ABSTRACT
It is generally thought that gravity is zero on an object travelling at constant velocity in space. An object travelling in the open space is obviously subjected to acceleration forces coming from the spacecraft itself. The spacecraft is also submitted to gravity forces resulting from the other massive objects, planets, stars, etc. In addition to these gravity effects, at least in the solar system, a phenomenon of friction due to the solar wind and radiation pressure induces deceleration in the direction of Sun. In satellites, the weight compensation is located only at the center of mass. Free floating objects in the spacecraft can also be submitted to gravity effects. Such objects orbit Earth in different orbital planes and their distance oscillates, with the same period as the orbit, corresponding to an inward acceleration.
