Multi-Orbit Satellite Architectures: Combining LEO, MEO, and GEO

The first commercial satellite operators had a straightforward choice: geostationary orbit (GEO). At 35,786 km altitude over the equator, a GEO satellite appears stationary from the ground, covers roughly one-third of Earth's surface, and requires no handoff as users move across its coverage area. For decades, this simplicity made GEO the default for communications and broadcast.

The proliferation of low Earth orbit (LEO) constellations has complicated the picture. SpaceX Starlink demonstrated that LEO broadband could deliver consumer-grade latency at multi-hundred megabit speeds. But LEO has its own constraints, and the most capable satellite operators are now thinking about multi-orbit architectures that combine the strengths of LEO, medium Earth orbit (MEO), and GEO.

The Three Orbital Regimes

Low Earth Orbit (LEO): 200–2,000 km

LEO satellites are close to Earth, which means:

• Low latency: at 550 km, round-trip latency is approximately 20–40 ms, comparable to good terrestrial broadband and suitable for real-time communications and time-sensitive applications
• High path loss at GHz frequencies is manageable: closer range reduces free-space path loss, enabling smaller ground terminals or higher data rates
• Fast orbital period: a LEO satellite at 550 km completes an orbit in about 95 minutes, meaning a single satellite provides only brief contact windows from any ground point. Large constellations (hundreds to thousands of satellites) are required for continuous global coverage
• Atmospheric drag: LEO satellites below about 600 km experience meaningful atmospheric drag and require periodic orbit maintenance burns; below ~400 km, lifetimes without propulsion are measured in months

Medium Earth Orbit (MEO): 2,000–35,786 km

MEO is the orbital home of navigation constellations (GPS at 20,200 km, Galileo at 23,222 km, GLONASS at 19,100 km) and some communications satellites:

• Intermediate coverage: a MEO satellite covers more of Earth's surface than a LEO satellite, requiring smaller constellations for global coverage
• Intermediate latency: at GPS altitude, one-way latency is approximately 67 ms; at lower MEO (8,000 km), closer to 27 ms
• Van Allen radiation: the inner and outer Van Allen radiation belts (roughly 1,000–6,000 km and 13,000–60,000 km) are hostile to electronics; MEO satellites must either avoid these altitudes or use radiation-hardened components, which adds cost and reduces performance
• O3b MEO broadband: SES's O3b mPOWER system operates at ~8,062 km, providing low-latency broadband to the tropics and mid-latitudes with a constellation of tens of satellites versus thousands required for LEO

Geostationary Orbit (GEO): 35,786 km

• Large coverage per satellite: three GEO satellites can cover most of Earth's surface (excluding polar regions)
• No handoff required: fixed pointing antennas on the ground, no tracking required
• High latency: minimum one-way latency of approximately 240 ms; round-trip 500–600 ms, which is problematic for real-time interactive applications and TCP-based protocols
• Limited spectrum and slots: GEO arc slots and spectrum assignments are finite resources managed by the ITU; popular arc positions are congested
• High launch cost: reaching GEO requires significantly more delta-v than LEO, meaning less payload mass for the same launch vehicle

Why Multi-Orbit Makes Sense

The appeal of multi-orbit architectures is that different applications have different requirements, and no single orbit excels at all of them:

• Broadband internet: LEO for low latency interactive use; GEO for broadcast distribution, VSAT business services in remote areas where LEO coverage is incomplete or terminal cost is prohibitive
• Maritime and aviation: LEO provides high-throughput, low-latency connectivity; GEO provides reliable fallback coverage especially in equatorial regions and for legacy equipment; MEO (O3b-class) provides an intermediate option
• Government and defense: proliferated LEO for resilience (individual satellite loss has low impact on overall capability); GEO for persistent coverage of fixed areas; MEO for navigation and PNT

Implementation: Inter-Orbit Links and Ground Segment Complexity

Building a multi-orbit architecture requires more than operating satellites at different altitudes. The ground segment must seamlessly route traffic across orbital layers, dynamically select the optimal path based on latency, throughput, and link availability, and manage handoffs as LEO satellites move overhead. This requires sophisticated network management software and potentially optical or RF inter-satellite links to interconnect the orbital layers.

SES has explicitly positioned its combined O3b MEO and GEO fleet as a multi-orbit offering. Telesat's Lightspeed LEO constellation is designed to work alongside its existing GEO fleet. And Intelsat's GEO assets are being positioned alongside planned or partner LEO services.

Implications for the Industry

Multi-orbit architectures raise barriers to entry, since only well-capitalized operators can build and operate assets across multiple orbital regimes. They also shift competitive advantage from any individual satellite to the integrated network management layer. For customers, they promise service quality and resilience that single-orbit networks cannot match.

Monitor satellite constellations across all orbital regimes with the SpaceNexus satellite tracker, and analyze orbital slot and spectrum regulatory filings through the compliance module.