Lunar orbit in a long-lasting orbit, at 28° inclination, and successfully completed its mission after one and a half years. PFS-2 was placed in a particularly unstable orbital inclination of 11°, and lasted only 35 days in orbit before crashing into the lunar surface. Lunar orbit In astronomy, lunar orbit (also known as a selenocentric orbit) is the orbit of an object around the Moon. As used in the space program, this refers not to the orbit of the Moon about the Earth, but to orbits by various manned or unmanned spacecraft around the Moon. The altitude at apoapsis (point farthest from
Low Earth orbit millimeters, which are too small to be visible from Earth-based observatories. Low Earth orbit A low Earth orbit (LEO) is defined by Space-Track.org as an Earth-centered orbit with at least 11.25 periods per day (an orbital period of 128 minutes or less) and an eccentricity less than 0.25. Most of the manmade objects in space are in LEO orbits. A histogram of the mean motion of the cataloged objects shows that the number of objects drops significantly beyond 11.25. There is a large variety of other sources that define LEO in terms of altitude. The altitude of an object in