Definition
An object placed in orbit around the Earth that transmits signals used for navigation, communication, or weather observation. In aviation, satellites form the space segment of Global Navigation Satellite Systems (GNSS) such as GPS, broadcasting precise timing and position data that aircraft receivers use to determine location, altitude, and time.
Plain English
A device circling the Earth that sends signals down to aircraft. Receivers on the plane use those signals to work out where the aircraft is and what time it is, accurately enough for navigation.
Context Anchor
Seen in discussions of GPS, navigation, and aircraft systems that use signals from space.
Derivation
From the Latin satelles, meaning 'attendant' or 'follower' — someone who travels alongside another. The word was applied to small bodies orbiting larger ones (like moons), and later to man-made objects placed in orbit. The image is useful: a satellite is an 'attendant' that follows the Earth in its orbit, faithfully sending signals back down.
Why Pilots Care
Modern navigation, approaches, and many weather and traffic services depend on satellite signals. Knowing that position information comes from a constellation of orbiting transmitters helps a pilot understand why signal geometry, outages, and interference matter — and why a backup plan is needed if satellite-based navigation becomes unreliable.
Grounding Statement
Picture several man-made objects high above Earth sending timing signals down to the aircraft so its equipment can work out its location.
Intuition Check
Do not read satellite here as a TV service or a natural moon. In this aviation context, it means a man-made object orbiting Earth and sending signals used for navigation or communication.
Example Sentence 1
The GPS receiver locked onto signals from several satellites and displayed the aircraft's position on the moving map.
Example Sentence 2
Poor satellite geometry can reduce the accuracy of the navigation solution.