This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.
Space science is a term that is all-encompassing. It describes all of the various science fields that are concerned with the study of the Universe, generally also meaning "excluding the Earth" and "outside of the Earth's atmosphere". Originally, all of these fields were considered part of astronomy. However, in recent years the major sub-fields within astronomy, such as astrophysics, have grown so large that they are now considered separate fields on their own. There are eight overall categories that can generally be described on their own; Astrophysics, Galactic Science, Stellar Science, non-Earth Planetary Science, Biology of Other Planets, Astronautics/Space Travel, Space Colonization and Space Defense. The Library of congress and Dewey Decimal System have a major classification "Descriptive Astronomy" which they use instead of placing descriptive works into their huge "Geography" collections.
Physical space exploration is conducted by human spaceflights and robotic spacecraft. Observation of objects in space is known as astronomy. It predates reliable recorded history. It was the development of large and relatively efficient rockets during the early 20th century that allowed physical space exploration to become a reality. Some common rationales for exploring space are advancing scientific research, uniting different nations, ensuring the future survival of humanity and developing military and strategic advantages against other countries. Sometimes various criticisms of space exploration are made.
Focus shifted, after the first 20 years of exploration, 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). Since the 1990s, private interests began promoting space tourism and then private space exploration of the Moon itself.
German scientists took the first steps of putting a manmade object into space during WWII while testing the V2 rocket which became the first human-made object in space on October 3, 1942 with the launching of V-4. 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 were taken the same year while the first animal experiment saw fruit flies lifted into space in 1947, both also on modified V2s launched by Americans. These suborbital experiments only allowed a very short time in space which limited their usefulness.
Rocket technology pushed the dream of stepping into the outer reaches of the Earth's atmosphere even further. Overcoming the problems of thrust and material failure, the German V2 was the first rocket to travel into space. During the final days of World War II this technology was obtained by both the Americans and Soviets as were its designers. The initial driving force for further development of the technology was a weapons race for intercontinental ballistic missiles (ICBMs) to be used as long-range carriers for fast nuclear weapon delivery, but in 1961 when USSR launched the first man into space, the U.S. declared itself to be in a "space race" with Russia.
In 1990 the Hubble Space Telescope (HST) was carried into orbit by a space shuttle. Although not the first space telescope, Hubble is one of the largest and most versatile, and is well-known as both a vital research tool and a public relations boon for astronomy. The United States space agency NASA built the HST, with contributions from the European space agency and is operated by the space telescope science institute. It is named after the astronomer Edwin Hubble. The HST is one of NASA's Great Observatories, along with the Compton gamma ray observatory, the Chandra X-ray observatory, and the Spitzer space telescope.
Space telescopes were proposed as early as 1923. In the 1970s Hubble was funded, with a proposed launch in 1983, but the project was beset by technical delays, budget problems, and the Challenger disaster. In 1990 it was finally launched, scientists found that the main mirror had been ground incorrectly, severely compromising the telescope's capabilities. However, after a servicing mission in 1993, the telescope was restored to its intended quality. Hubble's orbit outside the distortion of earth's atmosphere allows it to take extremely sharp images with almost no background light. Hubble's ultra deep field image, for instance, is the most detailed visible-light image ever made of the universe's most distant objects. Many Hubble observations have led to breakthroughs in astrophysics, such as accurately determining the rate of expansion in the universe.
Hubble is the only telescope ever designed to be serviced in space by astronauts. Four servicing missions were performed from 1993 to 2002, but the fifth was cancelled on safety grounds following the space shuttle Columbia disaster. However, after spirited public discussion, NASA administrator Mike Griffin approved one final servicing mission, completed in 2009. The telescope is now expected to function until at least 2014, when its 'successor', the James Webb space telescope (JWST), is due to be launched.
Once the Space Telescope project had been given the go-ahead, work on the program was divided among many institutions. Marshall space flight center (MSFC) was given responsibility for the design, development, and construction of the telescope, while the Goddard space flight center was given overall control of the scientific instruments and ground-control center for the mission. MSFC commissioned the optics company Perkin-Elmer to design and build the Optical Telescope Assembly (OTA) and Fine Guidance Sensors for the space telescope. Lockheed was commissioned to construct and integrate the spacecraft in which the telescope would be housed.
The international space station (ISS) is an internationally developed research facility that is being assembled in low Earth orbit. On-orbit construction of the station began in 1998 and is scheduled for completion by late 2011. The station is expected to remain in operation until at least 2015, and likely 2020. With a greater cross-sectional area than that of any previous space station, the ISS can be seen from Earth with the naked eye, and is by far the largest artificial satellite that has ever orbited Earth. The ISS serves as a research laboratory that has a microgravity environment in which crews conduct experiments in biology, chemistry, medicine, physiology and physics, as well as astronomical and meteorological observations. The station provides a unique environment for the testing of the spacecraft systems that will be required for missions to the Moon and Mars. The ISS is operated by Expedition crews of six astronauts and cosmonauts, with the station programme maintaining an uninterrupted human presence in space since the launch of Expedition 1 on 31 October 2000, a total of 10 years and 4 days. The programme thus holds the current record for the longest uninterrupted human presence in space, surpassing the previous record of 3,644 days, set aboard Mir, on 25 October 2010. As of 25 September 2010, the crew of Expedition 25 is aboard.
The ISS is a synthesis of several space station projects that include the American Freedom, the Soviet/Russian Mir-2, the European Columbus and the Japanese Kibo. Budget constraints led to the merger of these projects into a single multi-national programme. The ISS project began in 1994 with the Shuttle-Mir programme, and the first module of the station, Zarva, was launched in 1998 by Russia. Assembly continues, as pressurised modules, external trusses, and other components are launched by American space shuttles, Russian Proton rockets and Russian Soyuz rockets. As of May 2010, the station consists of fourteen pressurised modules and an extensive integrated truss structure (ITS). Power is provided by sixteen solar arrays mounted on the external truss, in addition to four smaller arrays on the Russian modules. The station is maintained at an orbit between 278 km (173 mi) and 460 km (286 mi) altitude, and travels at an average speed of 27,743.8 km/h (17,239.2 mph), completing 15.7 orbits per day.
Operated as a joint project between the five participant space agencies, the station's sections are controlled by mission control centres on the ground operated by the American National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), the Russian Federal Space Agency (RKA), the Japan Aerospace Exploration Agency (JAXA) and the Canadian Space Agency (CSA). The ownership and use of the space station is established in intergovernmental treaties and agreements that allow the Russian Federation to retain full ownership of its own modules in the Russian Orbital Segment, with the US Orbital Segment, the remainder of the station, allocated between the other international partners. The cost of the station has been estimated by ESA as â‚¬100 billion over 30 years, and, although estimates range from 35-160 billion US dollars, the ISS is believed to be the most expensive object ever constructed. The financing, research capabilities and technical design of the ISS programme have been criticised because of the high cost. The station is serviced by Soyuz spacecraft, Progress spacecraft, space shuttles, the Automated Transfer Vehicle and the H-II Transfer Vehicle, and has been visited by astronauts and cosmonauts from 15 different nations.
The Space Shuttle, part of the Space Transportation System (STS), is an American spacecraft operated by the National Aeronautics and Space Administration (NASA) for orbital human spaceflight missions. The first of four test flights occurred in 1981, which were followed by operational flights beginning in 1982. The system is scheduled to be retired from service in 2011 after 135 launches. Major missions have included launching numerous satellites and interplanetary probes, conducting space science experiments, and servicing and construction of space stations. The Shuttle has been used for orbital space missions by NASA, the U.S. Department of Defense, the European Space Agency, and Germany. The United States funded STS development and shuttle operations.
At launch, the Space Shuttle consists of the shuttle stack which includes a dark orange-colored external tank (ET, holds fuel) two white, slender Solid Rocket Boosters (SRBs) and the STS Orbiter Vehicle (OV) which contains the crew and payload. The ET was painted white for the first 2 missions, but was discontinued to save weight. Payloads can be launched into higher orbits with either of two different booster stages developed for the STS (1 stage Payload Assist Module or 2 stage Inertial Upper Stage). The Space Shuttle is stacked in the Vehicle Assembly Building and the stack mounted on a mobile launch platform held down by four explosive bolts on each SRB which are detonated at launch.
The shuttle stack launches vertically, like a conventional rocket, from a mobile launch platform (the platform it launches from can move around so they can launch from different facilities without having to take off the shuttle). It lifts off under the power of its two SRBs and the three main engines which are fuelled by liquid hydrogen and liquid oxygen from the external tank. The Space Shuttle has a two stage ascent. The SRBs provide additional thrust during liftoff and first stage flight. About two minutes after liftoff explosive bolts are fired releasing the SRBs which parachute into the ocean to be retrieved by ships for refurbishment and reuse. The shuttle orbiter and external tank continue to ascend on an increasingly horizontal flight path under power from the three main engines. Reaching 17,500 mph, necessary for low Earth orbit, the main engines are shut down. The external tank is then jettisoned downward to burn up in the atmosphere. It is, however, possible for the external tank to be re-used in orbit. After jettisoning the external tank, the orbital maneuvering system (OMS) engines may be used to adjust the orbit.
The orbiter carries astronauts and payload such as satellites or space station parts into low earth orbit, into the Earth's upper atmosphere or thermosphere. Usually, five to seven crew members ride in the orbiter. Two crew members, the Commander and Pilot, are sufficient for a minimal flight, as in the first four "test" flights, STS-1 through STS-4. A typical payload capacity is about 22,700 kilograms (50,000 lb, wow!), but can be raised depending on the choice of launch configuration. The orbiter carries the payload in a large cargo bay with doors that open along the length of its top, a feature which makes the Space Shuttle unique among present spacecraft. This feature made possible the deployment of large satellites such as the Hubble Space Telescope, and also to capture and return large payloads back to Earth.
When the orbiter's space mission is complete it fires its OMS thrusters to drop out of orbit and re-enter the lower atmosphere. During the descent, the shuttle orbiter passes through different layers of the atmosphere and decelerates from hypersonic speed primarily by aerobraking. In the lower atmosphere and landing phase, it acts as a glider with reaction control system (RCS) thrusters and fly-by wire controlled hydraulically actuated flight surfaces controlling its descent. It then makes a landing on a long runway as a space plane. The aerodynamic shape is a compromise between the demands of radically different speeds and air pressures during re-entry, subsonic atmospheric flight, and hypersonic flight. As a result the orbiter has a high sink rate at low altitudes, and transitions from using RCS thrusters in low pressure to flight surfaces at low altitudes.
The National Aeronautics and Space Administration (NASA) is an Executive Branch agency of the United States government, responsible for the nation's civilian space program and aeronautics and aerospace research. Since February 2006, NASA's self-described mission statement is to "pioneer the future in space exploration, scientific discovery and aeronautics research."
NASA was established by the National Aeronautics and Space Act on July 29, 1958, replacing its predecessor, the National Advisory Committee for Aeronautics (NACA). The agency became operational on October 1, 1958. NASA has led U.S. efforts for space exploration since, including the Apollo moon-landing missions, the Skylab space station, and later the Space Shuttle. Currently, NASA is supporting the International Space Station and has been developing the manned Orion spacecraft.
NASA science is focused on better understanding Earth through the Earth Observing System, advancing heliophysics (not sure what this is) through the efforts of the Science Mission Directorate's Heliophysics Research Program, exploring bodies throughout the Solar System with advanced robotic missions such as New Horizons, and researching astrophysics topics, such as the Big Bang, through the Great Observatories and associated programs. NASA shares data with various national and international organizations such as from the Greenhouse Gases Observing Satellite.
Space goes on forever therefore it is impossible for scientists to study and explore the whole thing but as the years go by and technology improves greatly, we will be able to keep exploring further and further into space. Scientists are currently studying the moon and when global warming gets to extreme we may be able to move to the moon in the future, but for now it's all a dream.
NASA's website (www.nasa.gov )
Space exploration (book)
Some other random unknown sites from Google
Notes taken from resources and summarized
Online interactive book from a book order