|
In celestial mechanics, the term stationary orbit refers to an orbit around a planet or moon where the orbiting satellite or spacecraft remains orbiting over the same spot on the surface. From the ground, the satellite would appear to be standing still, hovering above the surface in the same spot, day after day.〔 "Space Today Online - Answers To Your Questions", Spacetoday.org, 2010, webpage: (ST-Sats ). 〕 In practice, this is accomplished by matching the rotation of the surface below, by reaching a particular altitude where the orbital speed almost matches the rotation below, in an equatorial orbit.〔 As the speed decreases slowly, then an additional boost would be needed to increase the speed back to a matching speed, or a retro-rocket could be fired to slow the speed when too fast. The stationary-orbit region of space is known as the Clarke Belt, named after British science fiction writer Arthur C. Clarke, who published the idea in ''Wireless World'' magazine in 1945.〔 A stationary orbit is sometimes referred to as a "fixed orbit". ==Stationary Earth orbit== (詳細はEarth, stationary satellites orbit at altitudes of approximately .〔 Writing in 1945, the science-fiction author Arthur C. Clarke imagined communications satellites as travelling in stationary orbits, where those satellites would travel around the Earth at the same speed the globe is spinning, making them hover stationary over one spot on the Earth's surface.〔 A satellite being propelled into place, into a stationary orbit, is first fired to a special equatorial orbit called a "geostationary transfer orbit" (GTO).〔 Within this oval-shaped (elliptical) orbit, the satellite will alternately swing out to high and then back down to an altitude of only above the Earth (223 times closer). Then, at a planned time and place, an attached "kick motor" will push the satellite out to maintain an even, circular orbit at the 22,300-mile altitude.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Stationary orbit」の詳細全文を読む スポンサード リンク
|