Mrrzy,
Penny's last sentence focuses on the difference between mass and weight. In space, the mass of a person is the same as on earth whereas the weight is zero.

I do understand your concern about 'primitive' for all its unwanted associations, but when I look into my Webster's I find that 'primitive' covers the sense Penny has meant, whereas 'ancient' doesn't. 'Ancient' doesn't relate to a society still being here today for testing, whereas 'primitive' does.

Wolfgang