Mass remains constant but weight is the force with which the earth pulls the body to itself. Weight is felt by the support given to us by the floor.
Weightlessness is a result of free fall.
Orbital motion is a form of free fall. The concepts of mass and weight are first elicited from students and an acceptable definition written on the board. An analytical balance is displayed and with a nutcracker in the left pan. Now a thread is used to connect one leg of the nutcracker to the top of the balance and the pans are still balanced. The experiment is promptly performed and results discussed.