SPACE EXPLORATION:

SPACE EXPLORATION:

Space exploration is the use of astronomy and space technology to explore the 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, predates 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 and 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, including the first living being in orbit in 1957, the first human spaceflight (Yuri Gagarin aboard Vostok 1) in 1961, the first spacewalk (by Aleksei Leonov) in 1965, the first automatic landing on another celestial body in 1966, and the launch of the first space station (Salyut 1) in 1971.

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 V2s launched by Americans and their German advisors. These suborbital experiments only allowed a very short time in space which limited their usefulness.

FIRST ORBITL FLIGHT:

The first successful orbital launch was of the Soviet unmanned Sputnik ("Satellite I") mission on October 4, 1957. The satellite weighed about 83 kg (184 pounds), and is believed to have orbited Earth at a height of about 250 km (150 miles). It had two radio transmitters (20 and 40 MHz), which emitted "beeps" that could be heard by radios around the globe. Analysis of the radio signals was used to gather information about the electron density of the ionosphere, while temperature and pressure data was encoded in the duration of radio beeps. The results indicated that the satellite was not punctured by a meteoroid. Sputnik 1 was launched by an R-7 rocket. It burned up upon re-entry on January 3, 1958.

This success led to an escalation of the American space program, which unsuccessfully attempted to launch Vanguard 1 into orbit two months later. On January 31, 1958, the U.S. successfully orbited Explorer 1 on a Juno rocket. In the meantime, the Soviet dog Laika became the first animal in orbit on November 3, 1957.

 
Yuri Gagarin, the first person to make an orbital flight of Earth

The U.S. first launched a person into space within a month of Vostok 1 with Alan Shepard's suborbital flight in Mercury-Redstone 3. Orbital flight was achieved by the United States when John Glenn's Mercury-Atlas 6 orbited the Earth on February 20, 1962.

Valentina Tereshkova, the first woman in space, orbited the Earth 48 times aboard Vostok 6 on June 16, 1963.

China first launched a person into space 42 years after the launch of Vostok 1, on October 15, 2003, with the flight of Yang Liwei aboard the Shenzhou 5 (Spaceboat 5) spacecraft.

FIRST PLANETARY EXPLORATION:

The first artificial object to reach another celestial body was Luna 2 in 1959.[2] The first automatic landing on another celestial body was performed by Luna 9[3] in 1966. Luna 10 became the first artificial satellite of another celestial body[4].


The first successful interplanetary flyby was the 1962 Mariner 2 flyby of Venus (closest approach 34,773 kilometers). Flybys for the other planets were first achieved in 1965 for Mars by Mariner 4, 1973 for Jupiter by Pioneer 10, 1974 for Mercury by Mariner 10, 1979 for Saturn by Pioneer 11, 1986 for Uranus by Voyager 2, and 1989 for Neptune by Voyager 2.

The first interplanetary surface mission to return at least limited surface data from another planet was the 1970 landing of Venera 7 on Venus which returned data to earth for 23 minutes. In 1971 the Mars 3 mission achieved the first soft landing on Mars returning data for almost 20 seconds. Later much longer duration surface missions were achieved, including over 6 years of Mars surface operation by Viking 1 from 1975 to 1982 and over 2 hours of transmission from the surface of Venus by Venera 13 in 1982 (the longest ever Soviet planetary surface mission).