15 articles
Dawn-dusk orbit
A dawn-dusk orbit is a sun-synchronous orbit that stays aligned with the day-night terminator, so the satellite crosses the equator around 6 a.m. or 6 p.m. in perpetual sunrise or sunset.
Geocentric orbit
A geocentric orbit, also called an Earth-centered orbit, is the path of any object circling Earth, from low orbits to the geostationary ring at 35,786 km.
Geostationary transfer orbit
The geostationary transfer orbit, also known as the geosynchronous transfer orbit or GTO, is a highly elliptical parking orbit with perigee near low Earth orbit and apogee at geostationary altitude.
Heliocentric orbit
A heliocentric orbit, also known as a solar orbit, is an orbit around the Sun, followed by every planet, dwarf planet, asteroid, and comet in the solar system.
High Earth orbit
High Earth orbit (HEO) is defined as an orbit around Earth above 35,786 kilometers or 2,000 kilometers. It covers geostationary and highly elliptical orbits used for communications and astronomy.
Highly elliptical orbit
A highly elliptical orbit (HEO) is an Earth orbit with eccentricity above 0.25, used by Molniya and Tundra satellites to serve high northern latitudes where geostationary coverage fails.
List of orbits
The list of orbits catalogs the recurring paths spacecraft follow around Earth, the Moon, the Sun, or balance points between two bodies, grouped by altitude and purpose.
Low Earth orbit
Low Earth orbit (LEO) is the region of Earth orbit between roughly 200 and 2,000 km altitude, where satellites complete a revolution in 88 to 127 minutes.
Low lunar orbit
A low lunar orbit (LLO) is an orbit around the Moon tens to about a hundred kilometers up, completed roughly every two hours and destabilized by lunar mascons.
Lunar orbit
A lunar orbit, also called a selenocentric orbit, is the path of a spacecraft around the Moon, first achieved by the Soviet Luna 10 in 1966.
Medium Earth orbit
Medium Earth orbit, also called Intermediate Circular Orbit, is the band from 2,000 to 36,000 kilometers up, home to GPS, Galileo, BeiDou, GLONASS, and broadband satellites.
Molniya orbit
A Molniya orbit is a highly elliptical 12-hour Earth orbit inclined at 63.4°, letting satellites dwell for hours over high northern latitudes where geostationary satellites cannot serve.
Parking orbit
A parking orbit is a temporary low orbit into which a spacecraft is inserted to coast before departing for its destination, such as the Moon or geostationary orbit.
Polar orbit
A polar orbit is an orbit inclined 90 degrees in which a spacecraft passes over both poles, the standard choice for Earth mapping and environmental monitoring.
Supersynchronous orbit
A supersynchronous orbit, or supersynchronous transfer orbit, is an Earth orbit above geosynchronous altitude of 35,786 km, used for fuel-saving transfers to GEO and satellite disposal.