Earth orbit rendezvous (EOR) is a method for conducting round trip human flights to the Moon, involving the use of space rendezvous to assemble, and possibly...

Lunar orbit rendezvous (LOR) is a process for landing humans on the Moon and returning them to Earth. It was utilized for the Apollo program missions in...

rendezvous (/ˈrɒndeɪvuː/) is a set of orbital maneuvers during which two spacecraft, one of which is often a space station, arrive at the same orbit and...

different rendezvous possibilities. The alternatives included Earth-orbital rendezvous (EOR), lunar-orbital rendezvous (LOR), Earth and lunar rendezvous, and...

Earth orbits the Sun at an average distance of 149.60 million km (92.96 million mi), or 8.317 light-minutes, in a counterclockwise direction as viewed...

Lunar orbit rendezvous (LOR) used on the United States NASA Apollo program missions to Earth's moon during 1969 to 1972, as opposed to Earth orbit rendezvous...

spaceflight, a lunar orbit (also known as a selenocentric orbit) is an orbit by an object around Earth's Moon. In general these orbits are not circular....

Geocentric orbit: An orbit around the planet Earth, such as that of the Moon or of artificial satellites. Selenocentric orbit (named after Selene): An orbit around...

either the direct ascent or Earth orbit rendezvous, the working group instead selected a third option, Lunar Orbit Rendezvous (LOR). LOR had a mass requirement...

A medium Earth orbit (MEO) is an Earth-centered orbit with an altitude above a low Earth orbit (LEO) and below a high Earth orbit (HEO) – between 2,000...

Near Earth Asteroid Rendezvous – Shoemaker (NEAR Shoemaker), renamed after its 1996 launch in honor of planetary scientist Eugene Shoemaker, was a robotic...

The Moon orbits Earth in the prograde direction and completes one revolution relative to the Vernal Equinox and the stars in about 27.32 days (a tropical...

an orbital maneuver (otherwise known as a burn) is the use of propulsion systems to change the orbit of a spacecraft. For spacecraft far from Earth, an...

above Earth's equator, 42,164 km (26,199 mi) in radius from Earth's center, and following the direction of Earth's rotation. An object in such an orbit has...

considered three methods for the Moon mission: Earth orbit rendezvous (EOR), direct ascent, and lunar orbit rendezvous (LOR). A direct ascent configuration would...

A geosynchronous orbit (sometimes abbreviated GSO) is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours...

thus combined the Lunar Orbit Rendezvous method adopted by the Apollo program's lunar missions with the Earth Orbit Rendezvous method which had also been...

to the Moon or as heavy-lift derivatives for Earth orbit rendezvous. Ultimately, the lunar orbit rendezvous ("LOR") concept approved in 1962 rendered the...

high Earth orbit is a geocentric orbit with an apogee farther than that of the geosynchronous orbit, which is 35,786 km (22,236 mi) away from Earth. In...

transfer orbit (GTO) or geosynchronous transfer orbit is a highly elliptical type of geocentric orbit, usually with a perigee as low as low Earth orbit (LEO)...

Very low Earth orbit is a range of orbital altitudes below 400 km (250 mi), and is of increasing commercial importance in a variety of scenarios and for...

polar orbit is one in which a satellite passes above or nearly above both poles of the body being orbited (usually a planet such as the Earth, but possibly...

transatmospheric orbit (TAO) is an orbit around a celestial body in which the perigee of the orbit intersects with the defined atmosphere. Transatmospheric Earth orbits...

on a spacecraft. Halo orbits exist in any three-body system, e.g., a Sun–Earth–orbiting satellite system or an Earth–Moon–orbiting satellite system. Continuous...

A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less...

on the Lunar Gateway while retaining the planned use of a NRHO for orbital rendezvous between the Orion spacecraft and a lunar lander. Animations of the...

decision was choosing lunar orbit rendezvous over both direct ascent and Earth orbit rendezvous. A space rendezvous is an orbital maneuver in which two spacecraft...

design concept was for a proposed crewed circumlunar flight and the Earth orbit rendezvous (EOR) missions. It was initially considered for the Apollo lunar...

EOR could refer to: Earth Orbit Rendezvous, a proposed method for space missions to the Moon Electric orbit raising, a method in space technology of reaching...

A Sun-synchronous orbit (SSO), also called a heliosynchronous orbit, is a nearly polar orbit around a planet, in which the satellite passes over any given...