A sun-synchronous orbit is a circular, retrograde low-Earth orbit that is inclined 95 degrees to 105 degrees. Due to earth’s oblateness and a specific combination of high inclination and low altitude, the satellite’s ascending node moves eastward about 1 degree per day. Since the Earth also rotates around the Sun about 1 degree per day, the orbital plane of a sun-synchronous satellite will maintain the same orientation with respect to the sun.
Common Uses and Benefits: Ideal for remote-sensing missions. Passes over the same local times each day; sees similar light each day which is useful for remote imaging; a dawn-dusk orbit allows for constant solar panel lighting.