What is a BMMD? How does it work?
BMMD stands for Body Mass Measuring Device used by astronauts, which is basically a spring mounted chair which measures mass as a measure of inertia. As you know, one experiences weightlessness inside a satellite and normal methods of measuring mass do not work. (like a common balance or a spring balance). The time period of oscillations which depends on the force constant and mass is used in measuring mass in BMMD used by an astronomer