What is the difference between a satellite and a constellation?

The main difference between a satellite and a constellation is that a satellite is a single orbiting object, while a constellation is a group of satellites working together as a system.

Here's a more detailed breakdown:

Satellite:

• Definition: A single, artificial object placed into orbit around the Earth, Moon, or another celestial body.
• Purpose: Satellites serve a wide range of purposes, including communication, observation (weather, Earth imaging), navigation (GPS), and scientific research.
• Coverage: A single satellite's coverage area is limited by its orbital altitude and the sensor or antenna field of view it carries. A single satellite cannot provide continuous, global coverage.
• Example: A single weather satellite providing regional weather updates.

Constellation:

• Definition: A group of artificial satellites that work together to provide continuous or near-continuous coverage over a specific area, or the entire globe. They are typically designed with complementary orbital planes.
• Purpose: Constellations are primarily designed for applications requiring global or near-global coverage, such as broadband internet access (Starlink, OneWeb), precise global navigation (GPS, Galileo), and continuous Earth observation.
• Coverage: By strategically placing multiple satellites in different orbital planes, a constellation ensures that at least one satellite is always within view of a given location on Earth.
• Example: The Starlink constellation aims to provide global internet coverage using thousands of satellites. The GPS constellation allows for accurate location tracking anywhere on Earth.

Here's a table summarizing the key differences:

In summary, while a single satellite serves a specific purpose within its limited coverage area, a satellite constellation is a coordinated system of multiple satellites designed to provide continuous and often global coverage for more demanding applications.