Free-fall time is a theoretical astrophysical measurement of how long a cloud of gas, dust, or a star would take to collapse into a single point if internal pressure suddenly vanished. In aerospace contexts, it can also refer to the duration an object spends in unpowered ballistic descent before aerodynamic drag or a parachute intervenes.
Heard on the job
Calculate the free-fall time from apogee to atmospheric entry interface so we can time the drogue deployment.