Explain why an astronaut in an orbiting satellite has a feeling of weightlessness

Explanation

The weight of a body is defined as the gravitational force exerted on the body by the Earth. It is directed towards the centre of the Earth. When the astronaut is on the surface of the Earth, his weight acts vertically downward. At the same time, the surface of the Earth exerts a force of reaction which is equal in magnitude and opposite in direction to the weight of the astronaut. It is due to this reaction that the astronaut feels his weight.
When the astronaut is in a spaceship orbiting around the Earth, he feels weightless although the gravitational force acting on the astronaut is not zero
The spaceship is an accelerated frame of reference. The spaceship as well as the astronaut are attracted towards the centre of the Earth. They have the same centripetal acceleration, equal to the acceleration due to gravity at that height. Therefore, the astronaut cannot produce any action on the floor of the spaceship. The floor also does not exert a force of reaction on the astronaut. In the absence of the reaction, the astronaut feels weightless lower thrust by the second-stage gives the correct horizontal velocity to the satellite to put it into a stable circular orbit. This velocity is determined by the altitude of the satellite. Hence a minimum two-stage rocket is necessary to launch a satellite into an orbit around the Earth.