To train astronauts to live and work in the weightless environment on the International Space Station, NASA employs a number of techniques and facilities that simulate microgravity. Engineers at the NASA Johnson Space Center (JSC) have developed a new system called the Active Response Gravity Offload System (ARGOS) that provides a simulated reduced gravity environment within a confined interior volume for astronauts to move about and/or equipment to be moved about as if they were in a different gravity field. Each astronaut/item is connected to an overhead crane system that senses their actions (walking or jumping, for example) and then lifts, moves, and descends them as if they had performed the action in a specified reduced gravity.
ARGOS has a simulation range from full gravity to microgravity. The system utilizes input/feedback sensors, fast-response motor controllers, and custom- developed software algorithms to provide a constant force offload that simulates reduced gravity. It can interface with a wide range of subjects, including humans, robots, and inanimate objects.
The ARGOS system attaches to a human subject in a gimbal and/or harness through a cable. The system then maintains a constant offload of a portion of the subject’s weight through the cable to simulate reduced gravity. The system supports movements in all three dimensions consistent with the selected gravity level. Front/back and left/right movements are supported via a trolley on an overhead runway and bridge drive system, and up/down movements are supported via a precisely positioned cable. The system runs at a very high cycle rate, and constantly receives feedback to ensure the human subject’s safety.
The technology is cost effective because most of the “big ticket” components are based on commercially available hoist systems. ARGOS has commercial possibilities wherever individuals have to interact with heavy objects within a confined volume. Potential applications include material handling in a warehouse or industrial facility; physical therapy; commercial shipping/transportation of packages, luggage, or other heavy objects; moving vans; personal hoist systems for home, office, or garage; assembly and maintenance; and automotive repair.