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Space exploration

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

Fusée V2
Fusée V2

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.

Apollo CSM lunar orbit
Apollo CSM lunar orbit

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.

Vostok spacecraft
Vostok spacecraft

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.

A Man on the Moon, AS11-40-5903 (cropped)
A Man on the Moon, AS11-40-5903 (cropped)

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.

PIA16239 High-Resolution Self-Portrait by Curiosity Rover Arm Camera square
PIA16239 High-Resolution Self-Portrait by Curiosity Rover Arm Camera square

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.

Yury Usachev in Russian crew quarters
Yury Usachev in Russian crew quarters

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.

Hubble ultra deep field high rez edit1
Hubble ultra deep field high rez edit1

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.

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🖼️ Images & Media (18)
File:AS11-40-5964 (21037459754).jpg
AS11-40-5964 (21037459754).jpg
File:PIA16239 High-Resolution Self-Portrait by Curiosity Rover Arm Camera square.jpg
PIA16239 High-Resolution Self-Portrait by...
File:Fusée V2.jpg
Fusée V2.jpg
File:Vostok spacecraft.jpg
Vostok spacecraft.jpg
File:Apollo CSM lunar orbit.jpg
Apollo CSM lunar orbit.jpg
File:MESSENGER EN0108828359M.png
MESSENGER EN0108828359M.png
File:TIROS-1-Earth.png
TIROS-1-Earth.png
File:Apollo 16 LM Orion.jpg
Apollo 16 LM Orion.jpg
File:Spirit rover tracks.jpg
Spirit rover tracks.jpg
File:Dawn-image-070911.jpg
Dawn-image-070911.jpg
File:Io Tupan Patera.jpg
Io Tupan Patera.jpg
File:Comet Hartley 2.jpg
Comet Hartley 2.jpg

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