Space explorations is the use of astronomy and space technology to explore outer space. Physical exploration of space is conducted both by human spaceflights and by robotic spacecraft.

While the observation of objects in space—known as astronomy—pre-dates reliable recorded history, it was the development of large liquid-fueled rocket engines during the early 20th century that allowed physical space exploration to become a reality. Common rationales for exploring space include advancing scientific research, uniting different nations, ensuring the future survival of humanity and developing military/strategic advantages against other countries. Various criticisms of space exploration are sometimes made, generally on cost or safety grounds.

Space exploration has often been used as a proxy competition for geopolitical rivalries such as the Cold War. The early era of space exploration was driven by a "Space Race" between the Soviet Union and the United States; the launch of the first man-made object to orbit the Earth, the USSR's Sputnik 1, on October 4, 1957, and the first Moon landing by the American Apollo 11 craft on July 20, 1969 are often taken as the boundaries for this initial period. The Soviet space program achieved many of the first milestones under Sergey Korolyov and Kerim Kerimov, including the first human spaceflight (Yuri Gagarin aboard Vostok 1) in 1961, the first spacewalk (by Aleksei Leonov) in 1965, and the launch of the first space station (Salyut 1) in 1971. However, the first man-made objects to reach space were Nazi-Germany's V2 rockets, used as early as the Second World War.

After the first 20 years of exploration, focus shifted from one-off flights to renewable hardware, such as the Space Shuttle program, and from competition to cooperation as with the International Space Station.

From the 1990s onwards, private interests began promoting space tourism and now private space exploration of the Moon (see GLXP).

In the 2000s, China initiated a successful manned spaceflight program, while Japan and India also plan future manned space missions. Larger government programs have advocated manned missions to the Moon and possibly Mars sometime after 2010.

History

The first steps into space were taken by German scientists during World War II while testing the V2 rocket which became the first human-made object in space. After the war, the Allies used German scientists and their captured rockets in programs for both military and civilian research. The first scientific exploration from space was the cosmic radiation experiment launched by the U.S. on a V2 rocket on May 10, 1946. The first images of Earth taken from space followed the same year while the first animal experiment saw fruit flies lifted into space in 1947, both also on V2's launched by Americans and their German advisors. These suborbital experiments only allowed a very short time in space which limited their usefulness.