https://www.youtube.com/watch?v=tgRMAVoHRbk see this video and watch the guy moving around the space station. He flies forward, then instantly changes direction by 90 degress simply by touching his fingertips to the wall. Im not sure how he is negating his momentum, but I imagine that even in zero gravity effort is required to change the direction of a moving mass, or we could or go out there and throw planets around with our hands.