition to Titan, Saturn also has the moons Mimas, Enceladus, Thetys, Dione, Rhea, Hyperion, Japetus and Phoebe. However, these are not very interesting scientifically, which is why they are not explained in more detail here.

Uranus - One ocean

Uranus was discovered in 1781 by the astronomer W. Herschel, but it was not until 1986 that the Voyager 2 probe provided further information about it.

Its diameter is four times that of the earth. As on Earth, auroras also arise on Uranus at the poles. Electrically charged particles, held in place by the planet's magnetic field, crash onto the surface, colliding with gas molecules on the way and causing them to glow. However, the auroras on Uranus are ten times brighter than those on Earth.

Another peculiarity of Uranus is that its equatorial plane is tilted so far against the orbital plane that it seems to be turning on its side. Strangely enough, the magnetic poles are not located at the geographic poles either. it is therefore assumed that Uranus must have collided with a body the size of the earth in the early history of the planet. The planet itself was turned on its side, but its inner dynamo, which is responsible for the planet's magnetic field, was not rolled quite that far.

The atmosphere of Uranus consists of 88% hydrogen and 12% helium, with additions of methane. Because these elements absorb the red wavelengths of light, Uranus appears blue-green in color. The planet's atmosphere is 11,000 kilometers high and, although Uranus gives off more heat than it absorbs, the planet's outer gas layers are -1760 C cold. The winds of Uranus are much calmer than those on other planets and have a speed of "only" 560 km / h.

The surface of the planet is a single ocean, which consists of water, ammonia and methane. Although it doesn't seem so, the ocean is scalding hot, warmed by the stony, earth-sized planetary core.

Uranus has eleven rings that are inclined like the equator. They are made of rocks, but possibly also of organic matter.

What is also noticeable about Uranus is that it orbits the sun in an uneven orbit. This suggests a still unknown planet.

Neptune - ice blue planet

The Neptune was discovered in Berlin in 1846. Its orbit was determined by deviations from Uranus. It has a diameter of 49,500 kilometers and its mass is 17 times that of the earth. It orbits the earth at an average distance of 4.5 billion kilometers and takes 165 years to complete one orbit.

Because of its great distance, it is very difficult to observe it with a telescope. This is how most of the information about Neptune was obtained from the Voyager 2 probe. It is therefore known that the planet's atmosphere is made up of hydrogen, helium, water, ammonia and methane. Since the methane absorbs the red wavelength of the light, Neptune shines in an ice-blue light.

Another peculiarity of the planet is the Great Dark Spot, a cyclone that rotates counterclockwise around the planet. To the south is the Little Dark Spot, a cloud of methane gas that rises from lower levels of the atmosphere. Both move at a speed of 1,200 km / h.

The Voyager 2 probe also provided more information about Triton, Neptune's largest moon. It was found that Triton has a thin atmosphere of nitrogen. It also has “ice volcanoes”, which means that ice moves very slowly to the surface, like lava.

Pluto - Distant dwarf

Pluto was discovered by C. Tombaugh on January 21, 1930. It has a diameter of 2,300 km and a mass of just 1/400 that of the earth. It moves in a strongly elliptical orbit, which means that it is sometimes in front of Neptune. When orbiting it, it is up to 7.3 billion kilometers from the sun and takes 248 years to do so. Since it pendulums as it orbits it, experts suspect that there is another planet near Pluto.

Very little is known about the planet itself as it has not yet been further explored by probes. It is known that the planet rotates for 6.39 days and that there are also signs of a thin atmosphere. Because of the great distance from the Sun, it is very dark on Pluto and the temperatures never exceed -1900 C brand. The surface of the planet consists mainly of ice and rock. Above this there is a layer of methane frost which is concentrated on the polar caps.

In 1987 the moon Charon was discovered. It's half the size of Pluto and mostly made of ice. Both together form a double planet system.

Chapter 3: Space

The history of space travel

Just a few centuries ago, people were afraid of a solar eclipse and considered the “earth disk” to be the center of the universe. They considered planets and stars to be gods in flight and appearances like falling stars or weather lights to be messengers of fate. Drought, floods, storm surges and earthquakes were feared as unpredictable signs of God.

After Galileo Galilei announced his first telescope observations of the moon and other celestial bodies at the beginning of the 17th century, imaginative utopian travelogues about journeys to other stars appeared in the 17th and 18th centuries. In Jules Verne's "From Earth to the Moon", some details of space travel are predicted relatively realistically (e.g. weightlessness). The first technically and scientifically justified considerations for venturing into space began in the last decades of the 19th century, especially in the former Soviet Union and Germany. The rocket engine was the focus of interest. It was recognized that one can only leave the earth's gravity if one hurls matter away. Only this recoil principle could then come into consideration for space companies, and efforts in the first decades of the 20th century were initially concentrated on the development of suitable rockets. The advancing development of rocket technology was driven forward by Wernher von Braun during the Second World War, especially in Germany. These findings shifted to the USA and the Soviet Union after World War II.

First steps into space

On October 4, 1957, the USSR launched the first satellite, called Sputnik 1, into orbit. Sputnik itself consisted of an aluminum ball with a diameter of 58 centimeters and weighed 83 kilograms. The sphere contained some devices for measuring temperature and radiation in the earth's atmosphere. He reached an altitude of 228 km to 947 km. Sputnik needed 96 minutes to orbit the earth. In total, Sputnik stayed in space for 57 days.

The world was very surprised at the time, especially the United States, because the Soviet Union was the first to succeed. One spoke of the so-called "Sputnik shock". With this, mankind took the first step into space.

Shortly afterwards Sputnik 2 followed, which with a mass of 508 kg exceeded Sputnik 1 by far. For the first time there was even a living being, the dog Laika, on board, but she died of a lack of oxygen after a few days. After 161 days, Sputnik 2 burned on entering the earth's atmosphere.

On January 31, 1958, the Americans were ready with their first Explorer 1 satellite. Explorer weighed 14 kg, was 15 centimeters in diameter and 203 centimeters long. Explorer 1 reported measurements on cosmic rays and micrometeorites for 112 days. It was through these measurements that the Van Allan radiation belt was discovered. On May 15, the USSR launched the Sputnik 3 satellite. The 1,327 kilogram Soviet satellite carried out measurements of solar radiation, cosmic rays, magnetic fields and other phenomena in space until it was destroyed in April 1960. Explorer 1 was followed by Vanguard 2. Research has shown that the earth is not a perfect sphere, but rather that the poles are flattened. Using solar energy, the satellite transmitted signals for more than six years. In that year NASA (National Aeronautics and Space Administration) was founded. The goal of the Americans was to be the leading nation in space.

Manned spaceflight began with Vostok 1 on April 12, 1961. For the first time a person, Yuri Gagarin, was on board. 1 hour and 48 minutes after take-off, Vostok 1 landed safely in Siberia.

In the following two years five more Vostok flights were completed. Vostok 6 took off on June 16, 1963. Valentina Tereschkowa was on board. She was the first woman in space and orbited the earth a total of 48 times.

In the meantime, the Americans started the Mercury program. On May 5, 1961, Alan Shepard became the first American in space. The spacecraft, named Freedom 7, completed a 15-minute ballistic flight. In a later mission, on February 20, 1962, John Glenn became the first American astronaut to orbit the earth 3 times.

Vozhod was a modified variant of the Vostok spaceship that was designed to bring several cosmonauts into space. On October 12, 1964, the cosmonauts Vladimir Komarow, Boris Jegorow and Konstantin Feoktistow circled the earth 15 times on board the Woschod 1. Thus, the total number of hours spent in space by Soviet cosmonauts increased to 455, while American astronauts stayed in space for a total of only 54 hours. On March 18, 1965, Alexei Leonov managed to get out of the capsule during the Vozhod missions and float freely in space.

The US Gemini program was intended to develop the technology necessary for the flight to the moon. The Gemini spaceships carried two astronauts. They should work for longer periods of time and develop techniques for encountering other spaceships and coupling them into orbits.

During the flight of Gemini 4, Edward White II was the first US astronaut to leave the spacecraft. He spent 21 minutes in space. In December 1965, Gemini 6 and 7 were in orbit at the same time and they met at a distance of only a few meters. Gemini 6 landed after 20 hours in Earth orbit. Gemini 7 continued its flight and remained in orbit for a total of 334 hours. During this almost 14-day flight, medical data was collected about the stay of people in space, which was necessary for securing the planned ten-day Apollo program to the moon. In addition, the flight should prove the reliability of the systems. On the flights of Gemini 10, 11 and 12, the encounter and coupling with a target vehicle were rehearsed.

After the end of the Gemini program in November 1966, the total number of hours spent by American astronauts in space had increased to over 2000, which exceeded the total number of Soviet hours. In addition, the Americans had been outside spacecraft for a total of 12 hours.

On the way to the moon

After exploring near-Earth space, the moon was now the target of many space flights. However, the first attempts by the United States and the former Soviet Union failed. It was not until September 12, 1959 that the USSR reached the moon with Luna 2 after 36 hours of flight time. Since that day, many spacecraft have been sent to the moon by both states. Luna 3 launched on October 4, 1959 and provided the very first images of the back of the moon. In May 1961, then US President John F. Kennedy started the Apollo program. He said that a person will land on the moon before the decade is up and will be brought back safely to earth.

The American satellite Ranger 7 was launched on July 28, 1964. The aim was to transmit images of the lunar surface as the satellite crashed onto the moon. Ranger 7 transmitted over 4,000 images from altitudes of 1,800 kilometers to around 300 meters and gave people the first close-ups of the moon before it crashed onto the moon.

After the hard landings, the former Soviet Union made a soft moon landing with Luna 9 for the first time in January 1966. On May 30th of the same year the USA followed with Surveyor 1, which also landed softly on the moon. He sent many close-ups back to Earth. In preparation for the Apollo program, the Americans made a number of other unmanned flights, including the soft landings of the Surveyor 3 and 5 probes in 1967. Both lunar probes transmitted a large number of television images from the lunar surface after each two days of flight. Surveyor 3 also took samples of the lunar soil. Surveyor 5, on the other hand, chemically analyzed the lunar surface. That was the first analysis of an alien celestial body on site.

Another lunar probe was the American lunar orbiter. In 1966 and 1967, five lunar orbiters orbited the earth's satellite and radioed thousands of photos to earth. With the help of these images, possible landing sites for the Apollo lunar landing program were searched for. 1967 was a bad year for both space nations. During a ground test of the spaceship Apollo in Cape Kennedy (today it is called Cape Canaveral) on January 27, a fire broke out in the command module, which was occupied by three men. Since the air inside the spaceship still consisted of pure oxygen at that time, the occupants burned up in a short time. As a result, the Apollo program was postponed for more than a year. During this time, the design and materials of the spacecraft were subjected to a thorough review. The first flight with the new Soviet spaceship Soyuz was not so successful either. During the re-entry into the earth's atmosphere and the deployment of the landing parachutes, the suspension lines became tangled. The capsule crashed. The Soviet space program was postponed for almost two years.

In October 1968 the Americans made the first attempts to prepare a manned flight to the moon with the Apollo program. With the new Apollo spacecraft with a Saturn 1B engine, the astronauts Schirra, Cunningham and Eisele orbited the earth 163 times. They checked the performance of the spaceship, photographed the earth and broadcast television images.

In December they made their way to the moon. Apollo 8 orbited the moon ten times and then returned safely to Earth with the astronauts Borman, Lovell and Anders on board. (Further information: Apollo 8 - The first manned flight to the moon, page 23)

During the flight of Apollo 9, the decoupling and coupling of the Apollo lunar vehicle was tested during a 151 orbit. The flight of Apollo 10 should complete preparations for landing on the moon. As planned, Stafford and Cernan transferred from the Apollo command module to the lunar module, uncoupled and approached the lunar surface up to an altitude of 10 miles. Then they flew back again and docked again. The two astronauts got into the command capsule and pushed the lunar module off. Finally, they fired the rocket to overcome the gravitational pull of the moon and fly back to earth. Now the Americans with Apollo were ready to send a person to the moon.

Apollo 11 was launched on July 16. After being in lunar orbit, Edwin Aldrin and Neil Armstrong transferred to the lunar capsule as previously planned. The third astronaut, Michael Collins, stayed in orbit and piloted the command module. On July 20, the lunar module flew down to the surface of the moon and landed on the edge of the Mare Tranquillitatis. Neil Armstrong commented on the landing with the words: "The eagle has landed". A little later he went down the ladder in his misshapen spacesuit and stepped onto the surface of the moon on July 21 at 3:56 a.m. Central European time. His first words were: “It's a small step for a person, but a big step for mankind.” Then Aldrin got off the lunar module. The two astronauts walked (or rather hopped, due to the gravitational pull of 1/6) for more than two hours on the moon. They collected 21 kilograms of soil samples, took photos and carried out a wind experiment. Millions of people watched live television broadcasts from the moon via satellite.

To start again from the moon, they used the lower part of the lunar module as a launch pad that remained on the moon. The upper part flew back to the command and service capsule for docking. The return flight went without any particular incident. The spaceship landed on July 24th in the Pacific Ocean near Hawaii and was recovered from provided ships. The astronauts were quarantined for 3 weeks to avoid possible poisoning of the earth by living lunar organisms.

The Soviet Union did not send people to the moon, it did send some unmanned spaceships. In January 1969, Soyuz 4 and 5 met in orbit and docked with each other. Two cosmonauts switched from Soyuz 5 to Soyuz 4. In October 1969 Soyuz 6, 7 and 8 took off one day apart, met in orbit, but did not dock. On November 14, 1969, the Americans began their next moon landing. Apollo 12, with the astronauts Charles Conrad jun., Richard Gordon jun. and Alan Bean on board, similar to Apollo 11. The landing site was near the Riphäus Mountains, not far from where the spacecraft Surveyor 3 had landed two years earlier. Once there, Conrad and Bean dismantled some parts of the Surveyor for later investigation on Earth. A real sensation then arose in the NASA laboratory on earth, because bacteria were discovered in the camera that survived there for 31 months despite the enormous temperature differences and the strong UV radiation. Otherwise, the astronauts collected more soil samples and carried out scientific experiments. On November 24th, the spaceship landed back on earth. The quarantine measures were repeated.

Apollo 12 had some technical innovations compared to Apollo 11, especially control and landing accuracy were improved. These changes turned out to be successful with Apollo 12 that intended to land Apollo 13 on rugged lunar terrain. On April 11, 1970, Apollo 13 launched with astronauts Lovell, Haise and Swigert. An oxygen tank exploded during the flight. The astronauts found themselves in an extremely critical situation and decided to abandon the planned landing on the lunar surface. It was decided to fly around the moon and then return to earth. Fortunately, everything went well and on April 17th they flooded safely in the South Pacific. (Further information: Apollo 13 - The Unfortunate Flight, page 26)

The former Soviet Union now launched Soyuz 9, manned by two cosmonauts. With this she set a long-term flight record of almost 18 days in June 1970. In addition, Luna 16 landed on the moon in September 1970, collected rocks and sent it back to Earth. With Luna 17 in November 1970, the USSR brought the Lunochod 1, a self-driving lunar vehicle, to the moon. Lunochod 1 was equipped with a television camera and solar batteries for energy supply. The lunar vehicle was steered from the earth for 10 days and covered 10 km.

In the meantime, the Americans had made considerable technical changes to Apollo to prevent another accident like that of Apollo 13. Now they were ready again to tackle the next moon landing. The crew of the spaceship Apollo 14 (launch: January 31, 1971) took over the mission of Apollo 13. One astronaut was Shepard, who had already made a successful flight in 1961 with the Mercury capsule. He and Edgar Mitchell successfully landed in the lunar module in the rugged Fra Mauro region. Astronaut Stuart Roosa stayed in the command capsule on the lunar orbit. Shepard and Mitchell spent more than nine hours exploring what is believed to be some of the oldest rocks ever discovered. They collected about 43 kilograms of geological samples and set up scientific instruments. The astronauts returned to Earth on February 9, 1971 without incident.

Apollo 15 launched on July 26, 1971: Scott was the flight commander, James Irwin the pilot of the lunar module and Alfred Worden the pilot of the command module. Scott and Irwin landed their ferry on the edge of the Mare Imbrium near the 366 meter deep Hadley Rille, part of the Apennines mountain range, which is one of the highest mountain ranges on the moon. They spent 2 days and 18 hours on the lunar surface. The astronauts also drove an electrically powered four-wheel drive moon car more than 28 kilometers around Mount Hadley. They also installed scientific instruments and collected 91 kilograms of rock samples. Among the samples was a 4.6 billion year old piece. A television camera that was left on the moon was used to record Scott and Irwin's departure from the lunar surface. Apollo 15 also deployed a 36-kilogram satellite to measure gravity and magnetic fields in the lunar orbit. On the return flight, Worden took a 16 minute walk in space. At the time, the spaceship was over 300,000 km from Earth, a record distance for an exit from the spaceship. Without any special incident, the Apollo 15 astronauts landed about 530 kilometers north of Hawaii on August 17th. It was the first moon landing crew that did not have to undergo quarantine.

On April 16, 1972, the astronauts Young, Duke and Mattingly took Apollo 16 to the moon to explore the Descartes Highlands. While Mattingly remained in orbit, the other two astronauts landed on April 20. They spent more than 20 hours on the moon and carried out a series of experiments, whereby the nuclear energy of a small supply unit provided the necessary electricity. The astronauts drove 27 km in the moon car and collected more than 97 kilograms of rock samples.

The missions to the moon planned by the United States were completed with the flight of Apollo 17 from December 6-19, 1972. During their smooth 13-day journey, the experienced astronaut Cernan and Harrison H. Schmitt spent 22 hours on the moon, drove 35 kilometers in the moon car and explored the Taurus-Littrow Valley. (Further information: Overview of the Apollo Missions, page 28)

Bases in space

The Salyut 1 space station was launched on April 19, 1971. It was 20 meters long and about 4 meters in diameter. 3 days later, Soyuz 10 was attached on a trial basis. However, the crew did not switch. The space station was not occupied by Soyuz 11 until June. The three cosmonauts set a long-term flight record of 24 days while conducting numerous experiments. However, there was a tragic accident on the way back to earth. The cosmonauts fell victim to a leak in the breathing air supply system. Since they were not wearing spacesuits, death overtook them quickly. As a result of this accident, the Soviet program suffered another setback.

Meanwhile, the US was planning the Skylab space station. However, this was almost 5 times as heavy and also had a volume about 3.5 times as large as the Soviet Salyut station. Skylab was intended as a laboratory in orbit with which one wanted to study the sun, the earth and weightlessness further. When it took off on May 25, 1973, Skylab was somewhat damaged, but the crew repaired the space station during a 28-day flight. A total of 3 crews, each with 3 astronauts, were involved in the Skylab project, which took around 46,000 images of the earth and 175,000 images of the sun. During the 34,981. Orbit on July 11, 1979, Skylab crashed to earth and sank in the Indian Ocean.

In April 1973, the Salyut 2 space station was launched, but it apparently got out of control and lost various parts in orbit. This was followed by a number of other Salyut space stations. Among other things, Sigmund Jähn was there in 1978 as the first German (GDR) in space. In 1984 one of the most remarkable flights of the Salyut / Soyuz series took place. The cosmonauts Leonid Kisim, Wladimir Solowjow and Oleg Atkow spent a total of 237 days on board Salyut 7. They set a new record. The now abandoned Salyut 7 space station is still in orbit.

In 1975 the Apollo-Soyuz-Tesflug took place, the first international company in manned space travel. Two Soviet cosmonauts and three American astronauts tested the coupling of the two spaceships.

In the early 1980s, the US focused primarily on the Space Transportation System (STS), better known as the Space Shuttle. The shuttle, a multi-purpose space glider, can transport payloads of up to 30,000 kilograms and 7 crew members. The space transporter was designed for about 100 flights. With the help of its wings, the space transporter is able to land like an airplane when it returns to Earth.

The first space shuttle mission was launched on April 12, 1981. John Young and Robert Crippen flew aboard the Columbia spacecraft. During this test flight, however, the space transporter was still unloaded. It was not until the fifth space shuttle flight that the Columbia astronauts stationed two commercial communications satellites. In addition, a defective satellite was repaired on the eleventh mission of the space shuttle in April 1984. And during the twelfth mission in November 1984, two broken satellites were recovered and returned to Earth.

After two successful test flights, the German space laboratory Spacelab was successfully launched into space. The German scientist Ulf Merbold was involved in the first test in 1984. A second flight, known as the D1 mission, took place in November 1985. The room laboratory was a real research facility with many scientific and technical facilities, with the help of which a wealth of experiments could be carried out. In addition, medical experience was gained during the D1 mission, which was intended, among other things, to help clarify and remedy space sickness that occurs during space flights.

January 28, 1986 saw the greatest catastrophe in space travel. The space shuttle Challenger exploded about a minute after take-off because an engine bored into the fuel tank filled with hydrogen and oxygen. All seven astronauts were killed in the accident. In addition to the astronauts, Christa McAuliffe, who had been selected as the first teacher in space the year before, was also on board. Due to the accident, the shuttle flight program was stopped immediately and major investigations into the disaster were initiated.

On February 19, 1986, the USSR launched the Mir space station as the successor to the Salyut space station. The Mir should always be manned by 2 cosmonauts. On April 12, 1987, the 18,000 kilogram astrophysical module Kwant docked at the Mir station in order to observe a supernova in the Large Magellanic Cloud with 4 X-ray telescopes. These examinations could not be carried out from the earth because the atmosphere absorbs the X-rays. With a stay of 366 days in space, the cosmonauts Vladimir Titow and Musa Manarov set a new long-term record in 1987/88.

After long renovations, the shuttle launch program was resumed on September 29, 1988 with the flight of the Discovery and its crew of five astronauts. During this mission, the crew put a NASA communications satellite into orbit. The success of this 26th flight encouraged the United States to resume an active launcher program.

On November 15, 1988 Buran, a reusable spaceship resembling the American space shuttle, completed its maiden flight around the earth, only three hours long. To this day it was to remain the only flight that was ever carried out with the Russian shuttle. Buran was launched into space with Energija, one of the most powerful rockets ever built.

On April 24, 1990, the long-held, US $ 1.5 billion Hubble space telescope, named after Edwin Hubble, one of the greatest astronomers and explorers of the 20th century, was stationed with the space shuttle.The telescope has a telescope mirror 2.4 meters in diameter, 13.3 meters long and weighs more than 11,000 kilograms. It orbits the earth at an altitude of around 600 kilometers. The ESA (European Space Agency) provided the solar cells for the energy supply. Europeans have 15% of the observation time available for this.

In the future it will be serviced by astronauts in orbit and can even be brought back to earth with a shuttle in the event of a serious defect. For the first time there is the opportunity to use a telescope to the limit of the theoretical possibilities, since there are no disturbing weather phenomena. With the telescope it will be possible to see further into space than before, and thus into the earliest past of the universe. The work of the telescope is coordinated in a purpose-built institute in Baltimore. Since then, it has provided excellent images.

In the spring of 1993, the two German astronauts Hans Schlegel and Ulrich Walter were transported into space on the Columbia shuttle during the D2 mission. About 90 experiments were carried out there.

After the end of the Soviet Union, Russia continued its space missions. Some of these missions were carried out in cooperation between Russian and German space organizations. Among others, Ulf Merbold was on board the Russian space station Mir in 1994 and Thomas Reiter the following year. Some material science experiments were carried out. The main focus was on examining the effects of weightlessness on the human body in order to gain knowledge about building our own space station.

Exploring the solar system

Shortly after the launch of the first Sputnik 1 satellite, both the Americans and the USSR tried to send a probe to Venus and Mars, respectively. However, due to the great distance and the long journey involved, the first attempts failed. For the first time, a planet passage with functioning measuring devices was successful in 1962, when the Mariner 2 probe flew past Venus at a distance of 35,000 kilometers. Venera (Venus) 2 and 3 first brought landing capsules into the Venusian atmosphere in 1965, but no data could be obtained from them. With Venera 4, the USSR determined the first measured values ​​in 1967 while flying through the atmosphere. A functional device landed for the first time in August 1970 with Venera 7. It worked long enough to provide 23 minutes of temperature readings from the dense atmosphere. A year later, the first flight to Mars was also successful. The former Soviet Union sent two probes, Mars 2 and Mars 3. Although they crash-landed on Mars, they were still able to transmit data for a short time. At the same time, the Americans launched the Mars probe Mariner 9. A few months later, it orbited Mars for almost a year. She photographed the planet and it was possible to make an almost complete map of the planet.

The USSR sent 4 more Mars probes in August 1973. Mars 4, 5, 6 and 7, however, were marked by various technical glitches.

The US space probes Pioneer 10 and 11, launched in 1972 and 1973, safely crossed the unexplored asteroid belt behind Mars and passed Jupiter in December 1973 and December 1974, respectively. The two 270 kg probes passed the planet at a distance of 130,400 km and 46,700 km, respectively. Pioneer 10 continued its flight out of the solar system. It was the first spaceship ever sent into interstellar space. (Further information: Pioneer - Ambassadors in Space, page 30)

With the space probe Mariner 10, the USA planned a journey through the inner solar system to the planet Mercury, the closest to the sun. In February 1974, Mariner 10 flew past Venus and used its gravitational pull to enter a specific solar orbit. In March, the probe came close to Mercury up to 692 kilometers and delivered the first images of the planet's surface, which is strongly reminiscent of the moon due to the many craters. During the second encounter with Mercury in September, a completely unexpected magnetic field was discovered. At its third and last encounter in March 1975, Mariner 10 came within 197 miles of the planet.

In August and September 1975, respectively, the American probes Viking 1 and 2 began an eleven-month journey to Mars. The landing units of the Viking probes provided colored images of the landing sites, transmitted meteorological data, registered Marsquakes, analyzed the Martian soil and recorded direct searches for microorganisms. Furthermore, both were equipped with a 3 meter long gripper arm, which could be controlled from the earth for several years. On July 20, 1982 radio contact with Viking 1 was lost and could not be re-established, so that NASA officially declared the Mars lander dead.

The USSR, meanwhile, continued to deal with Venus. Venera 9 and 10 brought landing devices to the surface in October 1975, both of which operated for an hour. The first photos were transferred from the surface of Venus. In 1978, Venera decoupled 11 and 12 probes that landed on Venus in December. Both probes registered an enormous pressure of around 89 bar (earth ª 1 bar). In addition, there is a surface temperature of over 4000 C. With Pioneer Venus 1 and 2, the US also investigated Venus. The latter mapped the entire planet and deployed 5 smaller probes. These analyzed the composition and movement of the atmosphere and their interaction with the solar wind.

Following the success of the Pioneer probes, two more were launched in 1977. Voyager 1 and 2 reached the Jupiter system in March and July 1979, respectively, made a large number of measurements, and took numerous photos. The space probes then flew on to the Saturn system in November 1980 and August 1981, respectively. After staying at Saturn, Voyager 2 was directed towards Uranus, which it reached in January 1986. The probe passed the cloud-covered planet at a distance of 80,000 km, and ten new moons were discovered. The probe even came closer to one moon, Miranda, and transmitted sensational images of this icy celestial body. Then Voyager 2 continued toward Neptune. In August 1989 Voyager 2 also passed this planet and another six Neptune moons were discovered before the probe finally left the range of the planetary orbits. (Further information: Voyager Outer Planets Tour, page 32)

In 1988 the USSR dispatched two probes, Phobos 1 and 2, to land on the Martian moon. The first was lost through human error, and radio contact with the second was lost.

The space probe Magellan was launched on May 4, 1989 with the American space shuttle Atlantis. In August 1990, she entered Venus orbit and, after initial difficulties, began scientific work in mid-September. Magellan scouted the surface of the neighboring planet and then mapped it.

In October 1989 NASA, in cooperation with ESA, launched the Jupiter probe Galileo, which reached Jupiter in December 1995 after a tortuous path through the inner solar system. Since then, it has been in its orbit, exploring Jupiter and its moons. (Further information: Galileo in Jupiter's orbit, page 34)

It was not until 1996 that the USSR sent another probe to Mars. Unfortunately, it already burned up after a failed start in the earth's atmosphere.

The Americans were more successful with their project. They sent out Pathfinder, who abandoned Sojourner on the surface in 1997. This little robot had a camera on board with which it took many photos and sent them to earth. However, the light needs about 10 minutes for the distance. That is why it was equipped with complex electronics that enabled it to see obstacles and, if necessary, to avoid them independently. He analyzed the composition of the rocks and the atmosphere. (Further information: Pathfinder Exploration, page 35)

In 1998 the American Global Surveyor went into orbit around Mars and mapped the surface of Mars.

The future of space exploration

In October 1997, the Cassini-Huygens double probe was sent on its way as a joint project between ESA and NASA. In the summer of 2004 she will then take a close look at the Saturn moon Titan. Once there, she should look for the Huygens immersion capsule to decouple from the Cassini probe and plunge into the sea of ​​clouds of Titan. She should search for organic substances and also send the first recordings of the strange world to earth. Together with Russia, Canada, Japan, the USA and the 13-member European Space Agency, a permanent space station is being planned to be assembled in space. The international space station (International Space Station = ISS) with the name Alpha is planned to be completed around 2002. (Further information: Alpha - The International Space Station, page 35)

With around a dozen new technologies on board, the Deep Space 1 probe was launched at the end of 1998. The ion drive with 85 kilograms of the noble gas xenon, which was used for the first time, is considered particularly spectacular. The probe is scheduled to travel to the asteroid 1992 KD, 193 million kilometers away. In addition, there is a complex electronics, which should ensure that the spaceship finds the safest and best course by itself. It is based on the position of stars and asteroids.

The cost of the American project is just under 250 million marks. The Deep Space 1 mission is the first as part of NASA's “New Millennium” program, in which novel technologies, which are faster and, above all, cheaper, are to be tested for further conquest of space in the next century. If everything goes according to plan, Deep Space 1 should reach the asteroid at the end of July 1999 and pass it at a distance of five to ten kilometers. The “Mars Climate Orbiter” was launched in December last year. After a 670 million kilometer journey, it should reach the orbit of the Red Planet in September 1999 and study the climate there. Another probe to Mars followed in January 1999 - the “Mars Polar Lander”. This is supposed to land near the south pole of Mars in December 1999. The Polar Lander is equipped with two cameras and a robotic arm with which it can grab Martian rocks and churn the surface. Shortly before landing, the Polar Lander is also supposed to drop two mini probes, one of which is to drill about a meter into the surface of the planet in order to examine deeper rock layers. Polar Lander also has a microphone, which is supposed to make it possible for the first time to transmit sounds from another planet to Earth.

In February 1999, the American probe Stardust was sent on a journey of more than four billion kilometers. The probe is to collect samples from the dust tail of comet Wild 2, with which it is to collide in January 2004 between the planets Mars and Jupiter. When returning to Earth, Stardust is scheduled to parachute its cargo over the Utah desert in January 2006.

The US plans to fly a mini-plane over Mars in 2003. According to NASA's ideas, the Mars aircraft should not weigh more than 200 kilograms and only expand its wings in the Martian atmosphere. In addition to extreme winds, the pressure in the atmosphere is only one hundredth of the pressure of the earth's atmosphere, which places great demands on the aircraft. NASA chose 2003 because it coincides with the centenary of the first flight of a motorized machine.

The European Mars Express probe is scheduled to start in June 2003. A lander weighing 60 kilograms is to be deposited on the neighboring planet on earth. In addition to exploring the surface, fossils as traces of earlier living beings will also be searched for.

There is also a camera on board that will be used to take three-dimensional images of the entire surface of Mars. However, one of the main tasks of the spacecraft is to look for traces of water on the red planet. The years 2003 to 2008 are planned as the research period.

In addition, another probe to Jupiter's moon Europa is planned for 2003 - the Europa-Orbiter. Some more sophisticated plans are of course already in place, for example the Europa Ocean Explorer project, in which a probe is supposed to melt its way through the ice cover in order to then examine the water below. The Europa Ocean Observer is also planned. However, no more precise dates are yet available for both ocean missions.

On December 1, 2004, NASA is planning a probe to the planet Pluto. After Pluto-Express has used the gravitational pull of Jupiter to increase its speed, the probe should reach the planet Pluto and its moon Charon at a distance of 15,000 kilometers at the end of 2012. Once there, he is supposed to photograph the surface of Pluto and Charon and determine the composition of the atmosphere. The data should be sent to earth with a 1.5 meter antenna. After the flyby, he will also examine the outer asteroid belt.

The 60x60x80 centimeter small dwarf satellite LunarSat is to be launched by the European Community with the Ariane V rocket. The satellite would approach the moon up to around 100 kilometers in its orbit and then look deep into the craters at the south pole of the moon with a radar device. A camera could also photograph the polar region. Objects the size of a car would even be recognizable in the pictures. The exact date is still unclear, however.

Even today there are still many unsolved puzzles, but people's urge to research has contributed to the clarification of many unanswered questions, especially in space travel. The Hubble telescope provides us with detailed images of the universe and its planets, space probes reveal to us insights into the formation and structure of our earth and our solar system. This makes the fears of our ancestors seem unfounded and ridiculous.

Apollo 8 - The first manned flight to the moon

The original planning in the Apollo program was a little different. According to Wernher von Braun's studies in the 1950s, the NACA and (from 1958) NASA initially planned to build a space station in orbit from which one could then fly to the moon. This plan was soon overtaken by reality, namely with the launch of the first Sputnik satellite on October 4, 1957.

In the end, it was President John F. Kennedy's speech to Congress on May 25, 1961, in which he announced that a person would be sent to the moon and safely returned to Earth by the end of the decade, that revised the plans made necessary.

The fire disaster in the AS-204, which was later renamed Apollo 1 in honor of the deceased astronauts, then again led to planning changes. The manned missions were only resumed with Apollo 7, during which the team carried out numerous tests and system checks in earth orbit and photographed large parts of the earth's surface from the spaceship for the first time. It was then planned to carry out further test flights in earth orbit. the Lunar Module, the lunar module, should also be tested extensively.

On November 11, 1968, NASA boss Thomas Paine announced that the Apollo 8 mission would orbit the moon for the first time on December 21. The crew included Frank Borman as the commander, James Lovell as the pilot and William Anders as the pilot of the lunar module.

The day of the launch (December 21, 1968) began very early for the three astronauts with the wake-up at 2:30 local time. Borman, Lovell, and Anders first had to undergo final medical examinations. Then they put on their spacesuits and drove the white team bus to launch pad 39A, where the 111-meter-high Saturn V waited in the glaring headlights for its start, which was scheduled for 7:51 am local time. The time of the start was getting closer. Thousands of visitors gathered along the John F. Kennedy Spaceflight Center to experience everything live, and final checks were carried out in the Apollo spacecraft. Apollo 8 lifted off the launch pad exactly at 7:51 a.m.

Apollo 8 entered Earth orbit as planned after the scheduled dropping of the 1st and 2nd stages. At this point the 3rd stage was switched off, but not discarded because it would be needed later. It was the only part of the Saturn rocket that could be switched on again, after all, the lunar module was once supposed to be housed here and pulled out by the Apollo spacecraft halfway between the earth and the moon. The flight plan now provided for two orbits of the earth controlled by autopilot.

After the second orbit of the earth was completed, the engine was ignited and the lunar transition orbit entered. Up to this point, the astronauts could have aborted the mission and returned to Earth in the event of any difficulties. This was followed by the separation from the 3rd stage, which was no longer needed for this mission, as one flew without the lunar module. One tried, however, the decoupling of the lunar module for later missions. To swivel into the lunar orbit, the main engine had to be ignited again for a few seconds, which was intended to reduce speed and achieve an elliptical orbit at the same time.The supposed biggest problem was that this maneuver took place over the back of the moon without direct radio contact to earth, because a few minutes before the main engine was ignited, the LOS, the "Loss of Signal", occurred when Apollo 8 was in the radio shadow of the moon entered. Only at the "Acquisition of Signal" (AOS), the exit from the radio shadow, was a connection established again and you could find out in the control center that everything had gone according to plan. The astronauts now began to photograph and film the moon. Among other things, they flew over the prospective landing site of Apollo 11.

Apollo 8 braked one more time to get even closer to the surface and allow even more detailed images. The television broadcast began at 9:31 pm on December 24th and initially showed the varied, crater-strewn surface of the moon with impressive descriptions by the lunar travelers. With Christmas greetings, the broadcast finally ended at 10:00 p.m. It should remain in the memory of many people who experienced it back then to this day.

During the 10th and last orbit around the moon, the main engine of Apollo 8 was ignited behind the moon to enter the earth transition orbit. Apollo 8 was now on its way back. On December 27th, Apollo 8 was ready to re-enter the earth's atmosphere. The distance to earth was now about 3000 kilometers. The speed had risen to almost 32,000 km / h. The spaceship was turned so that it flew ahead with the heat shield. Now it was a question of whether you had reached the correct entry angle, if not, you either fell uncontrollably towards Earth, or bounced off the uppermost layers of the atmosphere and was thrown into space.

During the entry into the atmosphere, the astronaut was subjected to a pressure of 6.8g and the temperature of the heat shield was at 2,8000 C increased. At this point, as expected, the radio connection was lost because the spaceship ionized the surrounding air envelope, i.e. was surrounded by a kind of plasma envelope that no longer allowed radio signals to pass through. Then the three parachutes opened and Apollo 8 sank to the ground until it finally submerged. This officially ended the Apollo 8 mission.

In addition to the prestige effect, the intensive photographic and film mapping of the lunar surface should be mentioned here. All medical results taken together, the doctors at NASA agreed that even a long stay in weightlessness or under the low gravity of the moon, as was to be expected with a manned moon landing, does not pose a serious health risk to the astronauts was to be expected.

Apollo 13 - the unfortunate flight

Millions of people around the world watched in front of the television screen as the first humans set foot on the moon on July 21, 1969: the two Apollo 11 astronauts Neil Armstrong and Edwin Aldrin. When Apollo 12 touched down four months later, the enthusiasm and interest of the public had clearly subsided. The flights to the moon and the successful return had quickly become habit and routine. While around half a million people made the pilgrimage to Cape Kennedy at the start of Apollo 11, in April 1970 there were just 100,000. However, that was to change suddenly three days later.

A completely different region on the lunar surface had been chosen for Apollo 13: the somewhat more mountainous area of ​​the Fra Mauro crater, in which rocks with a significantly older age were expected.

Fred Haise, Thomas Mattingly and James Lovell, who had already gained space experience with Gemini 7 and 12 as well as Apollo 8, were planned as crew. A few days before the start, the doctors found rubella on substitute Charles Duke and then examined all of the astronauts. Mattingly was immediately banned from flying. A few hours before the start, NASA decided not to abort the mission and substitute John Swigert became the pilot of the Apollo 13.

The Saturn V, weighing a total of 3300 tons and 111 m high, took off from Cape Kennedy on April 11, 1970 at 8:13 p.m. CET. But a few moments later the first minor breakdown occurred: After the first stage of the rocket could be dropped without any problems, one of the five engines of the second stage switched off too early. Nevertheless, Apollo 13 reached the intended orbit altitude in 190 kilometers without any further difficulties. It circled the earth one and a half times and swiveled into the transition orbit to the moon at 10:48 p.m. CET.

The next two days were routine with television broadcasts and some flight maneuvers, with the spacecraft Odyssey being swiveled around and the lunar module Aquarius pulled out of the third stage. Then April 14, 1970: The astronauts inspected the Aquarius lunar module in front of the cameras and informed the ground station in Houston that everything was in order. Shortly after the television broadcast stopped, the astronauts suddenly heard a loud bang and felt a slight vibration. An alarm was triggered because the loss of energy on board the Odyssey had become critical. At 4:07 a.m. CET, Commander John Swigert picked up the microphone and spoke the words that, like Armstrong's sentence, wrote space travel history after stepping on the lunar surface: “Hey Houston, we've got a problem here!” (= “Houston, we have a problem . ")

In the next few hours there was hectic activity on earth. Technicians and engineers were brought out of their beds, radio and television stations immediately interrupted their programs and the control room in Houston, which was almost empty at the time, filled up within a very short time. In the meantime there were further malfunctions on board, one of the fuel cells was receiving too little oxygen and threatened to fail. Looking out the window, James Lovell saw a cloud of gas drifting away from the spaceship and Fred Haise registered that one of the two oxygen tanks was dead. For safety reasons, Houston ordered the performance of the intact fuel cells to be shut down, which should avoid further disruptions, but the command capsule would from now on also be without energy.

The astronauts got into the still functioning lunar module Aquarius, locked the connection flap to the control unit and started the self-sufficient energy and oxygen supply. Over the next few days, the moon mobile, designed for only two people, became a lifeboat for the three astronauts, especially since the temperature in the command capsule had dropped rapidly.

At 6:03 a.m. CET, NASA officially announced the cancellation of the Apollo 13 mission in Houston. Meanwhile, the Mission Control Center was trying feverishly to do whatever was necessary to save the lives of the three astronauts.

After Apollo 13 had calmed down for a bit, it was decided that the 15 tonne third stage rocket would be the only scientific experiment to be dropped at a precisely calculated point when it was flying past the moon. It succeeded and the step hit southwest of the Landsberg crater in Oceanus Procellarum. The shock was registered by the Apollo 12 seismometer 87 miles away. It was followed by a moonquake, which only subsided 3 hours and 20 minutes later.

In Houston the decision had been made to fly the spaceship around the moon and then return to Earth. Apollo 13 then disappeared behind the moon exactly as planned and radio contact was broken off for half an hour. Now you were on the right course towards earth.

On April 17, 1970, three days after the accident, the temperature in the ferry and the capsule was almost zero0 C dropped. At 2.15 p.m., the capsule and supply section were separated from each other and the full extent of the disaster was visible for the first time: the protective covering had been torn off on the entire side of the supply section. Lovell and Haise filmed and photographed the supply section in a documentary manner in order to later be able to produce material for clarifying the cause of the explosion.

Then they switched on the still functioning fuel cells of the command capsule again. In fact, the fuel cells were never designed to be switched off and on again. Nevertheless everything worked without any disturbances. The anxious question in those minutes was whether the heat shield had survived the explosion unscathed, if not ...

The critical reentry phase began at 6:53 p.m. CET. At 39,700 km / h you raced towards the earth. As expected, radio contact broke off. Five minutes later, Commander James Lovell reported on the radio again and confirmed that everything was OK. The Apollo capsule fell to earth, the parachutes unfolded and at 7:07 p.m. the damaged command capsule watered down. Now they began to investigate why the accident happened. A final report was presented on June 15, 1970. After that, a long chain of unfortunate circumstances led to the explosion of the oxygen tank. The construction of the heating coil was changed in 1965, but had forgotten to replace the thermostat switch. During the flight the temperature rose from 270 C, at which the thermostat would normally have been activated, temporarily to 5400 C at. The Teflon-coated insulation melted and a short circuit occurred in the cables after 56 hours of flight, which in turn led to partial combustion of the oxygen in the tank. The residual oxygen then exploded, tore off the outer casing of the capsule, damaged tank # 1 and an antenna pointing to the earth.

A number of improvements were made after the accident. Finally, after several postponements, Apollo 14 took off on January 31, 1971. On February 5, it landed at Fra Mauro crater, the landing site intended for Apollo 13.

Apollo missions at a glance

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Pioneer - ambassador in space

On March 2, 1972, one of the largest space projects to date began at Cape Kennedy. The mission goal of Pioneer 10 was to explore Jupiter. The problem was that there was an asteroid belt between Mars and Jupiter that had to be broken. The 270 kg Pioneer 10 probe was brought to the record speed of 14.3 kilometers per second (51,480 km / h) within 17 minutes with an Atlas Centaur rocket. It passed the moon just twelve hours after it was shot down - the astronauts on the Apollo missions needed two to three days for this journey.

The next station on the way to Jupiter was Mars, then 80 million kilometers away, which the probe reached at a huge speed of 120,000 kilometers per hour. From there she had to cross the asteroid belt, believed to be extremely dangerous, a zone of kilometer-sized chunks and small pieces of rock between the inner and outer planets. Contrary to all fears, the probe managed to fly through in early November 1973 without the slightest scratch. In the meantime, the sister probe Pioneer 11 has also been sent on a similar course to replace the Pioneer 10 probe in the event of problems.

In December 1973, the probe then came closer to Jupiter and photographed it and its moons from a distance of only 130,000 kilometers. Even the magnetic field and the particle shower near the giant planet could not harm the sensitive instruments in Pioneer. The main task of the probe was thus already fulfilled and the Pioneer 11 probe for Jupiter was superfluous. Therefore it was then redirected to Saturn, which it reached and examined at the end of August 1979. It also flew through his rings undamaged. This made it possible for the Voyager missions to later explore Uranus without “bumping into” the rings. While flying through the rings, Pioneer 11 was accelerated to 110,000 kilometers per hour (30km / s!). The gravity of Jupiter finally catapulted Pioneer 10 out of the solar system. When it crossed the orbit of the most distant known planet on June 13, 1983, it was the first human-made missile to leave the solar system. Pioneer 10 is currently over 10 billion kilometers from Earth, and the number is increasing by several million every day. Beyond the planets, the sky researchers hope that Pioneer 10 should track down the limit of the heliosphere - the area in which the solar wind is effective. But until now it was still registering the impact of charged solar particles. Presumably, then, this limit is even further out in space. But it will also fly beyond that, because the probe is no longer exposed to any dangers in the extreme vacuum of interstellar space. Course is the red giant Aldebaran 68 light years (1 LJ = 9.46 trillion kilometers) away.

On March 31, 1997, more than 9,000 days after take-off, the radio links were broken because of the weakening nuclear batteries fed by a plutonium-238 source. And since then, the probe has been just a lonely wanderer in space.

Message from the Pioneer probes

The most interesting thing about Pioneer 10, however, is that the probe carries a message from Earth with it. If the probe ever comes near a solar system, this can then be collected by another life form that has the necessary technology. But the message is not easy to understand either, because other forms of life can do little with our science.

On the gold-plated aluminum plate attached to one wall of the probe, there is a schematic drawing of a hydrogen molecule in the upper left corner. It is believed that if an intelligent life form can retrieve the probe, it will also know something about chemistry. The distance between the two atoms is used as a unit of measurement, since extraterrestrials certainly cannot do anything with kilometers or miles.

Below is a description of the location of the sun. The lines symbolize the directions in which pulsars are located, as seen from the sun. The long line to the right is the direction towards the center of the Milky Way. In addition, the distance to the respective objects is given in binary numbers (also called dual numbers).

At the bottom, it is easy to see our solar system. The distance to the sun can be seen under each of the nine planets. (Also given in binary) There you can also see that Pioneer 10 was sent on its journey from the third planet, flew past Mars and was finally thrown out of the solar system between Jupiter and Saturn.

On the right-hand side there is a picture of a naked couple of people so that the recipients can also get an idea of ​​us. Behind it is a schematic drawing of a Pioneer probe.

Voyager Tour to the Outer Planets

After the great success of Pioneer 10 and 11, which crossed the asteroid belt between Mars and Jupiter for the first time, the USA dared another expedition to the outer planets in 1977. A rare event was also used to launch the two probes. At this point in time, the planets Jupiter, Saturn, Uranus and Neptune were reasonably exactly in line when viewed from Earth. This event only occurs approximately every 177 years. As a result, a spaceship that was shot down from Earth could use the gravity of each of the planets one after the other to increase its speed further.

The Voyager probes weighed around 800 kilograms, which is 3 times as heavy as Pioneer. In addition, she was already very independent. Instead of just capturing what was moving in front of its sensors, the probe could aim its instruments at specific targets, making it an ideal camera platform. Furthermore, Voyager had a well-thought-out technology that enabled it not to fail immediately in the event of operational disruptions. This was very important because it took 40 minutes to establish a radio link to the control center, which could have devastating consequences for the probe while the probe waited for instructions. The video cameras were able to capture an image at 640,000 pixels, which is slightly better than the normal television format. Due to the high resolution of the image, the intention was to move the transmission to the 8.4 GHz band in order to transmit the abundance of data in a relatively short transmission time. But in the fear that a space probe beyond Jupiter could go silent, the decision was made to use the tried and tested system, which sent the data on the 2.3 GHz band, albeit a little slower.

Planet tour by Voyager

Voyager 2 was to be shot down as the first probe because its trajectory had been modified in such a way that it could optionally fly past Uranus after Saturn and would only reach the planet Jupiter after the Voyager 1 probe, which was sent second. The probe was finally launched on August 20, 1977, but shortly afterwards it reported malfunctions. The on-board computer went crazy because it thought the extreme acceleration at the start was an emergency situation. In addition to another mechanical problem, a jammed boom that carried most of the scientific equipment, fuel was also scarce because a course correction required almost 15% more fuel than intended. Therefore, the course was corrected during the meeting with Jupiter and not as planned after the meeting. This effective in-flight transformation of the mission was an innovative element that continued to shape the entire Voyager journey. In addition, the probe still suffered from "hearing damage". Originally, the probe could still receive 100 kHz on both sides of 2.3 GHz, but now only up to 96 Hz at the center frequency, which also constantly changed a little.But later you could use a computer to calculate the constantly changing center frequency in advance and keep in touch with Voyager 2.

The Voyager 1 probe, which was scheduled to launch just 12 days after Voyager 2, was now waiting in Cape Canaveral. After a 4-day delay and some adjustments made due to the problems with Voyager 2, Voyager 1 finally launched on September 5, 1977. By mid-December, both probes were already about 130 million kilometers from Earth. From February 1979, when Voyager 1 came near Jupiter, the probe began to unravel its secrets. Razor-sharp photos were obtained, which reproduced the sight of the yellow and dark orange planets with unprecedented clarity. In the summer, the focus was then on the probe Voyager 2, which was just coming close to Jupiter, which investigated the planet and its moons further, while Voyager 1 moved on to Saturn.

In November 1980, 14 months after Pioneer 11, Voyager 1 approached Saturn and studied its rings more closely after Pioneer 11 took the first step in that direction. Voyager passed Saturn at a distance of 120,000 kilometers. You were literally struck by the amount of data. With that Voyager’s task was done and they too were sent into interstellar space. In the late summer of 1981, the somewhat slower Voyager 2 probe finally arrived at Saturn. Like Pioneer 11 before, it crossed the ring of Saturn.