lowEarth

Low Earth, in aerospace terminology commonly referred to as low Earth orbit (LEO), designates the region of space around Earth extending roughly from 160 kilometers (100 miles) to 2,000 kilometers (1,200 miles) above the planet’s surface. It is the domain where most artificial satellites, space stations, and human spaceflight missions operate due to relatively accessible launch requirements and short communication distances.

Characteristics of LEO include higher atmospheric density compared with higher orbits, which causes orbital drag that slowly reduces altitude over time. Objects in LEO travel at speeds around 7 to 8 kilometers per second to maintain orbit. The environment features space radiation, micro-meteoroids, and debris, all of which influence design, operations, and end-of-life planning. Because of these factors, satellites in LEO may require periodic boosts or deorbit maneuvers, especially at lower altitudes.

Uses in LEO encompass Earth observation, reconnaissance, telecommunications, scientific experiments, and human spaceflight. Notable examples include crewed space stations and a wide range of small satellites, including CubeSats. Within LEO, a variety of orbital types exist, such as sun-synchronous and polar orbits, tuned for imaging or constant lighting conditions, as well as equatorial or moderately inclined orbits for communications.

Challenges facing LEO operations include space debris management, collision avoidance, and regulatory measures to mitigate orbital congestion. End-of-life procedures often involve controlled deorbiting or propulsion to move objects to less congested disposal orbits.