[Why Use a Polar Orbit?] [Inclinations]

Polar Orbit A Polar orbit is a particular type of Low Earth Orbit. The only difference is that a satellite in polar orbit travels a north-south direction, rather than the more common east-west direction.

Why use a Polar Orbit? Polar orbits are useful for viewing the planet's surface. As a satellite orbits in a north-south direction, Earth spins beneath it in an east-west direction. As a result, a satellite in polar orbit can eventually scan the the entire surface. Its like pealing an orange in one piece. Around and around, one strip at a time, and finally you've got it all. For this reason, satellites that monitor the global environment, like remote sensing satellites and certain weather satellites, are almost always in polar orbit. No other orbit gives such thorough coverage of Earth.

Inclinations We say that a polar orbit has an inclination, or angle, of 90 degrees. It is perpendicular to an imaginary line that slices through Earth at the equator.