Low-Earth orbit (LEO) satellites are satellites that orbit the Earth at altitudes ranging from approximately 111 to 1,242 miles (180 to 2,000 km) above the Earth’s surface. These satellites are situated much closer to Earth compared to higher orbits like geostationary orbit (GEO), which is more than 22,000 miles (35,000 km) above the Earth. LEO satellites have gained significant attention in recent years due to their potential for providing various services, including satellite internet, Earth observation, communication, scientific research, and more.
LEO satellites work by continuously orbiting the Earth at high speeds. Unlike geostationary satellites, which remain stationary relative to a specific point on Earth’s surface, LEO satellites move quickly across the sky. This rapid movement allows them to cover different areas of the Earth’s surface during their orbits. To provide continuous coverage over a larger area, LEO satellites are often deployed in constellations, which are groups of satellites working together to ensure that at least one satellite is visible from any point on Earth at any given time.
For satellite internet purposes, LEO constellations offer several advantages over traditional geostationary satellites:
- Lower Latency: LEO satellites have lower signal travel time (latency) compared to geostationary satellites because they are much closer to the Earth. This is particularly important for real-time applications like video conferencing, online gaming, and other interactive activities.
- Faster Data Transmission: The shorter distance between LEO satellites and ground stations allows for faster data transmission speeds.
- Global Coverage: LEO satellite constellations, with their multiple satellites in orbit, can provide more comprehensive and global coverage, including remote and underserved areas.
- Reduced Launch Costs: LEO satellites can be launched using smaller rockets, reducing launch costs compared to the larger rockets required for geostationary satellites.
Several companies, including SpaceX’s Starlink, Amazon’s Project Kuiper, and Telesat, are actively deploying or planning LEO satellite constellations to provide high-speed internet access to remote and rural areas around the world. These constellations consist of hundreds or even thousands of small satellites working together to deliver internet connectivity to ground-based user terminals.
However, there are challenges associated with LEO satellite constellations, such as managing orbital debris, coordinating satellite traffic to prevent collisions, and addressing potential interference with other satellite systems. Nevertheless, the increasing interest and investment in LEO satellites are driving innovation in space technology and satellite communications, with the potential to revolutionize the way we access the internet and communicate globally.