Satellites aren’t just floating randomly in space; they orbit Earth in specific patterns, each offering unique advantages for different applications. The type of orbit directly impacts the coverage area a satellite can provide. Let’s explore some common types:

1. Low Earth Orbit (LEO):

• Altitude: 160-2,000 km above Earth
• Characteristics: Short orbital period (90-120 minutes), high data transmission speeds, good for high-resolution imaging and observation.
• Coverage Area: Limited to a specific region of Earth due to the low altitude.
• Examples: International Space Station, some Earth observation satellites.

2. Medium Earth Orbit (MEO):

• Altitude: 2,000-35,786 km above Earth
• Characteristics: Longer orbital period (2-12 hours), good for navigation and communication.
• Coverage Area: Wider than LEO, offering regional coverage but not global.
• Examples: GPS satellites, some communication satellites.

3. Geostationary Earth Orbit (GEO):

• Altitude: 35,786 km above Earth (over the equator)
• Characteristics: Orbital period matches Earth’s rotation (24 hours), appears stationary from Earth, ideal for broadcasting and communication.
• Coverage Area: Covers a large portion of the Earth, typically one-third of the globe, but limited to areas near the equator.
• Examples: Weather satellites, TV broadcasting satellites, some communication satellites.

4. Sun-Synchronous Orbit (SSO):

• Altitude: Typically 600-800 km
• Characteristics: Orbits with a consistent angle relative to the Sun, providing consistent lighting conditions for imaging.
• Coverage Area: Covers the entire Earth, but the coverage is specific to a particular time of day.
• Examples: Earth observation satellites, some weather satellites.

5. Polar Orbit:

• Altitude: Varies
• Characteristics: Passes over the Earth’s poles, providing coverage of the entire globe.
• Coverage Area: Global, but the coverage is not continuous, as the satellite passes over different regions at different times.
• Examples: Earth observation satellites, some weather satellites, reconnaissance satellites.

Each orbit type has its strengths and limitations, making them suitable for different applications. Satellite engineers carefully consider the purpose and coverage needs when selecting an orbit for a particular mission.

References

1. Types Of Satellites By Orbits, Functions, And Practical Uses
2. Catalog of Earth Satellite Orbits
3. Different Types of Satellite Orbits | Globalcom Satellite Phones
4. Understanding the 3 Types of Satellite Orbits: LEO, MEO, and GEO

Explore More

• How do satellite orbits affect the latency (delay) of communication?
• What are some emerging satellite orbit types, and what are their potential applications?
• How do the costs of launching and maintaining satellites vary based on their orbit type?
• How does the selection of a satellite orbit impact the design of the spacecraft itself?