Assuming you are talking about the individual in space, Size and Weight changes in space due to the difference in gravity. Astronauts grow taller in space due to the micro-gravity they experience out of the earth's atmosphere.
It would not be:
Mass : Because mass is a measurement not dependent on gravity
Density : Astronauts do not blow out in bubbles once they leave the earth's atmosphere, therefore, we can deduct that density stays the same
