Explanation: The Global Positioning System (GPS) is designed to operate with a minimum of 24 satellites. These 24 satellites are distributed across six different orbital planes, ensuring worldwide coverage. This configuration allows a GPS receiver on Earth to consistently "see" at least four satellites simultaneously, which is the minimum required for an accurate three-dimensional position fix (latitude, longitude, altitude) and precise timing. While the constellation often has more than 24 active satellites (including spares or replacement units that can be brought online), 24 is the standard, fully operational number for continuous global coverage. Fewer satellites (like 8 or 18) would not provide reliable worldwide service, and 36 is more than the nominal operational requirement.