Concept Study of a Passive Reduced-Gravity Simulator for Training Astronauts

Abstract

Each manned space exploration mission requires a significant amount of microgravity or reduced-gravity (physical) simulation before the mission to train astronauts and verify some mission requirements. An appealing new simulation technique for such an application must be effective, safe, and inexpensive. This paper presents a novel design concept of a reduced-gravity simulator for simulating human walking in a controllable reduced-gravity condition. Designed based on the spring-based passive gravity-balancing technology, the 3D passive reduced-gravity simulator has sufficient mobility to allow the attached human to walk while feeling less gravity effects. The system is completely passive and thus, it is intrinsically stable, safe and cost effective. A concept study of the new mechanism using multibody dynamics simulations including a full-scale human dynamics model has demonstrated the effectiveness of the device for offloading any desired amount of gravity force. A scaled-down nonhuman experimental test using a walking robot and a passive jump device is currently underway.