RNR MARS SystemR N R Mechanical Advantage Systems (M. A. R. S.) The Mars System is a pre rigged pre packaged 4: 1 mechanical advantage lifting lowering system using a double camming pulley. It is designed to lift and lower live loads and as such may be used for rescue or entry into confined spaces. All components used in the Mars System exceed the current NFPA, ANSI and OSHA requirements. No more fumbling about looking for parts to build a mechanical advantage