How often does a GPS satellite orbit the Earth?

The correct answer is that a GPS satellite orbits the Earth every 12 hours. This means that each satellite completes two full orbits in a 24-hour period. GPS satellites are positioned in Medium Earth Orbit (MEO) at an altitude of approximately 20,200 kilometers (about 12,550 miles) above the Earth's surface. This orbit allows them to effectively cover the entire surface of the Earth and provide accurate location data to receivers on the ground.

The 12-hour orbit time is essential for maintaining GPS functionality, as it enables satellites to provide continuous coverage across the globe. Two completed orbits per day also contribute to the system's robustness, allowing for multiple satellites in the sky to improve the accuracy of positioning data.

Other orbit times, such as 6 hours, 18 hours, or the option of every 24 hours, do not align with the established orbital mechanics of GPS satellites and would result in inadequate coverage and accuracy in positioning services. Thus, the correct understanding of the orbital period is critical for comprehending how GPS technology operates effectively.