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Space station

2007 Schools Wikipedia Selection. Related subjects: Space transport

   The International Space Station in 2006
   Enlarge
   The International Space Station in 2006
   Computer-generated image of the completed International Space Station
   Enlarge
   Computer-generated image of the completed International Space Station

   A space station is an artificial structure designed for humans to live
   in outer space. So far only low earth orbit (LEO) stations are
   implemented, also known as orbital stations. A space station is
   distinguished from other manned spacecraft by its lack of major
   propulsion or landing facilities — instead, other vehicles are used as
   transport to and from the station. Space stations are designed for
   medium-term living in orbit, for periods of weeks, months, or even
   years.

   Space stations are used to study the effects of long-term space flight
   on the human body as well as to provide platforms for greater number
   and length of scientific studies than available on other space
   vehicles. Since the ill-fated flight of Soyuz 11 to Salyut 1, all
   manned spaceflight duration records have been set aboard space
   stations. The duration record of 437.7 days was set by Valeriy Polyakov
   aboard Mir from 1994 to 1995. As of 2005, 3 astronauts have completed
   single missions of over a year, all aboard Mir.

Past and present space stations

   The space station Mir
   Enlarge
   The space station Mir
     * Salyut stations: Salyut 1, Salyut 2 (failed on-orbit, never
       occupied), Salyut 3, Salyut 4, Salyut 5, Salyut 6, Salyut 7
     * Skylab
     * Mir
     * International Space Station (ISS)

   Following the controlled deorbiting of Mir in 2001, the International
   Space Station is the only one of these currently in orbit; it has been
   continuously manned since October 30, 2000. As of 9 Sept 2006, it was
   44.5 metres (146 ft) in length along the core between the Destiny and
   Zvezda modules or 52 metres (171 ft) long when a Progress is attached,
   and has a mass of 183.3 metric tons (202.1 short tons).

   A second Skylab unit (Skylab B) was manufactured, as a backup article;
   due to the high costs of providing launch vehicles, and a desire by
   NASA to cease Saturn & Apollo operations in time to prepare for the
   Space Shuttle coming into service, it was never flown. The hull can now
   be seen in the National Air and Space Museum, in Washington DC, where
   it is a popular tourist attraction. A number of additional Salyuts were
   also produced, as backups or as flight articles which were later
   cancelled.

   The International Space Station evolved from the American Space Station
   Freedom program, which - despite being under development for ten years
   - was never launched; it incorporated elements of a Mir replacement
   station ("Mir 2") which was also never constructed. Other cancelled
   space station programs included the United States Air Force Manned
   Orbiting Laboratory project, cancelled in 1969 about a year before the
   first planned test flight; this was unusual in being an explicitly
   military project, as opposed to the Soviet Almaz program, which was
   heavily intertwined with - and concealed by - the contemporaneous
   Salyut program.

   Currently, Bigelow Aerospace is commercially developing inflatable
   habitat modules, derived from the earlier Transhab concept, intended to
   be used for space station construction and for a space prize they are
   funding and operating, America's Space Prize. Genesis-1 is a ⅓-scale
   unmanned prototype sent up to test the feasibility of inflatable
   structures and other systems in space.

Types of space station

   Broadly speaking, the space stations so far launched have been of two
   types; the earlier stations, Salyut and Skylab, have been "monolithic",
   intended to be constructed and launched in one piece, and then manned
   by a crew later. As such, they generally contained all their supplies
   and experimental equipment when launched, and were considered
   "expended", and then abandoned, when these were used up.

   Starting with Salyut 6 and 7, a change was seen; these were built with
   two docking ports, which allowed a second crew to visit, bringing a new
   spacecraft (for technical reasons, a Soyuz capsule cannot spend more
   than a few months on orbit, even powered down, safely) with them. This
   allowed for a crew to man the station continually. The presence of a
   second port also allowed Progress supply vehicles to be docked to the
   station, meaning that fresh supplies could be brought to aid
   long-duration missions. This concept was expanded on Salyut 7, which
   "hard docked" with a TKS tug shortly before it was abandoned; this
   served as a proof-of-concept for the use of modular space stations. The
   later Salyuts may reasonably be seen as a transition between the two
   groups.

   The second group, Mir and the ISS, have been modular; a core unit was
   launched, and additional modules, generally with a specific role, were
   later added to that. (On Mir they were usually launched independently,
   whereas on the ISS most are brought by the Shuttle). This method allows
   for greater flexibility in operation, as well as removing the need for
   a single immensely powerful launch vehicle. These stations are also
   designed from the outset to have their supplies provided by logistical
   support, which allows for a longer lifetime at the cost of requiring
   regular support launches.

   These stations have various issues that limit their long-term
   habitability, such as very low recycling rates, high radiation levels
   and a lack of gravity. Some of these problems cause discomfort and
   long-term health effects. In the case of solar flares, most current
   habitats even have an acute danger of radiation poisoning. Some space
   habitats address these issues, and are intended for long-term
   occupation. Some designs might even accommodate large numbers of
   people, essentially "cities in space" where people would make their
   homes. No such design has yet been constructed, because even for a
   small station, the extra equipment is too expensive to place in orbit
   at current (2006) launch costs.

List of occupied space stations, with statistics

   Space station Image Launched Reentered Days in use Total crew
   and visitors Visits Mass
   ( kg)
   In orbit Occupied Manned Unmanned
   Salyut 1 Apr 19, 1971
   01:40:00 UTC Oct 11, 1971 175 24 3 2 0 18,425
   Skylab May 14, 1973
   17:30:00 UTC Jul 11, 1979
   16:37:00 UTC 2,249 171 9 3 0 77,088
   Salyut 3 Jun 25, 1974
   22:38:00 UTC Jan 24, 1975 213 15 2 1 0 18,500
   Salyut 4 Dec 26, 1974
   04:15:00 UTC Feb 3, 1977 770 92 4 2 1 18,500
   Salyut 5 Jun 22, 1976
   18:04:00 UTC Aug 8, 1977 412 67 4 2 0 19,000
   Salyut 6 Sep 29, 1977
   06:50:00 UTC Jul 29, 1982 1,764 683 33 16 14 19,000
   Salyut 7 Apr 19, 1982
   19:45:00 UTC Feb 7, 1991 3,216 816 26 12 15 19,000
   Mir Feb 19, 1986
   21:28:23 UTC Mar 23, 2001
   05:50:00 UTC 5,511 4,594 137 39 68 124,340
   ISS Nov 20, 1998 2025**** **2,898 **2,185 ***153 ***32 ***25 **454,240
   (206,040 kg)

   Crew and visitors counting is non-distinct.
     * **ISS stats as of October 27, 2006.
     * ***ISS stats as of October 27, 2006.[19 shuttles, 13 Soyuz, 1 Soyuz
       - Assembly, 22 Progress, 2 Proton and Pirs]
     * ****Predicted ISS reentry

Part of space elevator

   This article contains speculation and may try to argue its points.
   Information must be verifiable and based on reliable published sources.
   Please remove speculation and discussion from the article.

   A space station can be the counterweight part of a space elevator, as
   well as being placed at some point of the cable, like 35786 km to have
   microgravity conditions. In this case, another station (or an asteroid,
   or anything with enough mass) would be needed as a counterweight.

In fiction

   A large amount of science fiction is set on space stations:
     * Venus Equilateral Relay Station, from the 1940s Venus Equilateral
       series by George O. Smith, was a communications hub set in Venus'
       L[4] point.

     * The Chesley Bonestell station design of the '50s was a 250 ft
       diameter, 3-deck wheel that revolved at 3 RPM to provide artificial
       one-third gravity.

     * The Star Trek series has several types of stations. Federation Deep
       Space Station K-7 was featured in a planetary dispute and Earth
       Station McKinley acted as a shipbuilding/repair facility.

     * Similarly, Deep Space 9 is a prominent space station in the Star
       Trek story line. It was built by the Cardassians around Bajor and
       later staffed by Federation personnel.

     * In Stargate Atlantis, a "stargate bridge" links the Milky Way and
       Pegasus galaxies. Because there are differences between the Milky
       Way and Pegasus Stargates, there is a space station linking the two
       systems at the midpoint. As of the episode The Return, the space
       station is incomplete and is, in fact, little more than a wire
       frame holding two Stargates.

     * The film (and novel) 2001: A Space Odyssey has Space Station 5,
       built as an 1836 ft partially completed double ring, revolving to
       produce one-sixth gravity; this has proven to be one of the iconic
       images of a space station in popular culture.

     * The James Bond film Moonraker featured a space station which serves
       as Hugo Drax's lair and a base to attack earth using nerve gas.

     * The Babylon 5 television series is set on a space station by that
       name in the years of 2258-2262.

     * In the Gundam series of anime, most of the human race lives in
       space stations.

   Retrieved from " http://en.wikipedia.org/wiki/Space_station"
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