Medium Earth Orbit (MEO) is positioned between Low Earth Orbit (LEO) and Geostationary Orbit (GEO). Satellites in MEO are primarily used for navigation and certain communication applications. Here are the key details about MEO:

Orbital Characteristics:

  • Altitude: Ranges between approximately 2,000 kilometers (1,200 miles) and 35,786 kilometers (22,236 miles) above Earth’s surface.
  • Orbital Period: Satellites in MEO complete an orbit in several hours, typically ranging from 2 to 24 hours.

Primary Applications:

  • Navigation and Global Positioning: The most well-known application of MEO is for satellite navigation systems. The Global Positioning System (GPS), GLONASS (Russia), Galileo (European Union), and BeiDou (China) constellations operate in MEO.
  • Communications: Some communication satellites, especially those intended to serve polar regions, are placed in MEO because GEO satellites don’t cover these areas well.

Advantages:

  • Lower Latency than GEO: Due to its closer proximity to Earth compared to GEO, MEO offers reduced communication latency.
  • Broader Coverage than LEO: Each MEO satellite can cover a larger portion of the Earth than a LEO satellite, requiring fewer satellites for global coverage.
  • Longer Satellite Visibility: Compared to LEO, MEO satellites remain in view of a ground station for a longer period, reducing the need for frequent handovers.

Challenges:

  • Orbital Maintenance: MEO satellites may require occasional adjustments to their orbits to maintain proper positioning.
  • Cost and Complexity: Launching and maintaining MEO satellites can be more expensive and complex than LEO deployments, but generally less so than GEO.

Difference from Other Orbits:

  • Low Earth Orbit (LEO): Closer to Earth, ideal for Earth observation, satellite internet, and space stations. Offers the lowest latency for satellite communication.
  • Geostationary Orbit (GEO): Positioned at approximately 35,786 kilometers, satellites in GEO appear stationary relative to a point on Earth. Primarily used for TV broadcasting, weather observation, and certain communication applications.

MEO satellites offer a balance between the proximity of LEO and the fixed position of GEO. Their primary value today lies in satellite navigation systems that provide global positioning, timing, and navigation services essential for various civilian, commercial, and military applications.