Which statement below best describes the space segment of the NAVSTAR Global Positioning System (GPS)?

• A. It is a geosynchronous constellation of 24 satellites in 6 orbital planes, with each plane inclined 55 degrees.
• B. It is a MEO constellation of 24 satellites in 6 orbital planes, with each plane inclined 55 degrees.
• C. It is a GEO constellation of five satellites equally spaced around the equator.
• D. It is a HEO constellation of 12 satellites, 6 with apogees over the Arctic region and 6 with apogees over the Antarctic region, together providing global coverage.

Answer: (B)

Global Positioning System space segment operates in medium Earth orbit, not a stationary orbit. The satellites circle the Earth at about 20,200 km altitude and take roughly 12 hours to complete a pass. They are arranged in six orbital planes with a 55-degree inclination, totaling 24 satellites. This layout provides reliable global visibility from most latitudes, allowing receivers to see multiple satellites at once for accurate positioning. A geosynchronous or equatorial-only setup would not deliver the same global geometry or coverage, and a highly elliptical or sparse constellation would degrade performance. So describing the space segment as a mid‑Earth, 24-satellite system in six 55-degree inclined planes best reflects how GPS is designed.