Like,imagine if I had a way to make something grow in mass for a split second, and I moved it forward while it had more mass,and then moved it backwards when it had less mass. If I can keep doing that, a force arises even if I don't need any propellant,right?

Is that possible to do? Is there way to make them ass of a system oscillate briefly? Could that be something that would make it easier for us to go to Mars?