The free fall machine (FFM) is designed to permit the development of small biological sample such as cell cultures with a simulated effect of micro-gravity, under free fall conditions.
[1] The free fall machine (FFM) addresses some of the problems of the simple horizontal clinostat or random positioning machines (RPM).
In a typical machine samples are allowed to cycle between free fall for about a metre down a column (micro-gravity simulation, near "0 g") and a "bounce" back to the top of the column that is intended to be so fast (c. 20 g for 20 ms) that it is undetected by the biological sample.
Long duration of hyper-gravity is often simulated by machines such as the large diameter centrifuge (LDC) at ESA.
The sample therefore effectively grows at near 0 g. This science article is a stub.