🔍 Key Concepts

• Basic characteristics of the Iridium LEO (Low Earth Orbit) satellite constellation • Difference between number of satellites and number of orbital planes • Typical orbital period for LEO satellites around 780 km altitude

💭 Think About

• First, think about how long it takes a low‑Earth‑orbit satellite to go around the Earth once. Is it closer to 90 minutes or several hours? • Compare the stated inclination (55°) with what you know about Iridium’s near‑polar coverage – does 55° sound like it would give full global coverage, including polar regions? • Consider whether Iridium is known for a very large number of satellites or a smaller number with many beams each. Which of the options best matches what you’ve heard about Iridium’s architecture?

✅ Before You Answer

• Verify which statement matches known Iridium orbital parameters: inclination (near‑polar or mid‑latitude?), altitude, and period. • Check whether the number of satellites and planes given is consistent with a truly global commercial communication system. • Think about whether a 30‑mile beam footprint is realistic for worldwide handheld coverage from space and whether 48 beams per satellite fits typical Iridium design.