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📐 Orbital Elements

Apogee & Perigee

📘 Definition
In an elliptical orbit around Earth, the apogee is the point farthest from Earth's centre, and the perigee is the point closest to Earth. For a circular orbit, apogee equals perigee. In a GTO (Geostationary Transfer Orbit), the perigee is typically 250 km and the apogee 35,786 km. A satellite travels fastest at perigee and slowest at apogee (Kepler's second law). These terms apply only to Earth orbits; for orbits around the Sun, the equivalent terms are aphelion and perihelion.
250 km
GTO Perigee
35,786 km
GTO Apogee
418 km
ISS Perigee
422 km
ISS Apogee
EARTH PERIGEE Closest point Fastest speed APOGEE Farthest point Slowest speed