Space Academy · Contents · Chapter 3 · Nederlandse versie
Chapter 3: Satellites and their sensors
Bus and payload, and the types of military satellites: communications, navigation, optical and infrared imagery, radar (SAR), signals interception, missile warning, weather and space surveillance — with what each sensor can and cannot do.
3.1Bus and payload
Every satellite consists of a platform that keeps it alive and a payload that does the actual work.
Read §3.1 →3.2Communications (SATCOM)
Links beyond the horizon — from narrowband for a soldier to broadband for a drone.
Read §3.2 →3.3Navigation (PNT)
Four global systems provide position and, above all, precise time.
Read §3.3 →3.4Optical and infrared imagery
A telescope that can tell cars apart from hundreds of kilometres away — as long as it is light and not cloudy.
Read §3.4 →3.5Radar imagery (SAR)
A satellite that brings its own light: radar sees through cloud and at night.
Read §3.5 →3.6Signals interception (SIGINT/ELINT)
Listening from space: locating radars, radios and data links without transmitting anything.
Read §3.6 →3.7Missile warning
Infrared sensors that see a missile's hot exhaust seconds after launch.
Read §3.7 →3.8Weather, space weather and space surveillance
Knowing what the weather does on Earth, what the Sun does in space, and what happens in orbit around you.
Read §3.8 →3.9What sensors cannot do
Every sensor has blind spots — and an opponent plans their activities exactly inside them.
Read §3.9 →