Courtesy : en.wikipedia.org
Green space exploration
Space exploration is the use of astronomy and space technology to explore outer space.While the exploration of space is carried out mainly by astronomers with telescopes, its physical exploration though is conducted both by uncrewed robotic space probes and human spaceflight. Space exploration, like its classical form astronomy, is one of the main sources for space science.
While the observation of objects in space, known as astronomy, predates reliable recorded history, it was the development of large and relatively efficient rockets during the mid-twentieth century that allowed physical space exploration to become a reality. The world’s first large-scale experimental rocket program was Opel-RAK under the leadership of Fritz von Opel and Max Valier during the late 1920s leading to the first crewed rocket cars and rocket planes, which paved the way for the Nazi era V2 program and US and Soviet activities from 1950 onwards. The Opel-RAK program and the spectacular public demonstrations of ground and air vehicles drew large crowds, as well as caused global public excitement as so-called “Rocket Rumble”and had a large long-lasting impact on later spaceflight pioneers like Wernher von Braun. Common rationales for exploring space include advancing scientific research, national prestige, uniting different nations, ensuring the future survival of humanity, and developing military and strategic advantages against other countries.
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 human-made object to orbit Earth, the Soviet Union’s Sputnik 1, on 4 October 1957, and the first Moon landing by the American Apollo 11 mission on 20 July 1969 are often taken as landmarks 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 Alexei Leonov) on 18 March 1965, the first automatic landing on another celestial body in 1966, and the launch of the first space station (Salyut 1) in 1971. 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 (ISS).
With the substantial completion of the ISSfollowing STS-133 in March 2011, plans for space exploration by the U.S. remain in flux. Constellation, a Bush Administration program for a return to the Moon by 2020was judged inadequately funded and unrealistic by an expert review panel reporting in 2009.The Obama Administration proposed a revision of Constellation in 2010 to focus on the development of the capability for crewed missions beyond low Earth orbit (LEO), envisioning extending the operation of the ISS beyond 2020, transferring the development of launch vehicles for human crews from NASA to the private sector, and developing technology to enable missions to beyond LEO, such as Earth–Moon L1, the Moon, Earth–Sun L2, near-Earth asteroids, and Phobos or Mars orbit.
In the 2000s, China initiated a successful crewed spaceflight program while India launched Chandraayan 1, while the European Union and Japan have also planned future crewed space missions. China, Russia, and Japan have advocated crewed missions to the Moon during the 21st century, while the European Union has advocated crewed missions to both the Moon and Mars during the 20th and 21st century.
History of exploration
See also: Timeline of space exploration, History of astronomy, Timeline of first orbital launches by country, and Outer space § Discovery
V-2 Rocket in the Peenemünde Museum
First telescopes
The first telescope is said to have been invented in 1608 in the Netherlands by an eyeglass maker named Hans Lippershey. The Orbiting Astronomical Observatory 2 was the first space telescope launched on 7 December 1968.As of 2 February 2019, there was 3,891 confirmed exoplanets discovered. The Milky Way is estimated to contain 100–400 billion starsand more than 100 billion planets. There are at least 2 trillion galaxies in the observable universe. HD1 is the most distant known object from Earth, reported as 33.4 billion light-years away.
First outer space flights
Sputnik 1, the first artificial satellite orbited Earth at 939 to 215 km (583 to 134 mi) in 1957, and was soon followed by Sputnik 2. See First satellite by country (Replica Pictured)
Model of Vostok spacecraft
Apollo CSM in lunar orbit
MW 18014 was a German V-2 rocket test launch that took place on 20 June 1944, at the Peenemünde Army Research Center in Peenemünde. It was the first man-made object to reach outer space, attaining an apogee of 176 kilometers, which is well above the Kármán line. It was a vertical test launch. Although the rocket reached space, it did not reach orbital velocity, and therefore returned to Earth in an impact, becoming the first sub-orbital spaceflight.
First object in orbit
The first successful orbital launch was of the Soviet uncrewed Sputnik 1 (“Satellite 1”) mission on 4 October 1957. The satellite weighed about 83 kg (183 lb), and is believed to have orbited Earth at a height of about 250 km (160 mi). 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 3 January 1958.
First human outer space flight
The first successful human spaceflight was Vostok 1 (“East 1”), carrying the 27-year-old Russian cosmonaut, Yuri Gagarin, on 12 April 1961. The spacecraft completed one orbit around the globe, lasting about 1 hour and 48 minutes. Gagarin’s flight resonated around the world; it was a demonstration of the advanced Soviet space program and it opened an entirely new era in space exploration: human spaceflight.
First astronomical body space explorations
The first artificial object to reach another celestial body was Luna 2 reaching the Moon in 1959. The first soft landing on another celestial body was performed by Luna 9 landing on the Moon on 3 February 1966.Luna 10 became the first artificial satellite of the Moon, entering in a lunar orbit on 3 April 1966.
The first crewed landing on another celestial body was performed by Apollo 11 on 20 July 1969, landing on the Moon. There have been a total of six spacecraft with humans landing on the Moon starting from 1969 to the last human landing in 1972.
The first interplanetary flyby was the 1961 Venera 1 flyby of Venus, though the 1962 Mariner 2 was the first flyby of Venus to return data (closest approach 34,773 kilometers). Pioneer 6 was the first satellite to orbit the Sun, launched on 16 December 1965. The other planets were first flown by 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, 1989 for Neptune by Voyager 2. In 2015, the dwarf planets Ceres and Pluto were orbited by Dawn and passed by New Horizons, respectively. This accounts for flybys of each of the eight planets in the Solar System, the Sun, the Moon and Ceres & Pluto (2 of the 5 recognized dwarf planets).
The first interplanetary surface mission to return at least limited surface data from another planet was the 1970 landing of Venera 7, which returned data to Earth for 23 minutes from Venus. In 1975 the Venera 9 was the first to return images from the surface of another planet, returning images from Venus. 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 six years of Mars surface operation by Viking 1 from 1975 to 1982 and over two hours of transmission from the surface of Venus by Venera 13 in 1982, the longest ever Soviet planetary surface mission. Venus and Mars are the two planets outside of Earth on which humans have conducted surface missions with uncrewed robotic spacecraft.
First space station
Salyut 1 was the first space station of any kind, launched into low Earth orbit by the Soviet Union on 19 April 1971. The International Space Station is currently the only fully functional space station, inhabited continuously since the year 2000.
First interstellar space flight
Voyager 1 became the first human-made object to leave the Solar System into interstellar space on 25 August 2012. The probe passed the heliopause at 121 AU to enter interstellar space.
Farthest from Earth
The Apollo 13 flight passed the far side of the Moon at an altitude of 254 kilometers (158 miles; 137 nautical miles) above the lunar surface, and 400,171 km (248,655 mi) from Earth, marking the record for the farthest humans have ever traveled from Earth in 1970.
Voyager 1 is currently at a distance of 145.11 astronomical units (2.1708×1010 km; 1.3489×1010 mi) (21.708 billion kilometers; 13.489 billion miles) from Earth as of 1 January 2019.It is the most distant human-made object from Earth.
GN-z11 is the most distant known object from Earth, reported as 13.4 billion light-years away.