🔍 Key Concepts

• Geostationary orbit vs polar orbit and how each affects coverage at sea • The typical altitude of geostationary satellites used for global communications • Difference between Inmarsat (maritime comms) and COSPAS-SARSAT (distress alerting/search and rescue) systems

💭 Think About

• Ask yourself which orbit type allows a satellite to appear fixed over one point on Earth, making it easier for ships’ antennas to stay pointed at it. • Consider what approximate altitude is commonly associated with geostationary communications satellites. • Think about whether Inmarsat relies on its own communications satellites or on the COSPAS-SARSAT distress system for maximum routine communications coverage.

✅ Before You Answer

• Verify which choice correctly describes geostationary orbit above the equator (both orbit type and rough altitude). • Eliminate any option that uses polar orbit, since that is not how Inmarsat’s primary comms satellites are deployed. • Confirm that COSPAS-SARSAT is a separate SAR/distress alert system, not the main Inmarsat communications constellation.