Space exploration

We go to space.

People and robots go there. They use big rockets to fly. Rockets push hard to reach the sky.

First, a small object named Sputnik went around Earth. Later, a man named Yuri Gagarin flew in a ship. He went around the world once.

Many people went to the Moon. Some even landed on its surface.

Now, we send robots to other planets. They take pictures for us. Space is a very big place!

Space exploration is how we study the stars and planets.

We use robotic probes and human spaceflight to do this. Long ago, people used telescopes to look at space. In the mid-twentieth century, big rockets made travel possible.

During the Space Race, the U.S. and Soviet Union competed. The Soviet Union launched Sputnik 1 in 1957. It was the first object to orbit Earth. In 1961, Yuri Gagarin became the first human in space.

Later, the Apollo 11 mission landed the first humans on the Moon. Since then, many robots have visited other worlds. We have sent probes to Venus, Mars, and Jupiter. Some robots even landed on the surface of Venus.

Now, countries work together on the International Space Station. Private companies also build ships to go to space. New plans aim to build bases on the Moon. We are still finding many new things in our big universe.

Space exploration is the study of outer space. We do this using uncrewed robotic probes and human spaceflight.

People have watched the stars for a very long time. This is called astronomy. In the mid-twentieth century, we built big and efficient rockets. These rockets made physical travel into space a real possibility.

We explore space for many different reasons. Scientists want to do new research. Countries also want to show their strength or work together. Exploring helps us ensure that humans survive in the future.

Space travel works by using powerful rockets to move objects.

First, a rocket must reach a very high speed. This is called orbital velocity. Without this speed, an object cannot stay in orbit. The first human-made object to reach space was a German V-2 rocket. It launched vertically on 20 June 1944 at Peenemünde. It reached 176 kilometers high, which is above the Kármán line. This was a sub-orbital flight because it did not stay in orbit.

History shows us many amazing first steps in space.

The Soviet Union launched Sputnik 1 on 4 October 1957. This was the first object to orbit Earth. In 1961, Yuri Gagarin became the first human in space. He flew aboard Vostok 1 and orbited Earth once. The American Apollo 11 mission landed humans on the Moon in 1969. Between 1969 and 1972, six spacecraft landed humans on the Moon. Later, countries began to work together more often. They built the International Space Station between 1998 and 2011.

There are many important facts about our solar system.

The Milky Way galaxy has 100 to 400 billion stars. There are more than 100 billion planets in our galaxy. Our universe may have at least 2 trillion galaxies.

One very distant object is called HD1. It is 33.4 billion light-years away from Earth. We have also found 5,284 confirmed exoplanets. An exoplanet is a planet that orbits a star other than our Sun.

Space exploration connects to things we see in the sky.

We use robots to visit planets like Mars and Venus. Some robots, like the Curiosity rover, drive on the surface of Mars.

We also send probes to study the Sun. The Parker Solar Probe was launched in 2018. It can get very close to the Sun. This helps us learn about solar wind and space weather. These discoveries help us understand our place in the huge universe.

Space exploration is the physical investigation of the universe beyond Earth. This is done through human spaceflight and uncrewed robotic space probes.

While humans have observed the stars for centuries through astronomy, physical travel requires massive energy. The development of large, efficient rockets in the mid-twentieth century made this possible. Nations explore space for many reasons. They seek to advance scientific research and gain national prestige. Space travel can also unite different nations or provide military advantages. Some believe exploration is necessary to ensure the future survival of humanity.

To travel through space, a craft must master the physics of motion. A rocket must reach orbital velocity to stay in space without falling back to Earth.

The first human-made object to reach outer space was a German V-2 rocket. It launched vertically on 20 June 1944 at the Peenemünde Army Research Center. It reached an apogee, or highest point, of 176 kilometers. This was a sub-orbital flight because it did not reach the speed needed to orbit. In 1949, the Bumper-WAC reached a high altitude and is considered the first object to enter space by NASA.

The early era of exploration was defined by the "Space Race." This was a competition between the Soviet Union and the United States to show technological superiority.

The Soviet Union achieved many early milestones. They launched Sputnik 1 on 4 October 1957, the first human-made object to orbit Earth. This satellite used radio transmitters to emit "beeps" heard worldwide. Scientists used these signals to study the electron density of the ionosphere. In 1961, Yuri Gagarin became the first human in space aboard Vostok 1. He completed one orbit in 1 hour and 48 minutes.

Humanity has also reached many other celestial bodies. The Soviet Luna 2 was the first artificial object to reach the Moon in 1959. Later, Luna 9 achieved the first soft landing on the Moon in 1966. The American Apollo 11 mission completed the first crewed Moon landing on 20 July 1969. Between 1969 and 1972, a total of six spacecraft landed humans on the Moon. We have also sent probes to explore the entire Solar System. For example, Voyager 2 flew by Uranus in 1986 and Neptune in 1989. The Voyager 1 probe became the first human-made object to enter interstellar space on 25 August 2012.

Robotic missions allow us to study environments that are too hostile for humans.

Venus has been a major target for robotic landers. The Soviet Venera 7 was the first to successfully land on the surface in 1970. Venus is one of only two planets outside Earth where humans have conducted surface missions with uncrewed robots. Mars is the other planet where we have landed robotic spacecraft. Some of these, like the Viking 1 mission, operated on the surface for over six years. On Mars, rovers like Curiosity drive across the terrain to collect data.

Space stations provide a place for humans to live and work in orbit.

The Soviet Union launched Salyut 1, the first space station, in 1971. Today, the International Space Station (ISS) is the largest and oldest fully functional station. It has been inhabited continuously since the year 2000. China also operates the Tiangong space station, which is now fully crewed. In the 2020s, new programs like the U.S.-led Artemis Program aim to build the Lunar Gateway and the Artemis Base Camp. These projects involve many international partners working together.

The scale of the universe is truly immense.

The Milky Way galaxy contains an estimated 100 to 400 billion stars. There are more than 100 billion planets in our galaxy alone. In the observable universe, there are at least 2 trillion galaxies. As of late 2022, scientists have confirmed 5,284 exoplanets, which are planets orbiting other stars. One of the most distant known objects is HD1, located 33.4 billion light-years away. Studying these distant objects helps us understand the history and structure of everything in existence.