LEO
Key Points
- Orbit close to Earth compared with higher regimes
- Supports lower latency than higher orbits
- Common in satellite communications and Earth observation
- Requires orbital movement and constellation coordination
- Completes orbit in short period compared with geostationary systems
- Lower altitude reduces propagation delay and can improve observation detail
Definition
LEO is low Earth orbit, an orbital regime relatively close to Earth used by satellites in communications and observation systems.
Concept
LEO is a space systems term for satellites operating in low Earth orbit. Lower orbital altitude reduces propagation delay and supports higher-resolution observation or lower-latency communications compared with higher orbits. LEO is used in satellite communications, Earth observation, navigation support, and distributed space architectures. LEO systems often rely on constellations because individual spacecraft move quickly relative to the surface, requiring frequent handoffs and continuous constellation management.
Explainer
LEO, or low Earth orbit, is an orbital regime close to Earth where satellites move relatively quickly and complete an orbit in a short period compared with higher-altitude systems. It operates as a deployment layer for communications, imaging, and other space services by placing spacecraft in an altitude range that reduces delay and can improve observation detail.
LEO is used in satellite communications, Earth observation, scientific missions, and broadband constellations. Constraints include orbital motion, constellation management, frequent handoffs, atmospheric drag at lower altitudes, and the need for many spacecraft to maintain continuous coverage.
Failure modes include coverage gaps, handoff issues, orbital decay, inter-satellite coordination problems, and ground integration errors. Tradeoffs involve lower latency and improved resolution versus more spacecraft and higher operational complexity.
LEO matters because it enables modern distributed satellite services with different performance characteristics than geostationary systems. Cross-industry relevance is strong in telecommunications, aerospace, Government & Defence, and remote sensing.