Underwater VR for Astronaut Training

Abstract

Pools are excellent places for testing many nautical technologies, as well as training divers or astronauts in simulated weightlessness. However, for extensive astronaut training underwater, a large pool is necessary. The Neutral Buoyancy Laboratory (NBL) is an astronaut training facility and located at the Sonny Carter Training Facility, near the Johnson Space Center in Houston, Texas, containing 23 million liters of water. In Europe, Blue Abyss Ltd. is currently building the world’s largest and deepest indoor pool in Cornwall, also having space applications in mind. We believe that a VR solution can overcome the needs for large pools for astronaut training as space equipment can be well-simulated in virtual reality. To this end, we combined a full-face diving mask with a custom built VR headset for simulating a space environment. Besides constructing a water-tight VR headset, a precise tracking system to determine the position and orientation in space plays an important role. We use an outside-in tracking system consisting of four cameras in watertight housings, mounted on aluminium rails, covering a 2×3.5 meter experimental area, which enable us to track reference markers placed on the underwater VR diving mask. To calibrate this system, a rectangular cuboidal structure with reference markers is placed in the experimental area, which additionally serves as a handrail to perform basic Extra Vehicular Activity (EVA) tasks. The position tracking of the underwater headset and mirroring of physical objects in VR enables the user to move physically in the virtual environment as well as interact with the physical objects, such as the handrail. Due to the underwater environment, refraction at different media needs to be taken into account for both calibration and tracking.