Weightlessness experienced while orbiting the earth in a spaceship is a result of

Weightlessness in an orbiting spaceship is a result of acceleration, specifically the state of continuous free fall. While gravity is still present and significant at orbital altitudes [t4], the spacecraft and its occupants are accelerating toward the Earth at the same rate due to gravity [t8]. This centripetal acceleration is balanced by the spacecraft's tangential velocity, creating an orbital path [t5]. Because both the astronaut and the vehicle accelerate together, there is no normal force (the 'push' from a floor) to provide the sensation of weight [t4]. This environment is often termed microgravity, where the net acceleration relative to the cabin is nearly zero [t1][t9]. Thus, weightlessness is not caused by 'zero gravity' but by the condition of falling freely under the influence of gravitational acceleration without resistive support [t3][t10].

Sources

1. [1] https://ntrs.nasa.gov/api/citations/19930072850/downloads/19930072850.pdf