In order to resolve some of the many variables associated with lunar surface vehicle design and to evaluate early analyses and assumptions, an operating model vehicle was constructed and tested over a wide range of surface conditions. The resulting test data permitted making preliminary performance comparisons of 4, 6, and 8-wheel, split-track and full-track vehicles, and predictions of prototype performance.
The conflicting requirements imposed by the variable mission and surface conditions stress the necessity for an adaptable or flexible locomotion system. Common wheel or track systems which employ fixed relationships with the ground cannot provide the combination of reliability, efficiency, traction, stability, and maneuverability so important to lunar missions.
The test vehicle which employed the Northrop “Walking Beam Suspension” system permits the efficient use of scuff steering, and provides many of the advantages of a tracked vehicle at generally higher mechanical efficiencies and improved reliability. It also promises unique advantages in performance and maneuverability, as well as operational adaptability and multitask capabilities.