Answer: weight , mass 
Step-by-step explanation:
Mass is defined as the amount of matter contained in a body. It is measured in units of kg, g and mg. 
Weight of an object is the force acting on an object by virtue of its mass. 
weight=
 
 
m = mass
g = acceleration due to gravity
As the value of g keeps changing from earth to space, the weight of the person would also keep changing. The mass of the person will remain same .