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.
The actual satellite orbit that is chosen will depend on factors including its function, and the area it is to serve. In some instances the satellite orbit may be as low as 100 miles (160 km) for a Low Earth Orbit LEO, whereas others may be over 22 000 miles (36000 km) high as in the case of a GEostationary Orbit GEO.The satellite may even have an elliptical rather than a circular orbit. This is generally taken to be 3960 miles or 6370 km. 2  Orbit velocity: For a circular orbit it is always the same. 3  However in the case of an elliptical one this is not the case as the speed changes dependent upon the position in the orbit.