| Space Station |
Article Index for Space Station |
Articles about Space Station |
Website Links For Space Station |
Information AboutSpace Station |
| CATEGORIES ABOUT SPACE STATION | |
| space stations | |
| shelters | |
|
A space station is an artificial structure designed for Human s 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 Week s, Month s, or even Year s. The only space station currently in use is the International Space Station . Space stations are currently (as of 2007) 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 2006 , three astronauts have completed single missions of over a year, all aboard Mir. USES Space stations have been used for both military and civilian purposes. The last military-use space station was TYPES OF SPACE STATION "Monolithic" 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 Salyut 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 in 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. Modular 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. HABITABILITY ISSUES These stations have various issues that limit their long-term habitability, such as very low recycling rates, relatively 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, all current habitats are protected by the Earth's magnetic field, and are below the Van Allen Belts . Future Space Habitat s may attempt to 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 (2007) launch costs. Possible ways to deal with these costs would be building lots of rockets (economies of scale), reusable rockets, In Situ Resource Utilisation or if Space Elevator s are ever able to be constructed. PAST AND PRESENT SPACE STATIONS ''(dates refer to periods when stations were inhabited by crews)''
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 occupied since October 30 , 2000 . As of 9 September , 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 Ton s (202.1 Short Ton s). List of occupied space stations, with statistics Crew and visitors counting is non-distinct.
CANCELED SPACE STATIONS
FUTURE DEVELOPMENTS
REFERENCES SEE ALSO EXTERNAL LINKS
|
|
|