What impact does atmospheric drag have on satellites?

• A. It increases their speed
• B. It has no impact
• C. It causes orbital decay
• D. It helps stabilize their orbits

Answer: (C)

Atmospheric drag has a significant impact on satellites, primarily leading to a phenomenon known as orbital decay. As satellites travel through the upper layers of the Earth's atmosphere, they encounter residual atmospheric particles, which create friction. This force acts opposite to the satellite’s motion, gradually reducing its speed.

As the speed decreases, the satellite can no longer maintain its altitude, and begins to spiral down towards Earth. This process of losing altitude is what is referred to as orbital decay. Over time, if not corrected with propulsion systems, the satellite will eventually re-enter the denser parts of the atmosphere and may burn up upon re-entry or fall to the Earth's surface.

Understanding this concept is crucial for mission planning, as operators must account for atmospheric drag when determining the lifespan and operational parameters of satellites in low Earth orbit. Thus, the correct answer highlights the critical role that atmospheric drag plays in influencing the trajectory and operational longevity of satellites.