Space exploration
From Free net encyclopedia
Space exploration is the physical exploration of outer space objects and generally anything that involves the technologies, science, and politics regarding space endeavors.
It was given a boost by the launch of Sputnik 1, the first man-made object to orbit the Earth, which set off the space race between the United States and the Soviet Union. On October 5, 1957, the USSR launched Sputnik 1, the first man-made object to orbit the Earth. Two other famous achievements in the early days were putting the first man in space, Yuri Gagarin aboard Vostok 1 on April 12, 1961 (again by the USSR), and the first people on the Moon, Neil Armstrong and Buzz Aldrin aboard Apollo 11 with Michael Collins (by the USA). After 30 years of competition focus has started shifting from competition to cooperation and from one-off flights to renewable hardware, such as the Space Shuttle (which was later cancelled due to low reliability - see Space Shuttle disasters), to autonomous shuttles Buran, to the International Space Station, to space tourism and most recently to the building of extra-terrestrial launch platforms, such as from a space station and possibly from the Moon.
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Reaching space
From a spaceflight perspective, the definition of space usually used is that space begins 100 km (62 miles) above Earth's surface. The United States sometimes uses a 50 mile definition. (See boundary to space.)
One can distinguish the sub-orbital spaceflight and the orbital spaceflight (cf. Difference between sub-orbital and orbital spaceflights). As for sub-orbital flights, on October 3, 1942 German A4 rocket (a prototype for the next V2 rocket used to bomb London), became the first successful launch of an object into space. The first organisms launched into space were fruit flies and corn seeds aboard a U.S.-launched german V2 rocket in July, 1946. Another milestone was achieved on May 17, 2004 when Civilian Space eXploration Team launched the GoFast Rocket on a suborbital flight, the first amateur space flight. On June 21, 2004, SpaceShipOne became the first privately-funded manned spacecraft.
Achieving orbit is not essential for manned or unmanned interplanetary voyages. Early russian space vehicles successfully achieved very high altitudes without even going into orbit. The early Apollo mission planning also considered using a direct ascent to the moon, but abandoned it later. Many unmanned space probes to the outer planets use direct ascent -- they do not orbit the earth before departing.
However, plans for future manned exploration often include final vehicle assembly in earth orbit.
Because suborbital flights are by definition short (less than 1.7 hours) then any longer mission requires orbital flight (with elliptical or circular trajectory), or superorbital flight (over parabolic or hyperbolic trajectory). Also, orbital flight requires much higher velocities than suborbital making it technologically challenging to achieve.
That is why orbital flights are so tremendousely essential for space exploration.
First orbital flights
The first successful orbital launch was of the Soviet unmanned Sputnik I mission on October 4, 1957. The satellite weighed about 83 kg (184 pounds). It had two radio transmitters (20 and 40 MHz) "beeps" of which can be heard by any radio around the globe and is believed to have orbited Earth at a height of about 250 km (150 miles). Analysis of the radio signals was used to gather information about the electron density of the ionosphere. Temperature and pressure was encoded in the duration of radio beeps, indicating the satellite was not punctured by a meteorite. Sputnik 1 was launched by an R-7 rocket. It incinerated upon re-entry on January 3, 1958.
This success led to an escalation of the American space program which had an unsuccessful orbital launch 2 months later and its first successful orbital launch 4 months after Sputnik. In the meantime, Soviet dog Laika became the first animal in orbit on November 3, 1957.
First human in space
First flight in space made by a human being was Vostok 1, carrying 27 year old cosmonaut Yuri Gagarin on historic date of April 12 1961 around the globe. Currently this milestone date is celebrated as Cosmonautics Day (Space Day).
Gagarin's flight resonated around the globe not only showing superiority of Soviet space program but opening entirely new era in space exploration - manned space flights. The U.S. would launch its first man into space within a month of Gagarin's flight; however, it took the U.S. nearly a full year to place a man into orbit.
The key people in early space exploration
The dream of stepping into the outer reaches of the Earth's atmosphere was driven by rocket technology. The German V2 was the first rocket to travel into space, overcoming the problems of thrust and material failure. 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 was a weapons race for inter-continental ballistic missiles ICBM as long-range carriers for fast nuclear weapon delivery, but in 1961 when USSR launched first man into space, USA declared itself to be in the "Space Race" with Russia.
- Konstantin Tsiolkovsky, Robert Goddard, Hermann Oberth and Reinhold Tilling laid the groundwork of rocketry in the early years of the 20th century.
- Wernher von Braun was lead rocket nazi engineer for Germany's World War II V-2 project. After the war he (along with many other nazi rocket scientists and even V-2 rocket itself) was secretly brought to USA to work on US space program. He took American citizenship and led the team to orbit Explorer I, the first American satellite. Von Braun led the team at NASA's Marshall Space Flight Center which developed the Saturn V moon rocket.
- Initially the race for space was often led by Sergei Korolev, whose legacy include both the R7 and Soyuz - which remain in service to this day. Korolev was the mastermind behind the first satellite, first man (and first woman) in orbit and first spacewalk. Until his death his identity was closely guarded state secret, not even his mother knew that he was responsible for creating the Russian space programm.
Other key people included:
- Valentin Glushko held role of Chief Engine Designer for USSR. Glushko designed the engines of the early Soviet rockets.
- Vasily Mishin, Chief Designer working under Sergei Korolev and one of first Soviets to inspect the captured German V2 design. Following the death of Sergei Korolev, Mishin was held responsible for the Soviet failure to be first country to place a man on the moon.
- Bob Gilruth, was NASA head of Space Task Force and director of 25 manned space flights. Gilruth was the person who suggested to John F. Kennedy that the Americans take the bold step of reaching the Moon in an attempt to reclaim space superiority from the Soviets.
- Christopher C. Kraft, Jr., was NASA's first flight director and oversaw development of Mission Control and associated technologies and procedures.
In the month April 1961 a man parachuted into a village of Smelovaka in Russia.Two farmers standing nearby asked him "Have you come from outer space?" And with a big grin and smile of pure joy he replied, " Yes,yes, would you believe it, I certainly have."
The fight had really then began between the Russians and Americans and the race to the climax of science was on!! In NASA John Glen of the space mission Mercury 7 said, "They beat the pants off us, thats all. There's no kidding ourselves about that."
Criticisms
It is more expensive to perform certain tasks in space with humans rather than by robots or machines. Humans need large spacecraft that contain provisions such as a hermetic and temperature controlled cabin, production of breathable air, food and drink storage, waste disposal, voice- and other communication systems, and safety features such as crew escape systems, medical facilities, etc. There is also the question of the security of the spacecraft as whole; losing a robot is nowhere near as dramatic as human loss, so overall safety of non-human missions isn't as much of an issue. All of these extra expenses have to be weighed against the value of having humans aboard. Some critics argue that those few instances where human intervention is essential do not justify the enormous extra costs of having humans aboard.
Other critics, such as the late physicist and Nobel-prize winner Richard Feynman, have contended that space travel has never achieved any major scientific breakthroughs. However, others counter-argued that there have been many indirect scientific achievements: development of the modern computer, lasers, etc.
Some critics contend that in light of the huge distances in space, human space travel will never be able to do more than achieve an earth orbit or at best visit our closest neighbours in the solar system, and even this will consume large amounts of money and will require complex spacecraft that will accommodate only a handful of people. Supporters of human space travel state that this is irrelevant, because its real value lies in providing a focal point for national prestige and patriotism. They suggest that this was the reason why the Clinton administration cooperated closely with Russia on the International Space Station: it gave Russia something to take pride in, and as such became a stabilizing factor in post-communist Russia. From this point of view, the ISS was a justifiable cash outlay.
Some people also have moral objections to the huge costs of space travel, and point out that even a fraction of the space travel budget would make a huge difference in fighting disease and hunger in the world. However, space exploration itself receives a very small percentage of total government spending (nearly always under 0.5%).
Overall, the public remains largely supportive of both manned and unmanned space exploration. According to an Associated Press Poll conducted in July 2003, 71% of US citizens agreed with the statement that the space program is "a good investment," compared to 21% who did not (Pollingreport.com).
Some supporters of Space Explorations, such as Robert Zubrin, have criticized ideas about in orbit assemblies, and argues for a direct approach for human settlement of Mars called Mars Direct.
Timeline of space exploration
Template:See also Timeline of planetary exploration, Timeline of solar system exploration, Timeline of artificial satellites and space probes, Spaceflight records
1942-1975
1Project Vanguard was transferred from the NRL to NASA immediately before launch.
2 The Soviet Union had attempted an earlier rendezvous on August 12, 1962; However, Vostok 3 and Vostok 4 were only within five kilometers of one another, and were in different orbital planes. Pravda, however, did not mention this information and indicated that rendezvous had been accomplished.
post-1975
| Date | First Success | Country | Mission Name |
|---|---|---|---|
| October 2 1978 | Non-American and non-Soviet in space | Image:Flag of the Soviet Union.svg USSR | Soyuz 28 |
| April 12 1981 | Reusable manned spacecraft | Image:Flag of the United States.svg USA-NASA | STS-1 |
| June 13 1983 | Extra-solar system spacecraft | Image:Flag of the United States.svg USA-NASA | Pioneer 10 |
| November 15 1988 | Reusable unmanned spacecraft | Image:Flag of the Soviet Union.svg USSR | Buran |
| July 7 1998 | Satellite launched from submarine | Image:Flag of Russia.svg Russia | K-407 |
| April 28 2001 | Space tourist | Image:Flag of Russia.svg Russia Image:Flag of the United States.svg USA | Soyuz TM-32 |
| June 21 2004 | Privately developed manned spacecraft | Image:Flag of the United States.svg USA-MAV | SpaceShipOne 15P |
Reusable spacecraft
The first reusable spacecraft, the Space Shuttle, was launched by the USA on the 20th anniversary of Yuri Gagarin's flight, on April 12, 1981. During the Shuttle era, six orbiters were built, all of which have flown in the atmosphere and five of which have flown in space. The Enterprise was used only for approach and landing tests, launching from the back of a Boeing 747 and gliding to deadstick landings at Edwards AFB, California. The first Space Shuttle to fly into space was the Columbia, followed by the Challenger, Discovery, Atlantis, and Endeavour. The Endeavour was built to replace the Challenger when it was lost in January 1986. The Columbia broke up during reentry in February 2003.
The first (and so far only) automatic reusable spacecraft was the Buran (Snowstorm), launched by the USSR on November 15, 1988, although it made only one flight. This spaceplane was designed for a crew and strongly resembled the U.S. Space Shuttle, although its drop-off boosters used liquid propellants and its main engines were located at the base of what would be the external tank in the American Shuttle. Lack of funding, complicated by the dissolution of the USSR, prevented any further flights of Buran.
Per the Vision for Space Exploration, the Space Shuttle is due to be retired in 2010. The orbiter Atlantis (Space Shuttle) may be retired as early as 2008. The Shuttle's human transport role is to be replaced by the partially reusable Crew Exploration Vehicle (CEV) no later than 2014. The Shuttle's heavy cargo transport role is to be replaced by expendable rockets such as the Evolved Expendable Launch Vehicle (EELV) or a Shuttle Derived Launch Vehicle.
Scaled Composites SpaceShipOne was a reusable suborbital spaceplane that carried pilots Mike Melvill and Brian Binnie on consecutive flights in 2004 to win the Ansari X Prize. The Spaceship Company will build its successor SpaceShipTwo. A fleet of SpaceShipTwos operated by Virgin Galactic should begin reusable private spaceflight carrying paying passengers in 2008.
Space agencies
While only the United States, Soviet Union/Russian and Chinese space programs have launched humans into orbit, a number of other countries have space agencies which design and launch satellites, conduct space research and coordinate national astronaut programs. In Europe, the European Space Agency serves several nations. Several nations have launched their own satellites including India, Japan and France.
See also List of space agencies
See also
Template:Spaceflight portal Template:Commons
Unmanned missions
Main article: Unmanned space mission
- Pioneer program
- Luna program
- Zond program
- Venera program
- Mars probe program
- Ranger program
- Mariner program
- Surveyor program
- Viking program
- Voyager program
- Vega program
- Phobos program
- Discovery program
Animals in space
Humans in space
Main articles: Astronauts and human spaceflight
- List of human spaceflights
- List of human spaceflights chronologically
- List of human spaceflights by program
- Vostok program
- Mercury program
- Voskhod program
- Gemini program
- Soyuz program
- Apollo program
- Salyut program
- Skylab
- Space Shuttle program
- Mir
- International Space Station
- Shenzhou spacecraft
- Vision for Space Exploration
- Aurora Programme
- Tier One
- Human adaptation to space
Recent and future developments
- Crew Exploration Vehicle
- Exploration of Mars
- Future energy development
- Space tourism
- Private spaceflight
- Space colonization
- Interstellar spaceflight
Other
- Atmospheric reentry
- Space station
- Space and survival
- Space disasters
- Space mathematics
- List of artificial objects on extra-terrestrial surfaces
- List of scheduled rocket launches
External links
- http://www.space.gs Space and Astronautics News
- http://www.federalspace.ru/
- http://www.russianspaceweb.com/
- http://space.skyrocket.de/
- http://www.planet4589.org/space/
- http://www.nasa.gov
- http://www.spacefacts.de
- http://www.vastbeyond.com
- http://www.space.com
- http://www.spacelist.org
- Universe Today - space news from around the Internet
- National Space Society - non-profit organization that promotes a spacefaring civilization
- Recent Developments In Space Exploration
- Benefits of Space Exploration - bibliography fom NASA.gov
- Technology Spinoffs from Space Exploration - NASA.gov
- 20 minute video essay on space exploration
- Planet Surveyor
- Aerospace Research Institute,IRAN, Persian Language [پژوهشگاه هوافضا]
- Space Science, Persian Language [دانش فضايي]
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