| Term | Meaning |
|---|---|
| Orbit | The path a satellite follows around the Earth; altitude and shape determine what it can do (see chapter 2) |
| LEO / MEO / GEO / HEO | Low, medium, geostationary and highly elliptical orbit |
| Bus and payload | The "platform" (power, control, engine) and the useful load (camera, radar, transmitter) |
| Constellation | A group of satellites that together deliver one service, such as GPS or Starlink |
| Revisit | How often a satellite (or constellation) can observe the same point again |
| TT&C | Telemetry, Tracking & Command: the link used to control a satellite |
| SDA / SSA | Space Domain Awareness (formerly Space Situational Awareness): knowing what is in space and what it is doing |
| Counterspace | All means of disrupting, deceiving or destroying an opponent's space systems |
| ASAT | Anti-satellite weapon; DA-ASAT = direct-ascent (a missile from the ground) |
| RPO | Rendezvous and Proximity Operations: a satellite manoeuvring close to another |
| Space debris | Fragments in orbit; some stay up for decades and threaten everyone |
Space Academy · Contents · Chapter 1 · §1.3 · Nederlandse versie
§1.3 Key terms
The words that come back in every chapter.