A thing in motion will continue at the same speed and in the same direction until another force acts upon it. OK - you have spotted that drag from air can quic

A thing in motion will continue at the same speed and in the same direction until another force acts upon it. OK - you have spotted that drag from air can quickly slow down an object here on earth and that thus an object in a vacuum will spin (or whatever) for a lot longer without air slowing it down. But drag from air is not the only force likely to affect the motion of your theoretical object.