Placing a satellite into terrestrial polar orbit demands more energy, and therefore more propellant, than does achieving a direct orbit of low inclination. In the latter case, the launch normally takes place near the equator, where the rotational speed of the surface contributes a significant part of the final speed needed for orbit. Since a polar orbit is not able to take advantage of the free ride provided by Earth's rotation, the launch vehicle must provide all of the energy for attaining orbital speed.
Related entry sun-synchronous orbit
Related category• CELESTIAL MECHANICS
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