jump to other results. 1  1[countable] a particular attitude towards something; a way of thinking about something synonym viewpoint a global perspective Recent events seem less serious when put into an international perspective.
Low earth orbit is only slightly above the Earth, by outer space standards, 124 - 1240 miles (200 - 2000 km) in altitude. Below 124 miles, orbits rapidly degrade, causing surface impact, and above 1,240 miles or even less, the Earth's radiation belts damage electronic equipment, necessitating special shielding. The region from 1,243 miles altitude to geostationary orbit (35,786 kilometers or 22,236 mi) is known as Medium Earth Orbit.
Two medium Earth orbits are notable: the semi-synchronous orbit and the Molniya orbit. The semi-synchronous orbit is a near-circular orbit (low eccentricity) 26,560 kilometers from the center of the Earth (about 20,200 kilometers above the surface). A satellite at this height takes 12 hours to complete an orbit.his special, high Earth orbit is called geosynchronous. A satellite in a circular geosynchronous orbit directly over the equator (eccentricity and inclination at zero) will have a geostationary orbit that does not move at all relative to the ground.