* Weightlessness in Orbit: In orbit, you are in a state of constant freefall. You are falling towards the Earth, but your horizontal velocity keeps you from hitting the ground. This means you are essentially weightless.
* Scales Measure Weight: Scales measure the force of gravity acting on your mass (which we call weight). Since you are weightless in orbit, there's no force for the scale to measure.
Think of it this way:
Imagine a scale inside a freely falling elevator. As the elevator plummets, you would feel weightless, and the scale would read zero. Orbit is similar; you are constantly "falling" around the Earth, so you experience weightlessness.
Important Note: You still have mass in orbit! Your mass is the amount of matter you contain, and it doesn't change just because you are weightless.
