Polar orbit

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A polar orbit is an orbit in which a satellite passes above or nearly above both poles of the body (usually a planet such as the Earth, but possibly another body such as the Sun) being orbited on each revolution. It therefore has an inclination of (or very close to) 90 degrees to the equator. Except in the special case of a polar geosynchronous orbit, a satellite in a polar orbit will pass over the equator at a different longitude on each of its orbits.

Polar orbits are often used for earth-mapping-, earth observation- and reconnaissance satellites, as well as some weather satellites. The disadvantage to this orbit is that no one spot on the Earth's surface can be sensed continuously from a satellite in a polar orbit.

A satellite can hover over one polar area a large part of the time, albeit at a large distance, using a polar highly elliptical orbit with its apogee above that area. This is the principle behind a Molniya orbit.

[edit] See also

List of orbits
Vandenberg AFB Major United States launch location for polar orbits.

[edit] External links

Orbital Mechanics (Rocket and Space Technology)

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Orbits

Types

General	Box · Circular · Non-inclined · Elliptic (Highly Elliptical) · Graveyard · Hyperbolic trajectory · Inclined · Osculating · Parabolic trajectory · Capture · Escape · Semi-synchronous · Subsynchronous · Synchronous · Parking
Geocentric	Geosynchronous · Geostationary · Sun-synchronous · Low Earth · Medium Earth · Molniya · Near equatorial · Moon · Polar · Tundra
Other	Areosynchronous · Areostationary · Halo · Lissajous · Lunar · Heliocentric · Heliosynchronous

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Parameters

Classical orbital elements
<math>i\,\!</math> Inclination
<math>\Omega\,\!</math> Longitude of the ascending node
<math>e\,\!</math> Eccentricity

<math>\omega\,\!</math> Argument of periapsis
<math>a\,\!</math> Semi-major axis
<math>M_o\,\!</math> Mean anomaly at epoch

Other parameters
<math>v\,</math> True anomaly
<math>b\,</math> Semi-minor axis
<math>\epsilon\,</math> Linear eccentricity
<math>E\,</math> Eccentric anomaly

<math>L\,</math> Mean longitude
<math>l\,</math> True longitude
<math>T\,</math> Orbital period

Maneuvers

Bi-elliptic transfer · Geostationary transfer · Gravity assist · Hohmann transfer · Inclination change · Phasing · Rendezvous