Here's the breakdown:
* Earth's Gravity: Earth exerts a constant gravitational pull on everything around it, including satellites. This pull would cause a satellite to fall back to Earth if it wasn't moving fast enough.
* Orbital Velocity: To counteract gravity and maintain a stable orbit, a satellite needs to be moving at a specific speed called orbital velocity. This velocity is high enough to constantly "fall" around the Earth, but not so high that it escapes Earth's gravity.
* LEO's Lower Gravity: LEO is closer to Earth, meaning the gravitational pull is stronger. This stronger pull requires a higher orbital velocity to maintain the orbit.
Imagine a satellite like a ball on a string. If you swing the ball slowly, it falls to the ground (like a satellite falling to Earth). But if you swing it fast enough, it will circle around you (like a satellite orbiting Earth).
Here are some key takeaways:
* The higher the orbit, the slower the required orbital velocity. This is because the gravitational pull is weaker further away from Earth.
* Satellites in LEO need to travel at speeds of around 7.8 km/s (17,500 mph) to maintain their orbit. This is incredibly fast, but it's necessary to counter Earth's strong gravitational pull.
So, in essence, satellites in LEO need to travel very fast because they are constantly fighting against Earth's gravity to stay in orbit.
