The phase of weightlessness may be observed in the following situations:

(i) When objects fall freely under gravity : For example, a lift goes down freely, or an airship showing a feat in which it falls freely for a few seconds in the mean whereas its flight, are in state of weightlessness.

(ii)When a satellite revolves in its orbit around the earth: Weightlessness poses many serious problems to the astronauts. It seems quite complex for them to control their positions. Everything in the moon has to be saved tied down.

(iii) When bodies are at null points in outer space : On a body shown up, the force of the earth goes on reducing, but at the similar time the gravitational force of the moon on the body goes on enhancing. At one point, the two gravitational forces may be equal and opposite and the net pull on the body converts to zero. This is zero gravity fields or the null point and the body in question is said to appear weightless.