Abstract
Random Positioning Machines (RPMs) have been used since many years as a ground-based model to simulate microgravity. In this review we discuss several aspects of the RPM. Recent technological development has expanded the operative range of the RPM substantially. New possibilities of live cell imaging and partial gravity simulations, for example, are of particular interest. For obtaining valuable and reliable results from RPM experiments, the appropriate use of the RPM is of utmost importance. The simulation of microgravity requires that the RPM's rotation is faster than the biological process under study, but not so fast that undesired side effects appear. It remains a legitimate question, however, whether the RPM can accurately and reliably simulate microgravity conditions comparable to real microgravity in space. We attempt to answer this question by mathematically analyzing the forces working on the samples while they are mounted on the operating RPM and by comparing data obtained under real microgravity in space and simulated microgravity on the RPM. In conclusion and after taking the mentioned constraints into consideration, we are convinced that simulated microgravity experiments on the RPM are a valid alternative for conducting examinations on the influence of the force of gravity in a fast and straightforward approach.
Highlights
Gravity is an omnipresent force on Earth, and all living organisms have evolved under the influence of constant gravity
We attempt to answer this question by mathematically analyzing the forces working on the samples while they are mounted on the operating Random Positioning Machines (RPMs) and by comparing data obtained under real microgravity in space and simulated microgravity on the RPM
We have recently reported another approach to upgrading the RPM by installing a commercial CO2 incubator onto the rotating frames
Summary
Gravity is an omnipresent force on Earth, and all living organisms have evolved under the influence of constant gravity. Some of the symptoms observed in space, such as wasting muscle mass and decreasing bone density, are typically diagnosed in the elderly as well [1,2,3]. It is assumed that the gravity vector needs to point in a specific direction for a minimal period of time in order to allow biological systems, like cells, to adapt to the gravity vector. The RPM is typically used to examine slow processes, which are observed at least on the timescale of hours. It remains a legitimate question whether the RPM can reliably simulate microgravity. A summary is provided on the latest technical development as well as new applications of the RPM
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
