Weightlessness In A Satellite

Apparent weight is not gravity itself but the normal reaction force a surface exerts on a body, which is what our senses register as weight. In a circular orbit both the space station and the astronaut are in continuous free fall toward the Earth, accelerating inward at the same value $g^{\prime }$ because gravitational acceleration is independent of mass. Since both fall together with identical acceleration, the astronaut presses on no surface and the floor pushes back with zero normal force, producing the sensation of weightlessness. The claim that gravity is zero at that height is false, since orbital gravity is still a large fraction of its surface value and in fact provides the centripetal force. The Sun-cancellation option is physically baseless at low orbit. The zero-mass option is wrong because mass is an invariant property and never vanishes. This matches the NCERT explanation of weightlessness in satellites. A sanity check confirms that without gravity the station could not orbit at all, so weightlessness must arise from shared free fall, not absent gravity.