Applications of Space stations
Observing and researching earth's surface - The tiniest detail on the earth's surface can be detected from the space station with the help of powerful telescopes. Optical signals are used as a medium of transmission between the space station and earth. Space stations help in exploring lands, determining soil type, obtaining information about inhabitation and accessibility.
Remote photography can be employed not only to picture entire countries or continents but also to obtain a detailed map of any scale. Important marine routes could be kept under surveillance to warn the ships of impending danger.
Movement of clouds on more than one-third of the entire earth surface can be surveyed and celestial observations not possible from the earth can be performed.
Using telescopes of enormous sizes - Due to the absence of atmosphere in space, there is no optical barrier for using telescopes. From the point of view of construction, large telescopes can be used due to weightlessness. The electrical power necessary for controlling these instruments is available from the space stations.
Exploring the stars - The radiation from the star arrives completely unweakened and undistorted. Because of these advantages, space station provides exciting prospects for astronomy.
The entire solar system comprising of the planets, moons, comets… can be studied. The surfaces of all the nearby celestial bodies can be topographically mapped by remote photography.
Giant floating mirror - These mirrors consist of individual segments portable in such a way that they can be oriented in any arbitrary direction. The individual segments are attached to a wire mesh comprising of paper-thin sodium foils. By properly aligning the mirrors it is possible to concentrate the entire sun's energy on a single point on earth or spread over wide regions of the earth's surface.
The electrical energy required to operate the mirror can be made available from the space station.
Using very large space mirrors in the northern region the sea-lanes can be kept free of ice. It can also be used to overcome sudden drops in temperature and pressure, hailstorms, frosts etc.
Space mirrors can became a dangerous weapon when large amount of heat is generated by space mirror. If this heat were concentrated on enemy's ammunition, tanks, cannons, it would ignite all his war material.
The space station acts as a base for travel into deep space - Space station provides a repository for spacecrafts traveling into deep space. If the spacecraft began its journey from the space station it will have to be loaded with only a little more propellant than that required for the deep space trip.
Since the space station is in a state of weightlessness due to its orbital motion, the propellants can be stored for infinite period. Propellants can be resupplied from the earth by a shuttle ship service.
As we now have an idea about the requirements and applications of the space station. Let us proceed further and have a look at the different space stations, which were launched.
Salyut space station placed in orbit by Russia in 1971
Space station Skylab launched by USA in 1973
Space station Mir launched by Russia in 1986
International space station launched on 31 October 2000
In the next section, working of each space station, various missions sent and the experiments conducted are discussed.