What are the four main satellite orbit types?

What are the four main satellite orbit types?

• A. GEO, HEO, MEO, and GPS
• B. GEO, HEO, MEO, and LEO
• C. Polar, Equatorial, Sun-Synchronous, and Retrograde
• D. Circular, Elliptical, Hyperbolic, and Parabolic

Answer: (B)

Satellites are grouped by how far they orbit Earth and how long each orbit takes. The four main types are Low Earth Orbit, Medium Earth Orbit, High Earth Orbit, and Geostationary Orbit. Low Earth Orbit covers roughly up to 2,000 km above the surface; satellites there complete orbits in about 90 to 120 minutes and are commonly used for imaging and many constellations. Medium Earth Orbit ranges roughly from 2,000 to 35,786 km, with longer orbital periods and includes navigation satellite systems like GPS, which sits at about 20,200 km. High Earth Orbit describes highly elliptical paths that spend most of their time far from Earth but come close enough to provide coverage opportunities—Molniya-type missions are a classic example. Geostationary Orbit sits at about 35,786 km above the equator, with a 24-hour period so the satellite appears fixed relative to the Earth, ideal for continuous communications and weather observation. The other options mix in orbital planes or shapes rather than these altitude-based categories, or include a specific system as if it were a separate orbit type. For instance, GPS is a representative satellite system that happens to operate in Medium Earth Orbit, not a distinct orbit type on its own.

Satellites are grouped by how far they orbit Earth and how long each orbit takes. The four main types are Low Earth Orbit, Medium Earth Orbit, High Earth Orbit, and Geostationary Orbit.

Low Earth Orbit covers roughly up to 2,000 km above the surface; satellites there complete orbits in about 90 to 120 minutes and are commonly used for imaging and many constellations. Medium Earth Orbit ranges roughly from 2,000 to 35,786 km, with longer orbital periods and includes navigation satellite systems like GPS, which sits at about 20,200 km. High Earth Orbit describes highly elliptical paths that spend most of their time far from Earth but come close enough to provide coverage opportunities—Molniya-type missions are a classic example. Geostationary Orbit sits at about 35,786 km above the equator, with a 24-hour period so the satellite appears fixed relative to the Earth, ideal for continuous communications and weather observation.

The other options mix in orbital planes or shapes rather than these altitude-based categories, or include a specific system as if it were a separate orbit type. For instance, GPS is a representative satellite system that happens to operate in Medium Earth Orbit, not a distinct orbit type on its own.