Low Earth orbit is any orbit around Earth with an altitude roughly between 160 and 2,000 kilometers, low enough that objects there complete a full orbit in about 90 minutes to two hours. It is the most heavily used orbital regime for crewed spaceflight and Earth observation, home to the International Space Station, most communications and imaging satellites, and the great majority of tracked orbital debris. Because atmospheric drag is still measurable at these altitudes, uncrewed objects here gradually lose altitude and eventually reenter unless periodically boosted.
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The Wikipedia Low Earth orbit article, checked 2026-09-12, defines the term and its thresholds but names no individual as having proposed or introduced it. Concept Domain Connections
Associated With
Skylab orbited in low Earth orbit
Sources
1. Wikipedia (space and spaceflight articles)
Wikimedia FoundationLow Earth orbit, International Space Station orbit-decay sectionQuote, Low Earth orbit, International Space Station orbit-decay section
The station's orbit decays by about 2 km/month (1.2 mi/month) and consequently needs re-boosting a few times a year.
Low Earth orbit (Wikipedia)
Lead section
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 than 0.25.
In Group: Earth Orbit Types, Lead sentence
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 than 0.25.
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