---
title: "Free fall machine"
chunk: 1/1
source: "https://en.wikipedia.org/wiki/Free_fall_machine"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:52:53.947295+00:00"
instance: "kb-cron"
---

A free fall machine (FFM) is a mechanism designed to permit the development of small biological samples, such as cell cultures, with a simulated effect of micro-gravity under free fall conditions.


== Description ==
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. The sample therefore experiences an average gravity of near 0 g.
Long duration of hyper-gravity is often simulated by machines such as the large diameter centrifuge (LDC) at ESA. To simulate partial-gravity (between simulated 0 and Earth's gravity, 1, such as Mars or Moon gravitational strengths) conditions, an RPM can also be used.


== See also ==
Clinostat
Gravitropism
Large Diameter Centrifuge
Random Positioning Machine


== References ==


== External links ==
ETH Space Biology Free Fall Machine