Editing Inclined orbit (section)

== Types of inclined orbits ==

=== Geosynchronous orbits ===
{{See also|Geosynchronous orbit}}
A geosynchronous orbit is an inclined orbit with an altitude of {{convert|37,000|km|mi|abbr=on}} that completes one revolution every [[sidereal day]] tracing out a small [[analemma|figure-eight shape]] in the sky.<ref>[https://celestrak.com/columns/v04n07/ Basics of the Geostationary Orbit By Dr. T.S. Kelso]</ref> A [[geostationary orbit]] is a special case of geosynchronous orbit with no inclination, and therefore no apparent movement across the sky from a fixed observation point on the Earth's surface.

Due to their inherent instability, geostationary orbits will eventually become inclined if they are not [[Orbital station-keeping|corrected]] using thrusters. At the end of the satellite's lifetime, when fuel approaches depletion, satellite operators may decide to omit these expensive manoeuvres to correct inclination and only control eccentricity. This prolongs the life-time of the satellite as it consumes less fuel over time, but the satellite can then only be used by ground antennas capable of following the north–south movement, satellite-tracking Earth stations.

===Polar orbits===
{{See also|Polar orbit}}
A polar orbit has an inclination of 90 degrees passing over the poles of the planet on each pass. These types of orbits are often used for earth observation and weather services.

===Sun-synchronous orbits===
{{See also|Sun-synchronous orbit}}
This is a special type of orbit that [[Nodal precession|precesses]] at the same rate that the sun moves along the ecliptic, causing the satellite to rise over a fixed location on the earth's surface at the same [[mean solar time]] every day.

These orbits have an inclination governed by the equation:
:<math>\cos(i) \approx -\left( \frac{T}{3.795\text{ hr}} \right)^\frac{7}{3}</math>

where <math>i</math> is the orbital inclination, and <math>T</math> is the orbital period.