Low-Earth Orbit Satellites

Low Earth Orbit (LEO) satellites are communication and observation satellites that orbit below 2000 km from the earth's surface, positioned below the lower Van Allen radiation belt. They move at very high speeds and do not maintain a fixed position relative to Earth, requiring multiple satellites to provide continuous coverage.

Key Features of LEO Satellites

• Constellation requirement − A network of LEO satellites is needed for global coverage as their orbits are not geostationary and they constantly move across the sky.

• Lower power output − These satellites are not as powerful as MEO and GEO satellites due to their proximity to Earth and lower power requirements.

• Handoff communication − Due to their high orbital speeds, satellites move in and out of earth stations' range frequently, requiring data handoff between satellites for uninterrupted communication.

• Energy efficient − LEO satellites require much less energy to reach orbit compared to MEO and GEO satellites, and their amplifiers consume less power due to shorter transmission distances.

• Cost-effective deployment − They are relatively inexpensive compared to other satellite systems, making them suitable for providing communication services to underdeveloped regions.

• Remote connectivity − LEO satellites enable network establishment in remote terrains where laying terrestrial infrastructure is not feasible.

Types and Applications

Communication Satellites

Used for low-cost data communication, voice services, and internet connectivity. Modern LEO constellations like Starlink and OneWeb provide broadband internet access globally.

Earth Observation Satellites

Employed for monitoring ground features, weather patterns, and environmental changes. Their close proximity to Earth provides clearer, higher-resolution imagery compared to satellites in higher orbits.

Scientific Research Platforms

The International Space Station (ISS) serves as a research laboratory for conducting experiments in microgravity environments and testing spacecraft systems for future missions.

Advantages and Disadvantages

Conclusion

LEO satellites offer cost-effective, low-latency communication solutions through constellation networks orbiting below 2000 km altitude. While requiring multiple satellites for continuous coverage, they provide significant advantages in terms of signal strength, launch costs, and global connectivity for remote areas.