Imagine you are an astronaut and just got thrown off a spaceship. there is no friction and no gravity. describe your motion.

Your motion is at a constant, unchanging speed, in a straight line, at the same speed and in the same direction as you were going at the instant you lost touch with the ship.  

Nothing you can do with your body can change your speed or the direction you're going, EXCEPT throwing items or objects away from you.

I hope you have some loose pieces that you don't need.

By the way . . . The question says that there is no gravity, but that's false.  If there's a star or a planet anywhere in Creation, then there's a pair of gravitational forces between you and it, trying to pull you together.

And even if there isn't a single star or planet anywhere in the Universe, there's still that spaceship you just got thrown off of.  There's a pair of gravitational forces between you and your ex-spaceship, pulling you back together.

gas and liquid